NobleBlocks

National Center for University Entrance Examinations

UniversityTokyo, Japan

Research output, citation impact, and the most-cited recent papers from National Center for University Entrance Examinations (Japan). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
546
Citations
5.0K
h-index
30
i10-index
120
Also known as
Daigaku Nyushi CenterDokuritsu Gyōsei HōjinNational Center for University Entrance Examinations独立行政法人大学入試センター

Top-cited papers from National Center for University Entrance Examinations

An official systematic review of the European Respiratory Society/American Thoracic Society: measurement properties of field walking tests in chronic respiratory disease
Sally Singh, Milo A. Puhan, Vasileios Andrianopoulos, Nídia Aparecida Hernandes +4 more
2014· European Respiratory Journal931doi:10.1183/09031936.00150414

This systematic review examined the measurement properties of the 6-min walk test (6MWT), incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT) in adults with chronic respiratory disease. Studies that report the evaluation or use of the 6MWT, ISWT or ESWT were included. We searched electronic databases for studies published between January 2000 and September 2013. The 6-min walking distance (6MWD) is a reliable measure (intra-class correlation coefficients ranged from 0.82 to 0.99 in seven studies). There is a learning effect, with greater distance walked on the second test (pooled mean improvement of 26 m in 13 studies). Reliability was similar for ISWT and ESWT, with a learning effect also evident for ISWT (pooled mean improvement of 20 m in six studies). The 6MWD correlates more strongly with peak work capacity (r=0.59-0.93) and physical activity (r=0.40-0.85) than with respiratory function (r=0.10-0.59). Methodological factors affecting 6MWD include track length, encouragement, supplemental oxygen and walking aids. Supplemental oxygen also affects ISWT and ESWT performance. Responsiveness was moderate to high for all tests, with greater responsiveness to interventions that included exercise training. The findings of this review demonstrate that the 6MWT, ISWT and ESWT are robust tests of functional exercise capacity in adults with chronic respiratory disease.

17.9 A 105Gb/s 300GHz CMOS transmitter
Kyoya Takano, Shuhei Amakawa, Kosuke Katayama, Shinsuke Hara +4 more
2017161doi:10.1109/isscc.2017.7870384

“High speed” in communications often means “high data-rate” and fiber-optic technologies have long been ahead of wireless technologies in that regard. However, an often overlooked definite advantage of wireless links over fiber-optic links is that waves travel at the speed of light c, which is about 50% faster than in optical fibers as shown in Fig. 17.9.1 (top left). This “minimum latency” is crucial for applications requiring real-time responses over a long distance, including high-frequency trading [1]. Further opportunities and new applications might be created if the absolute minimum latency and fiber-optic data-rates are put together. (Sub-)THz frequencies have an extremely broad atmospheric transmission window with manageable losses as shown in Fig. 17.9.1 (top right) and will be ideal for building light-speed links supporting fiber-optic data-rates. This paper presents a 105Gb/s 300GHz transmitter (TX) fabricated using a 40nm CMOS process.

Cross-linguistic patterns in the acquisition of quantifiers
Napoleon Katsos, Chris Cummins, María José Ezeizabarrena Segurola, Anna Gavarró +4 more
2016· Proceedings of the National Academy of Sciences141doi:10.1073/pnas.1601341113

Learners of most languages are faced with the task of acquiring words to talk about number and quantity. Much is known about the order of acquisition of number words as well as the cognitive and perceptual systems and cultural practices that shape it. Substantially less is known about the acquisition of quantifiers. Here, we consider the extent to which systems and practices that support number word acquisition can be applied to quantifier acquisition and conclude that the two domains are largely distinct in this respect. Consequently, we hypothesize that the acquisition of quantifiers is constrained by a set of factors related to each quantifier's specific meaning. We investigate competence with the expressions for "all," "none," "some," "some…not," and "most" in 31 languages, representing 11 language types, by testing 768 5-y-old children and 536 adults. We found a cross-linguistically similar order of acquisition of quantifiers, explicable in terms of four factors relating to their meaning and use. In addition, exploratory analyses reveal that language- and learner-specific factors, such as negative concord and gender, are significant predictors of variation.

Antenna System Design for Improved Wireless Capsule Endoscope Links at 433 MHz
Md. Suzan Miah, Ahsan Noor Khan, Clemens Icheln, Katsuyuki Haneda +1 more
2019· IEEE Transactions on Antennas and Propagation117doi:10.1109/tap.2019.2900389

Wireless capsule endoscopy (WCE) systems are used to capture images of the human digestive tract for medical applications. The antenna is one of the most important components in a WCE system. In this paper, we present novel small antenna solutions for a WCE system operating at the 433 MHz ISM band along with a link budget analysis. The in-body capsule transmitter uses an ultrawideband outer wall conformal loop antenna, whereas the on-body receiver uses a printed monopole antenna with a partial ground plane. A colon-equivalent tissue phantom and CST Gustav voxel human body model were used for the numerical studies of the capsule antenna. The simulation results in the colon-tissue phantom were validated through <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vitro</i> measurements using a liquid phantom. According to the phantom simulations, the capsule antenna has −10 dB impedance matching from 309 to 1104 MHz. The ultrawideband characteristic enables the capsule antenna to tolerate the detuning effects due to electronic modules in the capsule and due to the proximity of various different tissues in gastrointestinal tracts. The same design methodology was applied to on-body antennas followed by <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vitro</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ex vivo</i> measurements for validation. The on-body antenna exceeds −10 dB impedance matching from 385 to 502 MHz both in simulations and measurements. The path loss for the radio link between an in-body capsule transmitter and an on-body receiver using our antenna solutions, in simulations and measurements, is less than 50 dB for any capsule orientation and location, ensuring sufficient signal level at the receiver, hereby enabling an improved capsule endoscope.

Why children differ in motivation to learn: Insights from over 13,000 twins from 6 countries
Yulia Kovas, Gabrielle Garon‐Carrier, Michel Boivin, Stephen A. Petrill +4 more
2015· Personality and Individual Differences81doi:10.1016/j.paid.2015.02.006

Little is known about why people differ in their levels of academic motivation. This study explored the etiology of individual differences in enjoyment and self-perceived ability for several school subjects in nearly 13,000 twins aged 9-16 from 6 countries. The results showed a striking consistency across ages, school subjects, and cultures. Contrary to common belief, enjoyment of learning and children's perceptions of their competence were no less heritable than cognitive ability. Genetic factors explained approximately 40% of the variance and all of the observed twins' similarity in academic motivation. Shared environmental factors, such as home or classroom, did not contribute to the twin's similarity in academic motivation. Environmental influences stemmed entirely from individual specific experiences.

Relationships Among Several Methods of Linearly Constrained Correspondence Analysis
Yoshio Takane, Haruo Yanai, Shin-ichi Mayekawa
1991· Psychometrika75doi:10.1007/bf02294498

This paper shows essential equivalences among several methods of linearly constrained correspondence analysis. They include Fisher's method of additive scoring, Hayashi's second type of quantification method, ter Braak's canonical correspondence analysis, Nishisato's type of quantification method, ter Braak's canonical correspondence analysis, Nishisato's ANOVA of categorical data, correspondence analysis of manipulated contingency tables, Böckenholt and Böckenholt's least squares canonical analysis with linear constraints, and van der Heijden and Meijerink's zero average restrictions. These methods fall into one of two classes of methods corresponding to two alternative ways of imposing linear constraints, the reparametrization method and the null space method. A connection between the two is established through Khatri's lemma.

Incident Electric Field Effect and Numerical Dosimetry for a Wireless Power Transfer System Using Magnetically Coupled Resonances
Sang Wook Park, Kanako Wake, Soichi Watanabe
2013· IEEE Transactions on Microwave Theory and Techniques72doi:10.1109/tmtt.2013.2274053

We conducted a dosimetry study of a wireless power transfer (WPT) system, which is based on magnetically coupled resonances. The electric and magnetic fields produced by the system have been calculated using the method of moments. We calculated the induced electric fields and the specific absorption rates in a Japanese adult male model by the scattered-field finite-difference time-domain method, taking into account both the incident electric and magnetic fields, and also by the impedance method, but only taking into account the incident magnetic fields. We discuss the differences between the results obtained by the two methods. We also discuss the compliance of the WPT system with international safety guidelines.

WDM RoF-MMW and linearly located distributed antenna system for future high-speed railway communications
Pham Tien Dat, Atsushi Kanno, Naokatsu Yamamoto, Testuya Kawanishi
2015· IEEE Communications Magazine66doi:10.1109/mcom.2015.7295468

In this article, we propose dual-hop network architecture capable of providing high-speed communications to high-speed trains (HSTs). The system uses a seamless fiber-millimeterwave system for backhaul transmission from a central station to antennas on trains, and a highspeed in-train Wi-Fi network. The system can be combined with signal processing and network control technologies to compensate for interference and the Doppler effect, and to reduce the number of handovers. It can realize seamless connectivity between the inside and outside of trains to avoid penetration loss and help organize the in-train network optimally to increase coverage and data rate. We present and discuss the possible network architecture and technologies that can help realize the proposed network. We also present a proof-of-concept demonstration on a high-performance seamless fiber- MMW system that can be applied for applications in backhaul networks. The proposed network can be an attractive solution to provide broadband services such as video on demand and high-speed mobile signals to users on HSTs.

Skills acquisition for novice learners after a point-of-care ultrasound course: does clinical rank matter?
Toru Yamada, Taro Minami, Nilam J. Soni, Eiji Hiraoka +3 more
2018· BMC Medical Education62doi:10.1186/s12909-018-1310-3

BACKGROUND: Few studies have compared the effectiveness of brief training courses on point-of-care ultrasound (POCUS) skill acquisition of novice attending physicians vs. trainees. The purpose of this study was to evaluate the change in POCUS image interpretation skills and confidence of novice attending physicians vs. trainees after a 1-day POCUS training course. METHODS: A 1-day POCUS training course was held in March 2017 in Japan. A standardized training curriculum was developed that included online education, live lectures, and hands-on training. The pre-course assessment tools included a written examination to evaluate baseline knowledge and image interpretation skills, and a physician survey to assess confidence in performing specific ultrasound applications. The same assessment tools were administered post-course, along with a course evaluation. All learners were novices and were categorized as trainees or attending physicians. Data were analyzed using two-way analysis of variance. RESULTS: In total, 60 learners attended the course, and 51 learners (85%) completed all tests and surveys. The 51 novice learners included 29 trainees (4 medical students, 9 PGY 1-2 residents, 16 PGY 3-5 residents) and 22 attending physicians (6 PGY 6-10 physicians, and 16 physicians PGY 11 and higher). The mean pre- and post-course test scores of novice trainees improved from 65.5 to 83.9% while novice attending physicians improved from 66.7 to 81.5% (p < 0.001). The post-course physician confidence scores in using ultrasound significantly increased in all skill categories for both groups. Both trainees and attending physicians demonstrated similar improvement in their post-course test scores and confidence with no statistically significant differences between the groups. The course evaluation scores for overall satisfaction and satisfaction with faculty members' teaching skills were 4.5 and 4.6 on a 5-point scale, respectively. CONCLUSIONS: Both novice trainees and attending physicians showed similar improvement in point-of-care ultrasound image interpretation skills and confidence after a brief training course. Although separate training courses have traditionally been developed for attending physicians and trainees, novice learners of point-of-care ultrasound may acquire skills at similar rates, regardless of their ranking as an attending physician or trainee. Future studies are needed to compare the effectiveness of short training courses on image acquisition skills and determine the ideal course design.

Professionalism Mini‐Evaluation Exercise for medical residents in Japan: a pilot study
Yusuke Tsugawa, Yasuharu Tokuda, Sadayoshi Ohbu, Tomoya Okubo +4 more
2009· Medical Education58doi:10.1111/j.1365-2923.2009.03437.x

CONTEXT: Assessing medical professionalism among medical residents is of great importance. The Professionalism Mini-Evaluation Exercise (P-MEX) is a tool for assessing professionalism that was developed, tested for reliability and validated in Canada. Prior to the present study, no Japanese version of the P-MEX had been tested. METHODS: We modified the P-MEX for use in Japan and tested it on medical residents in a Japanese teaching hospital. For each resident, eight evaluators completed the P-MEX forms. A total of 184 P-MEX forms were completed on 23 senior residents. The construct validity of the P-MEX was analysed by confirmatory factor analysis through structural equation modelling. The reliability of the P-MEX was tested using generalisability theory and a decision study. After performing the assessment and providing feedback to the residents, we conducted a survey on the residents' perceptions of the assessment. RESULTS: Results indicate content and construct validity. A confirmatory factor analysis revealed that factor loadings ranged from 0.58 to 0.96, indicating good construct validity except for one item (P12: Maintained appropriate boundaries with patients and colleagues). Structural equation modelling showed that adding new items developed in Japan to the P-MEX provided adequate factor validity. A decision study showed confidence intervals sufficiently narrow with as few as 10 evaluations, slightly more than the eight forms verified in Canada. Most residents stated that the items were reasonable and appropriate, the results of the assessment were consistent with their own self-evaluation and the assessment enhanced their motivation. CONCLUSIONS: Our study demonstrated good evidence of adequate reliability and validity of the P-MEX for the assessment of professionalism among Japanese residents. Moreover, the addition of new items developed in Japan provided adequate factor validity.

Impact of general medicine rotation training on the in-training examination scores of 11, 244 Japanese resident physicians: a Nationwide multi-center cross-sectional study
Yuji Nishizaki, Taro Shimizu, Tomohiro Shinozaki, Tomoya Okubo +3 more
2020· BMC Medical Education52doi:10.1186/s12909-020-02334-8

BACKGROUND: Although general medicine (GM) faculty in Japanese medical schools have an important role in educating medical students, the importance of residents' rotation training in GM in postgraduate education has not been sufficiently recognized in Japan. To evaluate the relationship between the rotation of resident physicians in the GM department and their In-Training Examination score. METHODS: This study is a nationwide multi-center cross-sectional study in Japan. Participants of this study are Japanese junior resident physicians [postgraduate year (PGY)-1 and PGY-2] who took the General Medicine In-Training Examination (GM-ITE) in fiscal years 2016 to 2018 at least once (n = 11,244). The numbers of participating hospitals in the GM-ITE were 381, 459, and 503 in 2016, 2017, and 2018.The GM-ITE score consisted of four categories (medical interview/professionalism, symptomatology/clinical reasoning, physical examination/procedure, and disease knowledge). We evaluated relationship between educational environment (including hospital information) and the GM-ITE score. RESULTS: A total of 4464 (39.7%) residents experienced GM department rotation training. Residents who rotated had higher total scores than residents who did not rotate (38.1 ± 12.1, 36.8 ± 11.7, and 36.5 ± 11.5 for residents who experienced GM rotation training, those who did not experience this training in hospitals with a GM department, and those who did not experience GM rotation training in hospitals without a GM department, p = 0.0038). The association between GM rotation and competency remained after multivariable adjustment in the multilevel model: the score difference between GM rotation training residents and non-GM rotation residents in hospitals without a GM department was estimated as 1.18 (standard error, 0.30, p = 0.0001), which was approximately half of the standard deviation of random effects due to hospital variation (estimated as 2.00). CONCLUSIONS: GM rotation training improved the GM-ITE score of residents and should be considered mandatory for junior residents in Japan.

Validation of the General Medicine in-Training Examination Using the Professional and Linguistic Assessments Board Examination Among Postgraduate Residents in Japan
Kazuya Nagasaki, Yuji Nishizaki, Masanori Nojima, Taro Shimizu +4 more
2021· International Journal of General Medicine47doi:10.2147/ijgm.s331173

Purpose: In Japan, the General Medicine In-training Examination (GM-ITE) was developed by a non-profit organization in 2012. The GM-ITE aimed to assess the general clinical knowledge among residents and to improve the training programs; however, it has not been sufficiently validated and is not used for high-stake decision-making. This study examined the association between GM-ITE and another test measure, the Professional and Linguistic Assessments Board (PLAB) 1 examination. Methods: Ninety-seven residents who completed the GM-ITE in fiscal year 2019 were recruited and took the PLAB 1 examination in Japanese. The association between two tests was assessed using the Pearson product-moment statistics. The discrimination indexes were also assessed for each question. Results: A total of 91 residents at 17 teaching hospitals were finally included in the analysis, of whom 69 (75.8%) were women and 59 (64.8%) were postgraduate second year residents. All the participants were affiliated with community hospitals. Positive correlations were demonstrated between the GM-ITE and the PLAB scores ( r = 0.58, p < 0.001). The correlations between the PLAB score and the scores in GM-ITE categories were as follows: symptomatology/clinical reasoning ( r = 0.54, p < 0.001), physical examination/procedure ( r = 0.38, p < 0.001), medical interview/professionalism ( r = 0.25, p < 0.001), and disease knowledge ( r = 0.36, p < 0.001). The mean discrimination index of each question of the GM-ITE (mean ± SD; 0.23 ± 0.15) was higher than that of the PLAB (0.16 ± 0.16; p = 0.004). Conclusion: This study demonstrates incremental validity evidence of the GM-ITE to assess the clinical knowledge acquisition. The results indicate that GM-ITE can be widely used to improve resident education in Japan. Keywords: in-training examination, validity, extrapolation, General Medicine In-Training Examination, Professional and Linguistic Assessments Board, medical knowledge, postgraduate medical education

Theoretical Predict of Half-Metals in Co-Cr-Fe-Al Alloys
Shoji Ishida, Shingo Kawakami, Setsuro Asano
2004· MATERIALS TRANSACTIONS46doi:10.2320/matertrans.45.1065

To theoretically examine the existence of half-metals in Co-Cr-Fe-Al alloys, band calculations were carried out for these alloys. Seeing energy dispersion curves E(k) of Co2CrAl with the Heusler structure, we find that the Fermi level intersects the E(k) curves in the majority-spin state but is located at the energy gap in the minority-spin state, that is, it is predicted that this stoichiometric Co2CrAl alloy is half-metallic. On the other hand, the half-metallic properties are not observed in the electronic structures of Co2FeAl. The composition dependence of electronic structures of Co2(Cr1−xFex)Al (x = 1/8—7/8) indicates that the alloys have the tendency to become half-metallic in the range of x < 5/8.

Microplatform for intercellular communication
Tadashi Nakano, Yu‐Hsiang Hsu, William C. Tang, Tatsuya Suda +4 more
200842doi:10.1109/nems.2008.4484375

A microplatform was designed, fabricated, and tested for demonstrating the propagation of molecular signals through a line of patterned HeLa cells expressing gap junction channels (HeLa Cx43 cells). The microplatform was capable of patterning cells onto a predefined design with lithography and surface chemical treatment. Lucifer Yellow was first used as a fluorescent marker to demonstrate the formation of functional gap junction channels between patterned HeLa Cx43 cells. The cells at one end of the cell line were next chemically stimulated to induce the propagation of intercellular calcium waves along the cell line, which was successfully monitored with Fluo4. The designed microplatform allowed intercellular communication over an arbitrary network topology of cells, which may provide new insight into mechanisms of intercellular communication.

Automated Japanese essay scoring system based on articles written by experts
Tsunenori Ishioka, Masayuki Kameda
200641doi:10.3115/1220175.1220205

We have developed an automated Japanese essay scoring system called Jess. The system needs expert writings rather than expert raters to build the evaluation model. By detecting statistical outliers of predetermined aimed essay features compared with many professional writings for each prompt, our system can evaluate essays. The following three features are examined: (1) rhetoric --- syntactic variety, or the use of various structures in the arrangement of phases, clauses, and sentences, (2) organization --- characteristics associated with the orderly presentation of ideas, such as rhetorical features and linguistic cues, and (3) content --- vocabulary related to the topic, such as relevant information and precise or specialized vocabulary. The final evaluation score is calculated by deducting from a perfect score assigned by a learning process using editorials and columns from the Mainichi Daily News newspaper. A diagnosis for the essay is also given.

The Impact of the Hospital Volume on the Performance of Residents on the General Medicine In-Training Examination: A Multicenter Study in Japan
Atsushi Mizuno, Yusuke Tsugawa, Taro Shimizu, Yuji Nishizaki +4 more
2016· Internal Medicine40doi:10.2169/internalmedicine.55.6293

Objective Although several studies have been conducted worldwide on factors that might improve residents' knowledge, the relationship between the hospital volume and the internal medicine residents' knowledge has not been fully understood. We conducted a cross-sectional study to compare the relationships of the hospital volume and hospital resources with the residents' knowledge assessed by the In-training Examination. Methods We conducted a retrospective survey and a clinical knowledge evaluation of postgraduate year 1 and 2 (PGY-1 and -2) resident physicians in Japan by using the General Medicine In-training Examination (GM-ITE) in 2014. We compared the ITE score and the hospital volume. Results A total of 2,015 participants (70.6% men; age, 27.3±2.9 years old) from 208 hospitals were retrospectively analyzed. Generalized estimating equations were used, and the results revealed that an increasing number of hospitalizations, decreasing staff number, decreasing age and PGY-2 were significantly associated with higher GM-ITE scores. Conclusion The hospital volume, such as the number of hospitalizations, is thus considered to have a positive impact on the GM-ITE scores.

Evaluation of frequency fluctuation in fiber-wireless link with direct IQ down-converter
Atsushi Kanno, Pham Tien Dat, Toshiaki Kuri, Iwao Hosako +3 more
201436doi:10.1109/ecoc.2014.6963972

We demonstrate 12-Gbaud QPSK signal transmission in a fiber-wireless link and compare a modulator-based optical two-tone generator and an optical heterodyning with free-running lasers. The obtained frequency fluctuation of the two-tone system meets the requirements of the radio regulations.

Difference in the general medicine in-training examination score between community-based hospitals and university hospitals: a cross-sectional study based on 15,188 Japanese resident physicians
Yuji Nishizaki, Keigo Nozawa, Tomohiro Shinozaki, Taro Shimizu +4 more
2021· BMC Medical Education34doi:10.1186/s12909-021-02649-0

Abstract Background The general medicine in-training examination (GM-ITE) is designed to objectively evaluate the postgraduate clinical competencies (PGY) 1 and 2 residents in Japan. Although the total GM-ITE scores tended to be lower in PGY-1 and PGY-2 residents in university hospitals than those in community-based hospitals, the most divergent areas of essential clinical competencies have not yet been revealed. Methods We conducted a nationwide, multicenter, cross-sectional study in Japan, using the GM-ITE to compare university and community-based hospitals in the four areas of basic clinical knowledge“. Specifically, “medical interview and professionalism,” “symptomatology and clinical reasoning,” “physical examination and clinical procedures,” and “disease knowledge” were assessed. Results We found no significant difference in “medical interview and professionalism” scores between the community-based and university hospital residents. However, significant differences were found in the remaining three areas. A 1.28-point difference (95% confidence interval: 0.96–1.59) in “physical examination and clinical procedures” in PGY-1 residents was found; this area alone accounts for approximately half of the difference in total score. Conclusions The standardization of junior residency programs and the general clinical education programs in Japan should be promoted and will improve the overall training that our residents receive. This is especially needed in categories where university hospitals have low scores, such as “physical examination and clinical procedures.”

Estimating Comparable Scores Using Surrogate Variables
Michelle Liou, Philip E. Cheng, Ming-Yen Li
2001· Applied Psychological Measurement31doi:10.1177/01466210122032000

The possibility of using surrogate variables (e.g., school grades, other test scores, examinee background information) as replacements for common items predicting sample-selection bias between groups was investigated. The problem was specified as an incomplete data problem of comparability studies and was addressed using nonequivalent groups. A general model for estimating complete data (fitted) distributions through covariates is proposed (including common-item scores and surrogate variables as special cases). Model parameters are estimated using the EM algorithm. Standard errors of comparable scores are derived under the proposed model. Data from an empirical example examined the use of surrogate variables for establishing score comparability.

Experimental Demonstrations of All-Optical Phase-Multiplexing Using FWM-Based Phase Interleaving in Silica and Bismuth-Oxide HNLFs
Guo-Wei Lu, Kazi S. Abedin, Tetsuya Miyazaki
2009· Journal of Lightwave Technology31doi:10.1109/jlt.2008.928962

We propose an all-optical phase-interleaving technology based on dual-pump four-wave mixing (FWM) in highly nonlinear fiber (HNLF). The proposed all-optical phase-interleaving technology is applied in an all-optical phase-multiplexing scheme to successfully phase-multiplex 2times or 3 times 10-Gb/s DPSK-WDM signals to a 20- or 30-Gb/s DPSK in non-return-to-zero (NRZ) formats. The proposed all-optical phase multiplexing scheme is demonstrated using dual-pump FWM in highly nonlinear silica and bismuth fibers. In contrast with optical time-division multiplexing technology, the proposed all-optical phase-multiplexing technology does not require pulse-carving, thus offering a high spectral-efficiency. Differential precoder for each input tributary is operated independently, and no additional encoder or postcoder is required to recover the original data after demodulation on the receiver side.