• 한국통신학회논문지
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• 제34권3C호
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• pp.304-310
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• 2009

본 논문은 M-레벨 QAM 계층 변조 시스템에서 반복 수신기의 복잡도를 줄이기 위한 연속 MAP(maximum a posteriori probability) 검파 방식을 제안한다. 계층 변조 신호 내의 특정 우선 순위를 갖는 신호는 계층 변조 신호를 구성하는 각 신호를 우선 순위에 따라 간섭 신호 성분으로서 제거하거나 가우시안 잡음으로 간주한 후 MAP 방식에 의해 순차적으로 검파된다. 검파 과정을 순차적으로 진행함으로써 반복 수신의 복잡도를 신호 당 전송되는 비트 수에 선형적으로 증가하도록 감소시킬 수 있으며 각 부호화 비트의 연판정 값 계산 시 간섭 제거와 가우시안 가정의 효과를 검파 과정에 반영하여 잡음 분산을 조정함으로써 순차적 검파 방식에 의해 발생할 수 있는 성능 열화를 최소화한다. 전산 모의 실험을 통하여 제안하는 순차적 MAP 검파 방식의 성능이 최적 MAP 검파 방식과 비교하여 0.5dB 미만의 성능열화를 나타내는 것을 보인다.

• 융합신호처리학회논문지
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• 제12권4호
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• pp.322-332
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• 2011

본 논문에서는 한일공동VLBI상관기(Korea-Japan Joint VLBI Correlator, KJJVC)의 핵심 구성시스템인 VLBI상관서브 시스템(VLBI Correlation Subsystem, VCS) 본제품의 1차 성능시험에 대해 기술한다. VCS 본제품의 1차 성능시험의 주요 목적은 현장에 설치하기 전에 제작사에서 다양한 시험항목을 대상으로 시험을 수행하여 문제점을 확인 후 전체 시스템의 완성도를 높이는 것이다. 이번 성능시험에서는 VCS 시작품에서 발견된 FFT 재양자화의 유효비트 부족으로 인한 오버폴로어 문제점을 포함한 기능적인 시험을 수행하였다. 이번 VCS 본제품의 공장시험을 통하여 2008년 VCS 시작품의 성능시험에서 발견한 FFT 의 재양자화 문제점이 완전히 해결되었으며 VCS 본제품에 지연추적, 지연보상, 주파수 묶음 등의 중요 기능도 추가되었다. 그리고 실제 관측 데이터(광대역/협대역)를 이용한 상관처리 시험에서도 예측되는 상관결과가 출력되는 것을 확인하였다.

• 대한한방소아과학회지
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• 제30권2호
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• pp.72-81
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• 2016

Objectives The purpose of this study is to understand the correlation between spleen deficiency syndrome, body mass index (BMI) and eating habit in children and adolescents and to provide foundation of preventive care and treatment. Methods A survey was conducted with 115 children and adolescents, who were 4th, 5th and 6th grade of elementary school in Gwangju from March 2nd, 2016 to April 8th, 2016. Body mass index (BMI) was calculated using the measured height and weight. Spleen deficiency syndrome and eating habit in children and adolescents were investigated by using the Deficiency of the Spleen Questionnaire and Korean Children's Eating Behaviour Questionnaire (K-CEBQ). A data analysis was performed by using SPSS 23.0 program. Results 1. There was no statistically significant correlation between spleen deficiency syndrome and body mass index (BMI). 2. Children and adolescents with spleen deficiency syndrome were interested in food rather than avoided it. 3. There was a positive correlation between body mass index (BMI) and FR (Food responsiveness), "Food approach". The correlation between the healthy weight group and FR is statistically significant negative correlation. Conclusions Due to various limitations, it is difficult to generalize the correlation between spleen deficiency syndrome, body mass index (BMI) and eating habit in children and adolescents. Therefore additional research is necessary to confirm this study's findings.

• 한국치위생학회지
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• 제17권4호
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• pp.565-575
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• 2017

Objectives: This study aims to investigate patient cooperation for dental treatments by dividing patients into two groups with different treatment categories, i.e. orthodontic patients versus non-orthodontic patients. Methods: On December 2016, the study conducted survey targeting 311 orthodontic or non-orthodontic patients who are 20 years old or older living in Seoul and Gyeonggi-do, South Korea. The study subject were informed with the adequate information of the study and signed consent forms. Except for the questionnaire copies from 23 respondents whose answers were insincere those from 288 respondents, equivalent to 92.6% of the data collected, were used in the present analysis. Results: This review intended to clarify any factors affecting patient cooperation for dental treatments shows that the perception of oral condition, the reliability of dentistry, and the patient preventive cooperation had an effect on patient cooperation for dental treatments. Conclusions: The results summarized above suggest orthodontic patients who are familiar with dental treatments by virtue of their regular visits to dental clinics have higher cooperation for dental treatments compared to non-orthodontic patients, and the higher reliability of dentistry leads to higher patient cooperation for dental treatments.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.590-592
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• 1997

Making physical models of human body is not only time-consuming but also very expensive since they are usually hand-made. This problem is doubled with implant fabrication because an implant is almost always custom-made. Recently, RP is emerging as an alternative, and many RP applications are proposed in the medical field. The major advantage of this approach is due to a significant reduction of both time and cost required or the production. However, the technology is not much in practical use yet, especially in Korea. In this paper, we provide a method of generating STL files that are the standard format to RP machines. The original data are obtained from two-dimensional slices of MRI/CT machine. Example bone models have been produced using a commercially available RP machine, and the results are presented.

• 동의생리병리학회지
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• 제28권1호
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• pp.69-75
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• 2014

Osteoarthritis is a disease that has considerable effect on both individuals and economy. The number of osteoarthritis patients are gradually increasing as people get to enjoy longevity. This study was conducted to examine 30 osteoarthritis patients. Following is the report which shows the effectiveness of KJ27 based on statistical data analysis. Among 5 who have reported that they were not able to walk or use their knees at all, 80% of them were completely recovered. Among 18 who have stated that it was very hard for them to walk for more than a kilometer, 66.7% were completely recovered. Among 7 who have reported that it was little bit difficult for them to walk, 71.4% were completely recovered. Among 25 out of 30 who were very unsatisfied with former treatments, 70% of them stated that they were very satisfied with KJ27 treatments, and 30% of them stated that they were satisfied with it. Among 5 who had not had any type of osteoarthritis treatments, 100% have stated that they were very satisfied with the treatment. 18 patients who were under this treatment for a month were completely recovered; 10 patients who were under this treatment for 2 months were completely recovered; and finally 2 patients who were under this treatment for 3 months and longer were completely recovered. It is not clearly understood whether KJ27 will eradicate the entire symptoms of osteoarthritis, yet. Numerous case studies and experiments should be conducted to improve and apply KJ27.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.536-551
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• 2017

With the advancement and deployment of leading-edge telecommunication technologies for sensing and collecting, computing related information, Cloud of Things (CoTs) has emerged as a typical application platform that is envisioned to revolutionize the daily activities of human society, such as intelligent transportation, modern logistics, food safety, environmental monitoring, etc. To avoid any possible malicious attack and resource abuse, employing hash functions is widely recognized as one of the most effective approaches for CoTs to achieve message integrity and data authentication. The Whirlpool hash function has served as part of the joint ISO/IEC 10118-3 International Standard by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). In this paper, we propose an effective differential fault analysis on Whirlpool in the byte-oriented random fault model. The mathematical analysis and experimental results show that 8 random faults on average are required to obtain the current 512-bit message input of whirlpool and the secret key of HMAC-Whirlpool. Our work demonstrates that Whirlpool and HMAC-Whirlpool are both vulnerable to the single byte differential fault analysis. It provides a new reference for the security analysis of the same structure of the hash functions in the CoTs.

• 방송공학회논문지
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• 제7권1호
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• pp.55-65
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• 2002

웨이브렛 변환은 최근에 동영상 처리 분야에서 비정체적 동영상 신호를 나타낼 수 있기 때문에 많은 관심을 받고 있다. 대역 분할 방식의 웨이브렛 변환을 사용한 움직임 예측은 많은 곳에서 응용되어 지고 있으나 움직임 예측 오류가 최저 주파수 대역에서 발생하면 움직임 예측 오류는 다음 단계로 누적되고 각각의 단계에서 계산에 소요되는 시간과 데이터량이 증가하는 문제점을 가지고 있다. 다른 한편으로 왜곡율 관점에서 주어진 비트율에서 최고의 화질을 얻는 웨이브렛 패킷이 제안되었다. 그러나 이 방법에서 웨이브렛 패킷 설계를 위해 많은 시간이 소요되는 단점이 존재한다. 그래서 소요시간 문제를 해결하기 위해 Top-down 방식이 제시되었으나 주어진 비트율에서 최적의 해를 찾지는 못했다. 본 논문에서는 영상의 분산이 영상의 복잡도를 나타낼 수 있다는 것을 고려했다. 그래서 동영상 압축을 위한 적응적인 웨이브렛 패킷을 사용한 고속의 다해상도 움직임 예측 방법을 제안하였다.

• 한국의류학회지
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• 제27권9_10호
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• pp.1112-1123
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• 2003

This study is designed for improving wearing styles for middle-aged women who are in unsatisfactory body types and also providing the basic information about the suitable clothing designs for them. This study focuses on what kinds of body types they perceive, what the differences are between the perception of their body types and the real ones, and how the actual clothing styles can be affected by those perceived body types. This study is based on the survey of the perception of body types, the clothing styles, and the satisfaction level of body cathexis, while measuring body size of each person responded. The data were analyzed by Mean, ANOVA, Duncan-test of SPSS Win. (ver 10.1)program. The results are as follows: 1. The perception of their body types can be categorized into three clusters, the obesity, the arm & leg obesity, the slender. 2. By and large, Middle-aged women perceive their body types exactly what they we. However, they show a relatively subjective view on the upper arm girth, ankle girth, and arm length 3. The abdomen is at the lowest satisfactory part in body cathexis for the entire groups responded, and there are some differences among the perception of their body types in whole body silhouette and trunk. 4. Middle-aged women who perceive themselves as a bit slender show a tendency of having tight and revealing clothing styles, while the obese who perceived themselves wouldn't take them as appropriate dresses.

• 인터넷정보학회논문지
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• 제9권4호
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• pp.61-68
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• 2008

EPON(Ethernet Passive Optical Network: 이더넷 수동 광 네트워크)은 대용량 LAN과 백본망 사이의 트래픽 병목현상을 완화시킬 수 있는 하나의 방법으로 저렴한 비용으로 광대역의 서비스를 제공할 수 있어 많은 연구가 진행되고 있다. 대용량 LAN과 백본망 사이의 병목현상은 트래픽이 갑자기 증가는 트래픽 특성으로 인해 더욱 심각해진다. 본 논문은 트래픽의 특성을 고려하여 ONU(Optical Network Unit: 광 네트워크 가입자 단말)에게 적절한 대역폭을 할당함으로써 네트워크의 성능을 개선한다. 또한 본 논문은 지원하는 ONU의 수에 상관없이 고정된 시간 이내에 해당 ONU가 다시 서비스 받을 수 있도록 제안 방식을 설계함으로써 지연에 민감한 트래픽을 효율적으로 지원할 수 있다. 컴퓨터 시뮬레이션 결과에 따르면, 본 논문에서 제안하는 방식은 최대 사이클 시간을 기준 사이클 시간의 두 배로 제한하면서 기존 방식보다 중위 트래픽에서 패킷 지연 및 ONU 큐 크기를 각각 최대 77%와 82%만큼 감소시킨다.