• 한국시뮬레이션학회논문지
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• 제20권1호
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• pp.107-116
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• 2011

최근 가정 또는 사무실과 같은 실내 환경에서 음영지역을 해소하고 고품질의 서비스 제공을 위한 방안으로 초소형 기지국인 펨토셀(Femtocell)이 많은 관심을 받고 있다. 펨토셀은 사업자 및 사용자에게 다양한 이점을 제공하지만 펨토셀의 도입을 위해 서는 채널 선택에 따른 간섭제어, 네트워크 동기화, 자기 최적화 등 다양한 기술적 문제점이 해결되어야 한다. 이를 위해 본 연구에서는 펨토셀의 도입으로 인하여 발생 가능한 다양한 신호간섭 문제들에 대한 분석을 용이하게 하기 위한 LTE(Long Term Evolution) 시스템 기반 펨토셀 시뮬레이터를 개발하였다. 개발된 시뮬레이터는 단말 이동성, 스케줄러, 호 수락 제어, 트래픽 생성, MCS(Modulation and Coding Scheme) 결정의 5개의 블록과 이를 연결하고 관리하는 메인 모듈로 구성되어 있다. 또한 사용자의 편의성을 도모하기 위하여 시뮬레이션 결과를 실시간으로 관측할 수 있는 GUI(Graphical User Interface)를 적용하였다. 본 시뮬레이터는 실제와 유사한 환경에서 매크로셀과 펨토셀 사이의 간섭영향을 면밀히 분석하고 이동통신 시스템의 성능을 효과적으로 평가할 수 있도록 지원하며, 다양한 펨토셀 시스템을 개발하는데 크게 기여할 수 있을 것으로 예상된다.

• 한국통신학회논문지
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• 제28권3C호
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• pp.239-247
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• 2003

본 논문에서는 기존에 제안한 바 있는 EHC(Efficient Harmonic-CELP) 부호화기에 기반한 이중 전송률(2.4/4.0 kbps)의 개선된 하모닉-CELP(Improved Harmonic-CELP: IHC) 음성 부호화기를 제안한다. 제안된 IHC는 유/무성음 판별에 따라 유성음에서는 하모닉 추정, 하모닉 양자화, 하모닉 합성 및 잡음 혼합을 통한 자연성 제어 등의 과정을 통해, 무성음에서는 고속 CELP 방식을 통해 음성신호를 부호화/복호화한다. 또한 제안된 IHC는 EHC의 유/무성음 판별과 하모닉 추정 성능을 개선한다. 피치 이득과 에너지 등을 이용한 유/무성음 판별은 프레임 내의 에너지 변화 등에 의해 재판별된다. 하모닉 부호화에서는 첨점 추출과 델타 조정 방법을 이용하여 정확한 하모닉 추정을 하고, 혼합하는 잡음의 대역과 양을 적절하게 조절하여 자연성을 제어한다. 제안된 IHC 부호화기에 성능평가 결과, 비교 부호화기인 HVXC 연산량의 약 40%이내의 연산량으로 우수한 음질을 보임을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.867-869
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• 2012

FRUC(Frame Rate Up Conversion) 기법은 더욱 높은 품질의 단말기 또는 낮은 채널 전송율을 갖는 응용 시스템에서는 꼭 필요한 요소 기술이다. 본 논문에서는 이러한 응용분야를 위하여 양방향 대칭형 탐색에 기초한 FRUC 기법에서 생성된 움직임 보상 보간 프레임에 대하여 블록기반의 신뢰성을 평가하는 방법을 제안한다. 먼저 신뢰도를 측정할 수 있는 시간적 정합특성과 공간적 정합특성과 움직임 벡터의 균일성 분석을 통해 측정되는 비용함수를 도입하고, 비용 함수들의 조합을 통하여 실제 발생된 왜곡의 크기순과 매우 상관성이 높은 정렬 방식을 제안한다. 다양한 모의실험을 통하여 제안 방식은 높은 왜곡 블록을 찾는데 효과적임을 보인다. 또한, 제안방식은 FRUC기법과 더불어 분산 비디오 부호화 기술에도 효과적으로 활용될 수 있을 것으로 기대된다.

• 한국통신학회논문지
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• 제28권5C호
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• pp.548-554
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• 2003

서로 다른 음성 부호화기를 사용하는 유/무선 통신망의 연동에서 각 음성 패킷간 효율적인 변환 과정이 필요하다. 이러한 패킷 변환 가정을 위해서 과거에는 이중 부/복호화 방식을 이용하였다. 그러나, 두 음성 부호화기가 이중 부/복호화 방식으로 연동될 경우, 음질 저하 및 계산량 증가, 부가적인 전달 지연 등의 문제가 발생한다. 이 논문에서는 유/무선 통신 시스템에서 널리 사용되는 ITU-T G.723.1［1］과 TIA IS-127 EVRC(Enhanced-Variable-Rate-Codec)［2］음성부호화기 간의 효과적인 연동을 위한 상호부호화 알고리듬을 제안하였다. 제안된 상호부호화 알고리듬은 크게 LSP(Line-Spectrum-Pairs) 변환, 개회로 피치 변환, 고속 적응코드북 검색, 고속 고정코드북 검색의 네 부분으로 나뉘어 진다. TMS320C62x DSP를 사용하여 구현해 본 결과, 제안된 상호부호화 알고리듬이 기존의 이중 부/복호화 과정에 비해 30%∼35% 정도 계산량을 개선하며, 적은 지연 시간으로 동등한 주/객관적 음질을 제공함을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3123-3129
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• 2016

Background: Cancer is the fourth leading cause of death in Sabah Malaysia with a reported age-standardized incidence rate was 104.9 per 100,000 in 2007. The incidence rate depends on non-mandatory notification in the registry. Under-reporting will provide the false picture of cancer control program effectiveness. The present study was to evaluate the performance of the cancer registry system in terms of representativeness, data quality, simplicity, acceptability and timeliness and provision of recommendations for improvement. Materials and Methods: The evaluation was conducted among key informants in the National Cancer Registry (NCR) and reporting facilities from Feb-May 2012 and was based on US CDC guidelines. Representativeness was assessed by matching cancer case in the Health Information System (HIS) and state pathology records with those in NCR. Data quality was measured through case finding and re-abstracting of medical records by independent auditors. The re-abstracting portion comprised 15 data items. Self-administered questionnaires were used to assess simplicity and acceptability. Timeliness was measured from date of diagnosis to date of notification received and data dissemination. Results: Of 4613 cancer cases reported in HIS, 83.3% were matched with cancer registry. In the state pathology centre, 99.8% was notified to registry. Duplication of notification was 3%. Data completeness calculated for 104 samples was 63.4%. Registrars perceived simplicity in coding diagnosis as moderate. Notification process was moderately acceptable. Median duration of interval 1 was 5.7 months. Conclusions: The performances of registry's attributes are fairly positive in terms of simplicity, case reporting sensitivity, and predictive value positive. It is moderately acceptable, data completeness and inflexible. The usefulness of registry is the area of concern to achieve registry objectives. Timeliness of reporting is within international standard, whereas timeliness to data dissemination was longer up to 4 years. Integration between existing HIS and national registration department will improve data quality.

• 대한한방소아과학회지
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• 제33권4호
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• pp.74-88
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• 2019

Objectives The aim of this study is systematic evaluation of the quality of qualitative studies related to short stature. It will be utilized as fundamental data for future qualitative research about Korean Medicine Pediatrics treatment for short stature. Methods We searched qualitative studies related to short stature in the Pubmed. Two researchers independently assessed the quality of the qualitative researches by using Consolidated criteria for reporting qualitative research (COREQ) and Critical Appraisal Skills Program (CASP). We also qualitatively synthesized theme of each included studies. We presented integrated theme and categories with in vivo coding about qualitative research about short stature. Results A total of 47 papers were screened and 7 papers were finally selected. In the quality assessment using COREQ, detalied information about the researchers, methods of approach, reasons for non-participation, presence of non-participants, participant's review of the transcript, and participant's review of the findings were insufficient. In the quality evaluation using CASP, there were lack of justifications for the research methods, description method of research, and bias in process of data analysis. The findings were synthesized into three themes: fixed idea about height, discomfort caused by small stature and personal coping strategy with stress caused by short stature. Conclusions In further qualitative research, it is necessary to report the research according to COREQ and CASP checklist. It is also necessary to understand the stress and coping strategies to short stature of patients, We need to develop a social management strategy for short stature.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.87-91
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• 2009

Welding is one of the most important joining processes and the effect of welding residual stresses in the structure has a great deal of influence on its quality. In this paper, recent development in computational welding mechanics, particularly calculation of welding residual stresses, is introduced. The hypoelastic formulation of finite element analysis for thermoelastic-plastic deformation is applied to welding processes to find residual deformations and stresses. Leblond's phase evolution equation coupled with the energy equation is employed to calculate the phase volume fraction; this plays an important role as a kinetics parameter affecting phase fraction effects in the mechanical constitutive equation of welded materials. Furthermore, transformation plasticity is taken into account for an accurate evaluation of stress. The influence of the phase transformation and the transformation plasticity on residual stress is investigated by means of numerical analyses using metallurgical parameters in Leblond's phase evolution equation that are adjusted with respect to various cooling rates in a CCT-diagram. Coding implementation is conducted by way of the ABAQUS user subroutines, UMAT.

• 한국통신학회논문지
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• 제16권1호
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• pp.85-100
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• 1991

디지틀 이동 통신 시스템 검토에 있어서 고음질 저전송 속도의 음성 부호화기 연구는 가용 주파수 대역의 제한을 극복하여 통신 서비스를 증대시키기 위한 필수 사항의 하나이다. 본 논문에서는 디지특 이동 통신용 13 kbps RPE LTP 음성 부호화기의 구현에 관하여 다루었다. 하나의 DSP칩을 이용하여 양방향 통신방식으로 실시간 구현(DSP 로딩율 약 75%)이 가능함을 나타냈으며, 또한 H/W 구현을 위한 고정소수점 시뮬레이션 및 채널코딩과의 연계를 고려한 각 전송 파리미티의 비트 중요도 분석 결과를 제시하였다.

• 한국문헌정보학회지
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• 제23권
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• pp.127-163
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• 1992

The proper evaluation of reference services requires qualitative approach as well as quantitative one. The quality of a reference service can be evaluated by how promptly and accurately a librarian responds to the user's questions and also by how much the user is satisfied with the librarian's overall performance in providing the answer. In this study, the reference service of an university library was evaluated by the following procedure : 1. Identification of a group of the most frequently referred Korean government publications through two pre-tests of user surveys. 2. Preparation of 130 questions of bibliographic and factual type from the above publications. 3. Selection of 30 questions which can be answered from the collection of the evaluated library. 4. Mimic requests of reference service by 5 proxies trained on the unobtrusive test method with 30 questions asked at various times of the day and on various days of the week during a period of 5 months. 5. Drawing up of response sheets (by proxies) with descriptive comments on library staffs' question administration, response, attitude, etc. 6. Preparation and coding of data tabulation sheets and final analysis. The conclusions of this study are as follows : 1. The user serveys showed that needs for the library service for government publications were great. The $80\%$ of the government publications users were visiting more than two organizations for access to information and the $37\%$ were getting information directly from the publishers. 2. The librarians of the evaluated library could give correct answers to $53\%$ of 30 (bibliographic and factual) guestions. 3. The correctness of answer was independent of the length of the time spent the librarians. The librarians' grasp of the questions and direction of approach determined the success or failure of the service. 4. The librarians relied too much on the reference library catalog which doesn't include many of the government publications of their own collection. 5. The $79\%$ of the failure of the service were due to the librarians' lack of knowledge as to the information source for government publications and the unsystematic method of approach to it.

• Asian Pacific Journal of Cancer Prevention
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• 제17권6호
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• pp.2841-2846
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• 2016

Background: Tobacco use is the single most important preventable risk factor for cancer. Surveillance of tobacco-related cancers (TRC) is critical for monitoring trends and evaluating tobacco control programmes. We analysed the trends of TRC and evaluated the population-based cancer registry (PBCR) in Delhi for simplicity, comparability, validity, timeliness and representativeness. Materials and Methods: We interviewed key informants, observed registry processes and analysed the PBCR dataset for the period 1988-2009 using the 2009 TRC definition of the International Agency for Research on Cancer. We calculated the percentages of morphologically verified cancers, death certificate-only (DCO) cases, missing values of key variables and the time between cancer diagnosis and registration or publication for the year 2009. Results: The number of new cancer cases increased from 5,854 to 15,244 (160%) during 1988-2009. TRC constituted 58% of all cancers among men and 47% among women in 2009. The age-adjusted incidence rates of TRC per 100,000 population increased from 64.2 to 97.3 among men, and from 66.2 to 69.2 among women during 1988-2009. Data on all cancer cases presenting at all major government and private health facilities are actively collected by the PBCR staff using standard paper-based forms. Data abstraction and coding is conducted manually following ICD-10 classifications. Eighty per cent of cases were morphologically verified and 1% were identified by death certificate only. Less than 1% of key variables had missing values. The median time to registration and publishing was 13 and 32 months, respectively. Conclusions: The burden of TRC in Delhi is high and increasing. The Delhi PBCR is well organized and generates high-quality, representative data. However, data could be published earlier if paper-based data are replaced by electronic data abstraction.