• 대한전자공학회논문지TC
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• 제38권3호
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• pp.1-8
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• 2001

DS/CDMA방식의 이동통신 시스템에서 다중접속 및 다중경로 페이딩 간섭을 제거하기 위하여 비교적 구조가 간단한 병렬 간섭제거기가 이용된다. 다단계로 구성되는 병렬 간섭제거방식에서 다중접속 간섭의 제거 성능을 향상시키기 위하여 간섭의 정확한 추정이 필수적이다. 본 논문에서는 제거성능의 향상을 위해 NLMS(Normalized Least Mean Square)알고리즘으로 가중치(weight)를 계산하는 적응 제거방식과 시험 검파기로서 HT(Hyperbolic Tangent)검파방식에 NZ(Null Zone)을 이용하는 새로운 검파방식을 제안하고 모의실험을 통하여 그 성능을 분석하였다. 모의실험 결과 제안하는 방식이 비트오율 $2{\times}10^{-2}$에서 기존의 제거기에 비해 사용자수가 약 48%정도 증가하는 개선된 성능을 얻었다.

• 한국통신학회논문지
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• 제29권7A호
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• pp.836-843
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• 2004

본 논문에서는 고속 TDMA (Time Division Multiple Access) 위성 통신 시스템에 적합한 위상 동기 방식을 제시하고, 추적 성능을 평가하였다. 낮은 SNR에서 작동하고 초기 포착 특성이 우수한 방식을 사용해야 하는 위성통신 시스템에 있어 채널 코딩은 필수적이다. 따라서 코딩에 적합한 위상 동기 방식이 필요하다. 그러나 기존의 DD (Decision Directed)나 NDA (Non-Data-Aided) 방식은 낮은 SNR에서 cyclic slipping 과 Hangup 현상에 민감하기 때문에 코딩 이득을 제대로 얻을 수 없다. 이러한 현상을 보완하기 위해 TD (Tentative Decision) 방식과 PSP (Per Survivor Processing) 방식이 제안되었다. PSP 방식은 TD 방식에 비해 성능이 뛰어나기는 하지만 복잡도가 크다는 단점을 가지고 있다. 따라서 본 논문에서는 채널 상태에 따라 적응적으로 PSP 방식과 TD 방식을 결합하여, 복잡도 문제를 해결하고 PSP 방식의 성능에 근접하는 ARSE (Adaptive Reduced State Estimator) 방식을 제안하였다.

• Asia pacific journal of information systems
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• 제4권1호
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• pp.74-114
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• 1994

In spite of the importance of group decision making in corporations and recent active research efforts in group decision support systems in the US., few studies have been done in the area of group decision making in Korea. There is an urgent need to understand the behavior and peculiar characteristics of group decision making in Korea before we initiate any research in developing computer systems to help group decision making. This study proposes a model for group decision making based on the literature survey and empirical studies have been conducted using the model Although this study is exploratory in nature, tentative hypotheses are given for future research in group decision making.

• 한국경영과학회지
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• 제10권1호
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• pp.79-83
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• 1985

This purpose of this study is to suggest a tentative model for project selection of information system. In constructing a mathematical model, quantification of decision criteria is tried to lessen difficulties of measuring benefits of information system project. Suggested model enables us to select projects in the context of portfolio and information system policy.

• 한국농공학회지
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• 제35권4호
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• pp.86-94
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• 1993

In this study, a tentative decision-making matrix for village planning in reclaimed land was proposed. The evaluating conditions in the matrix are reclaimed farming acreage and distance. And the indexes for evaluation works are farming acreage required for increasing present farm size to target size in the base of, allowable commuting distance for farming from and effective controlling distance of each village. The village planning strategies are considered into four categories ; upkeep of present village scale, transfer of its superfluous farming acreage to a neighbouring village, enlargement of present village scale and new village construction in reclaimed land. As a case study, the proposed decision-making matrix was applied to 69 villages, which are contiguous to the potential farming area from reclamation works of Yongsan River Basin Comprehensive Development Project Phase Ill and so considered in this study as future farming villages there. From the application results, the following tactics for village planning may be proposed ; principally, upkeep or enlargement of present village scale, but, in an exceptional few cases of standard farming size being 3~5ha, new village construction of normal or satellite scale.

• 대한임베디드공학회논문지
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• 제9권5호
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• pp.285-292
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• 2014

The commonly used Newton-Raphson's floating-point number divider algorithm performs two multiplications in one iteration. In this paper, a tentative K'th Newton-Raphson's floating-point number divider algorithm which performs K times multiplications in one iteration is proposed. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications per an operation in single precision and double precision divider is derived from many reciprocal tables with varying sizes. In addition, an error correction algorithm, which consists of one multiplication and a decision, to get exact result in divider is proposed. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a floating point number divider unit. Also, it can be used to construct optimized approximate reciprocal tables.

• 한국통신학회논문지
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• 제25권11A호
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• pp.1652-1660
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• 2000

본 논문에서는 DS/CDMA (Direct Sequence/Code Division Multipe Access) 시스템에서 임시 판정 함수로서 연판정 함수와 경판정 함수를 적용한 파이프라인화된 직렬 간섭 제어 구조(PSIC, Pipelined Successive Interference Cancellation)의 성능을 수식적으로 분석하고, 모의 실험을 통하여 검증한다. PSIC 구조는 다단 직렬 간섭 제거 구조(MSIC, Multistage Successive Interference Cancellation)가 가지는 복호지연(decoding delay)의 문제를 해결하기 위해 파이프라인 구조를 MSIC에 적용한 것이다. 제안된PSIC 구조는 하드웨어의 복잡도(hardwar complexity)를 희생하여 비트 오율(BER, Bit Error Rate)의 증가 없이 MSIC에서 발생하는 복호 지연을 줄일 수 있다. 또한 제안된 PSIC 구조에서 연판정 함수와 경판정 함수를 각 간섭 제거 단(Cancellation stage)에서의 임시 판정 함수로 사용하여 얻게 되는 PSIC 구조들의 성능을 비교한다. 분석 및 실험 결과에 의하면 제안되 PSIC 구조에서는 경판정 함수를 사용할때의 성능이 연판정 함수를 사용할때의 성능보다 우수함을 알 수 있었다.

• 한국통신학회논문지
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• 제26권9A호
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• pp.1492-1498
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• 2001

DS-CDMA 시스템에서 다중 사용자간섭에 의한 성능 저하를 방지하기 위하여 비교적 구조가 간단하고, 성능이 우수한 병렬 간섭제거기가 이용된다. 본 논문에서는 병렬간섭제거기에 이용되는 기존 검파기의 파라미터의 최적화를 통하여 적응 병렬간섭제거기의 성능을 분석하고, 새로운 시험검파기인 HTNZ 검파방식을 제안한다. 적응 병렬간섭제거기는 기존의 부분 병렬간섭제거기에서 사용하는 고정된 값의 가중치를 NLMS 적응 알고리즘을 이용하여 적응적으로 계산하는 방법을 사용하였다. 시뮬레이션 결과 제안하는 방법이 기존의 hard 검파방식에 비해 사용자 용량이 57% 증가하는 향상된 결과를 얻었다.

• 동의생리병리학회지
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• 제21권1호
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• pp.347-351
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• 2007

This study was done to report the improvement of second case report form(CRF) and standard operating procedure(SOP) of Tentative Korean Standard Differentiation of the Symptoms and Signs for Stroke. We were in charge of developing case report form(CRF) and educating the investigators. In the process of this project, we needed to develop standard operating procedure(SOP) for this CRF. So we made Tentative Korean Standard Differentiation of the Symptoms and Signs for Stroke and tried clinical application at Department of Oriental Internal Medicine of Wonkwang University and Daejeon University in 2005. And in this pilot study we can find out some problems and need to improve it. We strengthen the incision and exclusion criteria of CRF We canceled the Chief complains entry for efficiency. We reflected the decision of Stroke standard committee. We reduced the differentiation index of CRF to promote efficiency and accuracy. We rearranged the order of the differentiation index to promote rationality and practicality. We regulated detail item belonging to Differentiation index. We used a colloquialism in question. We inserted flow chart in SOP. We inserted picture of diagnostic index.

• 농촌계획
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• 제4권1호
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• pp.98-107
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• 1998

For efficient development of rural facilities, choice of their optimum locations would be an important issue, however, existing research works concentrated much more an allocation policy of urban industrial complex and public facilities than rural ones. In this study, because agricultural-cum-industrial complex has been the most widely developed representative one of rural facilities, it was selected as a case study facility. As a pre-study to system development, existing governmental location-decision system was checked and interviewing survey carried out to find out on-spot problems. And, being based on literature review and survey analysis results, 4-step optimum locational decision model was developed , formulation of locational goal system, ranking tabulation on components, determination of significance values of components, calculation of component scores. Finally, through the case study works on 3 sites, system applicability was checked, Considering together the simplicity problem of existing guidelines and the interviewing survey results favoring the diversified viewpoints, it would be necessary to develop multifaceted support system for locational decision making. 3-tier classification steps from the higher, middle to lower one were used and their underpinning viewpoints were sorted as on regional development, entrepreneurship, spatial rationality, from which a tentative locational goal system was formulated. Through the expert group checking, final locational goal system was determined having 3 of the higher classification items, 7 of the middle ones, 23 of the lower ogles. For ranking tabulation, 3 types of ranking criteria were arranged which were based on statistical analysis using mean and standard deviation(Type I ), its existence or not 1 good or not(Type E ), and the others(Type E ). From the significance evaluation results, regional development and entrepreneurship aspects were valued much higher than spatial rationality aspect. And, in the middle step, items as spread effects of regional economy, accessibility and social potentialities were highly valued while infrastructural development level and natural condition being low. The application results of the system to 3 case study total. However, the detailed ones differed among study the influencing effects on regional economy, and contrast greater the infrastructural development level. Conclusively, final evaluation values well represented the characteristics of each area. If this system be complemented and applied comprehensively by the successive studies, it would be developed to a general model of locational decision supporting system for rural facilities.