• Title/Summary/Keyword: Group codes

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Performance Analysis of the Symbol Grouping SLM Scheme for PAPR Reduction of OFDM System (OFDM시스템의 PAPR 저감을 위한 심벌 그룹핑 SLM 기법의 성능분석)

  • Choi Ik-Young;Son Sung-Chan;Oh Chang-Heon
    • Journal of Digital Contents Society
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    • v.5 no.2
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    • pp.143-150
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    • 2004
  • In this paper, we propose and analyze a new scheme which uses the same scramble codes to each group after symbol grouping to reduce the PAPR (peak-to-avenge power ratio) problem in OFDM system. The conventional SLM scheme randomizes OFDM symbols entered into IFFT block by several scramble codes and then transmits the lowest one among PAPRs. Therefore, the SLM scheme can reduce the additional information as many as the number of grouped OFDM symbols by using same scramble codes after M grouping of sub-carriers. It can also improve PAPR performance more than conventional SLM scheme when we use scramble codes as same as those numbers of SLM scheme.

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Accuracy of administrative claim data for gastric adenoma after endoscopic resection

  • Ga-Yeong Shin;Hyun Ho Choi;Jae Myung Park;Sang Yoon Kim;Jun Young Park;Donghoon Kang;Yu Kyung Cho;Sung Soo Kim;Myung-Gyu Choi
    • Clinical Endoscopy
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    • v.56 no.3
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    • pp.325-332
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    • 2023
  • Background/Aims: Administrative databases provide valuable information for large-cohort studies. This study aimed to evaluate the diagnostic accuracy of an administrative database for resected gastric adenomas. Methods: Data of patients who underwent endoscopic resection for benign gastric lesions were collected from three hospitals. Gastric adenoma cases were identified in the hospital database using International Classification of Diseases (ICD) 10-codes. The non-adenoma group included patients without gastric adenoma codes. The diagnostic accuracy for gastric adenoma was analyzed based on the pathological reports of the resected specimen. Results: Among 5,095 endoscopic resections with codes for benign gastric lesions, 3,909 patients were included in the analysis. Among them, 2,831 and 1,078 patients were allocated to the adenoma and non-adenoma groups, respectively. Regarding the overall diagnosis of gastric adenoma with ICD-10 codes, the sensitivity, specificity, positive predictive value, and negative predictive value were 98.7%, 88.5%, 95.2%, and 96.8%, respectively. There were no significant differences in these parameters between the tertiary and secondary centers. Conclusions: Administrative codes of gastric adenoma, according to ICD-10 codes, showed good accuracy and can serve as a useful tool to study prognosis of these patients in real-world data studies in the future.

The Use Criteria and Appropriateness of Korean Classification of Diseases(KCD) Focused on Emmeniopathy (월경병을 중심으로 본 한국표준질병사인분류(KCD)의 사용 기준과 적합성)

  • Kang, You-Jeong;Lee, In-Seon;Cho, Hye-Sook;Lee, Seung-Hwan;Bae, Geung-Mee
    • The Journal of Korean Obstetrics and Gynecology
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    • v.24 no.4
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    • pp.126-149
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    • 2011
  • Purpose: KCDO-3(Korean Classification of Diseases(Oriental Medicine)-third edition) being used in January, 2010 accepted the KCD(Korean Classification of Diseases) and added disease pattern and syndrome of oriental medicine. But, the diagnoses of oriental medicine are too uncertain to express in A00-Z99(KCD). In this case, you should choose in U codes under the KCD use guidelines, but U codes are not capable of representing the symptoms too. So, we suggest the use criteria and consider the weakness of the U codes with medical records of patients who visited with amenorrhea or oligomenorrhea. Methods: We referred medical records of patients who visited oriental obstetrics and gynecology from January 1st to December 31st, 2010. From among them, we set up 122 patients who related with emmeniopathy as target group and searched codes distribution based on medical records. And we described that the process of choosing appropriate codes based on the medical records of 49 amenorrhea or oligomenorrhea patients. Results and Conclusions: The emmeniopathy is divided into menstrual disorder, amenorrhea and systemic disorders at the period of menstruation. And emmeniopathy is expressed in some codes such as N91, N92, N93, N94, U321, U77. When a patient visit hospital, a doctor should choose causal codes when there is confirmed diagnosis. Otherwise, a doctor chooses symptom codes. And if there are more than two diagnosis consistent with definition of chief condition, a doctor should code the first listed diagnosis as a chief condition. Because KCD-5 is classified according to western medical diagnosis, it is difficult to choose in KCD-5 when we diagnosed with disease pattern and syndrome of oriental medicine. But U codes are also deficient to express various condition of emmeniopathy. So we should add 'deficiency and detriment of the thoroughfare and conception vessels', 'prolonged menstruation' and various systemic disorders at the period of menstruation.

A Measurement Study of Body Types for Clothing Construction (의복구성(衣服構成)을 위한 계량적(計量的) 체형연구(體型硏究))

  • Jeong, Ok-Im
    • Journal of the Ergonomics Society of Korea
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    • v.5 no.1
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    • pp.19-28
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    • 1986
  • To study the body trunk form which is essential to clothing constructions, necessary body sizes were measured indirect1y from 216 unmarried women from 19 to 24 years old by a photographic network method. The results are obtained as follow; 1) In this study of body type measurements, the four factors of bust, abdomen, column and hip size have been divided into four-stage intervals and given the body type codes 1, 2, 3 and 4, with 1 designating the size difference of the factor with the minimum size difference of the factor with the maximum size difference from waist size. These body type codes can be easily, linguistically interpreted. In this study, among $4^4=256$ possible body types, 54 types appeared frequently. These 54 types are integrated into 6 groups of types by clustering analysis. Representative types of each group are types 3333 and 2333 in group 1, 2233, 1233 and 1332 in group 2, 2222, 1222 and 1223 in group 3, 2223 in group 4, 2323 and 2322 in group 5, and 3323, 3223 and 3322 in group 6. In the types of groups 1, 2, and 3, the change is mainly in bust size, and in the types of group 4. is single type. In the types of group 5 the change is mainly in hip size, and in the types by groups 6 the change is mainly in abdomen size and hip size. 2) The analysis by measuring the four elements of body trunk in reference to waist size is scientific and grading of similar styles is possible in clothing construction. 3) Assuming that the human body is oval, using the calculating method, the size of girth, which cannot be measured by the indirect measuring method, is obtained approximate to actual size, with an error of ${\pm}2.8cm$.

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The Influential Factors on High School Students' School Dress Code Compliance (고등학생들의 학교 외모규제 준수에 영향을 미치는 요인)

  • Lee, Jung-Hyun;Ko, Sun-Young;Lee, Yoon-Jung
    • Journal of Korean Home Economics Education Association
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    • v.24 no.1
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    • pp.49-59
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    • 2012
  • This research aimed at identifying the influential factors on high school students' dress code compliance. Specifically, the relationship between the perceived strength and importance of dress codes and dress code compliance, and the relationship between dress code compliance and creativity, self esteem, and school adaptation were examined. For this purpose, reliability tests, multiple regressions, and t-tests were conducted using the data collected from 866 male and female students from six Co-Ed high schools located in Seoul. The results are as follows. First, the more students perceived the school dress codes to be stronger and more important, they were more likely to comply to the dress codes. Second, compared to the low-compliance group, the high-compliance group had higher self-esteem and creativity. Third, compared to the low-compliance group, the high-compliance group showed better adaptation to their teachers, classes, and school rules. However, the two groups were not significantly different in terms of their adaptation to peer groups.

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Neutronics analysis of TRIGA Mark II research reactor

  • Rehman, Haseebur;Ahmad, Siraj-ul-Islam
    • Nuclear Engineering and Technology
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    • v.50 no.1
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    • pp.35-42
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    • 2018
  • This article presents clean core criticality calculations and control rod worth calculations for TRIGA (Training, Research, Isotope production-General Atomics) Mark II research reactor benchmark cores using Winfrith Improved Multi-group Scheme-D/4 (WIMS-D/4) and Program for Reactor In-core Analysis using Diffusion Equation (PRIDE) codes. Cores 133 and 134 were analyzed in 2-D (r, ${\theta}$) and 3-D (r, ${\theta}$, z), using WIMS-D/4 and PRIDE codes. Moreover, the influence of cross-section data was also studied using various libraries based on Evaluated Nuclear Data File (ENDF/B-VI.8 and VII.0), Joint Evaluated Fission and Fusion File (JEFF-3.1), Japanese Evaluated Nuclear Data Library (JENDL-3.2), and Joint Evaluated File (JEF-2.2) nuclear data. The simulation results showed that the multiplication factor calculated for all these data libraries is within 1% of the experimental results. The reactivity worth of the control rods of core 134 was also calculated with different homogenization approaches. A comparison was made with experimental and reported Monte Carlo results, and it was found that, using proper homogenization of absorber regions and surrounding fuel regions, the results obtained with PRIDE code are significantly improved.

An inter-comparison between ENDF/B-VIII.0-NECP-Atlas and ENDF/B-VIII.0-NJOY results for criticality safety benchmarks and benchmarks on the reactivity temperature coefficient

  • Kabach, Ouadie;Chetaine, Abdelouahed;Benchrif, Abdelfettah;Amsil, Hamid
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2445-2453
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    • 2021
  • Since the nuclear data forms a vital component in reactor physics computations, the nuclear community needs processing codes as tools for translating the Evaluated Nuclear Data Files (ENDF) to simulate nuclear-related problems such as an ACE format that is used for MCNP. Errors, inaccuracies or discrepancies in library processing may lead to a calculation that disagrees with the experimentally measured benchmark. This paper provides an overview of the processing and preparation of ENDF/B-VIII.0 incident neutron data with NECP-Atlas and NJOY codes for implementation in the MCNP code. The resulting libraries are statistically inter-compared and tested by conducting benchmark calculations, as the mutualcomparison is a source of strong feedback for further improvements in processing procedures. The database of the benchmark experiments is based on a selection taken from the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP handbook) and those proposed by Russell D. Mosteller. In general, there is quite good agreement between the NECP-Atlas1.2 and NJOY21(1.0.0.json) results with no substantial differences, if the correct input parameters are used.

Static and fatigue performance of short group studs connector in novel post-combination steel-UHPC composite deck

  • Han Xiao;Wei Wang;Chen Xu;Sheraz Abbas;Zhiping Lin
    • Steel and Composite Structures
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    • v.50 no.6
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    • pp.659-674
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    • 2024
  • Casting Ultra High-Performance Concrete (UHPC) on an orthotropic steel deck and forming a composite action by connectors could improve the steel deck fatigue performance. This study presents the mechanical performance of a proposed post-combination connection between UHPC and steel, which had a low constraint effect on UHPC shrinkage. A total of 10 push-out tests were conducted for static and fatigue performance investigations. And the test results were compared with evaluation methods in codes to verify the latter's applicability. Meanwhile, nonlinear simulation and parametric works with material damage plasticity models were also conducted for the static and fatigue failure mechanism understanding. The static and fatigue test results both showed that fractures at stud roots and surrounding local UHPC crushes were the main failure appearances. Compared with normally arranged studs, group arrangement could result in reductions of static stud shear stiffness, strength, and fatigue lives, which were about 18%, 12%, and 27%, respectively. Compared with the test results, stud shear capacity and fatigue lives evaluations based on the codes of AASHTO, Eurocode 4, JSCE and JTG D64 could be applicable in general while the safety redundancies tended to be smaller or even insufficient for group studs. The analysis results showed that arranging studs in groups caused obviously uneven strain distributions. The severer stress concentration and larger strain ranges caused the static and fatigue performance degradations of group studs. The research outcome provides a very important basis for establishing a design method of connections in the novel post-combination steel-UHPC composite deck.

BER Performance of an Offset Stacked Spreading CDMA System Based on Orthogonal Complementary Codes (직교 상보코드 기반의 옵셋누적 확산 CDMA 시스템의 비트오율 성능)

  • Kim, Myoung-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.3
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    • pp.1-8
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    • 2009
  • DS-CDMA system has very low bandwidth efficiency, hence it is difficult to maintain high spreading gain for high speed data transmission. Offset stacked spreading CDMA(OSS-CDMA) is a transmission scheme where spreading codes with chip offsets are overlapped, then transmitted. This kind of system requires a code set that guarantees orthogonality between codes in the set of any cjip offset. An orthogonal complementary code set has a property that the crosscorrelation function between codes in the group is zero for all shifts, hence it can be used for an OSS-CDMA system. In an OCC-OSS CDMA system each user is assigned an orthogonal complementary code group. User data bit is spread by the given codes and overlapped, and the code sequences are transmitted with multicarrier. However, the offset stacked spread sequences are multilevel, and the number of symbol levels is increases as the spreading efficiency is increased. When the OSS sequence is transmitted with MPSK mapping, the signal constellation becomes dense, and the system is easily affected by channel impairments. In this paper, we propose a level clipping scheme on OSS sequence before MPSK modulated. Simulations have been carried out to investigate the BER performance of the OCC-OSS CDMA system in AWGN environment. The results show that proposed scheme outperform the scheme without level clipping.

Comparing the performance of two hybrid deterministic/Monte Carlo transport codes in shielding calculations of a spent fuel storage cask

  • Lai, Po-Chen;Huang, Yu-Shiang;Sheu, Rong-Jiun
    • Nuclear Engineering and Technology
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    • v.51 no.8
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    • pp.2018-2025
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    • 2019
  • This study systematically compared two hybrid deterministic/Monte Carlo transport codes, ADVANTG/MCNP and MAVRIC, in solving a difficult shielding problem for a real-world spent fuel storage cask. Both hybrid codes were developed based on the consistent adjoint driven importance sampling (CADIS) methodology but with different implementations. The dose rate distributions on the cask surface were of primary interest and their predicted results were compared with each other and with a straightforward MCNP calculation as a baseline case. Forward-Weighted CADIS was applied for optimization toward uniform statistical uncertainties for all tallies on the cask surface. Both ADVANTG/MCNP and MAVRIC achieved substantial improvements in overall computational efficiencies, especially for gamma-ray transport. Compared with the continuous-energy ADVANTG/MCNP calculations, the coarse-group MAVRIC calculations underestimated the neutron dose rates on the cask's side surface by an approximate factor of two and slightly overestimated the dose rates on the cask's top and side surfaces for fuel gamma and hardware gamma sources because of the impact of multigroup approximation. The fine-group MAVRIC calculations improved to a certain extent and the addition of continuous-energy treatment to the Monte Carlo code in the latest MAVRIC sequence greatly reduced these discrepancies. For the two continuous-energy calculations of ADVANTG/MCNP and MAVRIC, a remaining difference of approximately 30% between the neutron dose rates on the cask's side surface resulted from inconsistent use of thermal scattering treatment of hydrogen in concrete.