• 산업공학
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• 제18권4호
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• pp.382-389
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• 2005

Location management is very important issue in wireless communication system to trace mobile users' exact location. In this study, we propose a dynamic location area management scheme which determines the size of dynamic location area considering each user's characteristics. In determining the optimal location area size, we consider the measurement data as well as the historical data, which contains call arrival rate and average speed of each mobile user. In this mixture of data, the weight of historical data is derived by linear searching method which guarantees the minimal cost of location management. We also introduce the regularity index which can be calculated by using the autocorrelation of historical data itself. Statistical validation shows that the regularity index is the same as the weight of measurement data. As a result, the regularity index is utilized to incorporate the historical data into the measurement data. By applying the proposed scheme, the location management cost is shown to decrease. Numerical examples illustrate such an aspect of the proposed scheme.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.119-126
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• 2004

Location management is very important issue in wireless communication system to trace mobile users' exact location. In this study, we propose a dynamic location area management scheme which determines the size of dynamic location area considering each user's characteristic. In determining the optimal location area size, we consider the measurement data as well as the historical data, which contains call arrival rate and average speed of each mobile user. In this mixture of data, the weight of historical data is derived by linear searching method which guarantees the minimal cost of location management. We also introduce the regularity index which can be calculated by using the autocorrelation of historical data itself. Statistical validation shows that the regularity index is the same as the weight of measurement data. As a result, the regularity index is utilized to incorporate the historical data into the measurement data. By applying the proposed scheme, the location management cost is shown to decrease. Numerical examples illustrate such an aspect of the proposed scheme.

• 대한교통학회지
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• 제26권5호
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• pp.131-141
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• 2008

고속도로에서의 지점검지체계로부터 수집 가공 처리된 과거 통행시간 이력자료를 이용한 통행시간 예측시, 사용되는 대표값과 과거 데이터량에 따라 예측의 정확성이 결정되나 이에 대한 체계적인 연구가 없는 실정이다. 따라서 본 연구의 목적은 신뢰성 있는 통행시간 예측을 위해 통행시간 이력자료의 적정 대표간과 과거 데이터량을 결정하기 위한 방법론을 제시하였다. 과거 통행시간 이력자료의 적정 대표값은 예측오차의 평균이 가장 적은 대표값을 선정할 수 있으며, 적정 과거 데이터량은 비슷한 속성을 가진 과거 통행시간 이력자료의 개별간의 차이 또는 집단 간의 차이를 최소화하는 CVMSE(Cross Validated Mean Square Error)방법을 이용하여 결정할 수 있다. 한국도로공사의 고속도로 지점검지기 자료에 적용한 결과, 적절 대표값은 중앙값으로 분석되었으며, 통행시간 예측을 위한 적정 과거 데이터량은 60일로 분석되었다.

• 한국ITS학회 논문지
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• 제11권6호
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• pp.40-48
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• 2012

교통정보센터는 통행속도 정보를 수집하여 사용자에게 제공한 후, 이력자료를 데이터베이스에 저장하여 관리하고 있다. 통행속도 이력자료를 이용하여 통행속도를 예측할 때 사용되는 대푯값과 과거 데이터량에 따라 통행속도 예측 정확도가 다르게 나타나나, 이에 대한 체계적인 연구가 부족한 실정이다. 본 연구에서 신뢰성 있는 통행속도 예측을 위해 통행속도 이력자료의 적정 대푯값과 과거 데이터량을 결정하기 위한 방법을 제안하였다. 제안된 방법의 평가를 위해, 서울시 4개 도로구간의 최근 1년간 화요일(평일) 및 일요일(공휴일) 통행속도 이력자료를 수집하여 현장실험을 실시하였다. 실험결과 통행속도 예측을 위한 적정 대푯값은 평균값 및 가중평균값으로 분석되었으며, 통행속도 예측을 위한 적정 과거 데이터량은 2개월로 나타났다.

• 대한토목학회논문집
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• 제33권4호
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• pp.1707-1718
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• 2013

실적공사비 제도는 2004년부터 도입된 제도로서, 과거의 유사 공사의 계약단가를 토대로 공종별 단가를 파악하여 예정가격을 결정하는 방식이다. 이러한 실적공사비 단가는 매년 2회 한국건설기술연구원에서 발표하고 있다. 소규모 공사의 공사비 단가는 작업단위당 생산비용 증가, 장비 및 노무비 등 상승으로 인해 대규모 공사보다 높을 수밖에 없는 것이 건설공사의 특성이다. 그러나 실적공사비 단가가 공사의 규모와 무관하게 일률적으로 적용되고 있어 문제점으로 대두되고 있다. 본 연구에서는 이러한 실적공사비 제도의 문제점을 파악하기 위해서 대 소규모 토목공사의 실적공사비를 비교 분석하였으며, 소규모 토목공사의 실적공사비가 대규모 토목공사에 비해 21.8% 높은 결과가 도출되었다.

• 한국의상디자인학회지
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• 제2권2호
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• pp.113-136
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• 2000

Problems and improvemental measures for the historical inquiry of TV drama costumes and for the reproduction of them were investigated. For this study, the MBC historical drama 'The way of the Great King' started on march 24 in 1998 and ended on september 26 in 1998 was selected as the subject. The reasons why the drama was selected are as follows. First, the historical background was the time of King Young ＆ drama introduced various kinds of costumes Joungjo, which is the starting era of traditional costumes peculiar to Korea. Second, the based on the historical inquiry of that time. There is a limitation in the process of historical inquiry about the costumes of that time because we don't have enough research data such as relics, remains, references, literary works, pictures, etc. Although, in some cases, exact historical inquiry about the costumes were made, they could not be reproduced in the original forms due to several reasons: the absence of the materials of that time, structural changes including length and size for convenience of action, alterations of the manufacturing method for the reuse, addition of the gorgeous and various olors for the enhancement of image quality, variations in colors according to the actor's character, modulations of the structures and colors by the producer's intention, and the restraints in time and money for manufacturing. In view of these situations, it seems to be difficult for us to settle the problems occurring between the historical inquiry about the traditional costumes and the reproduction of them in drama. However, the costumes presented in historical drama have the meanings to provide informations of that time with TV audience. Therefore I think that it is necessary to narrow the gap between the historical inquiry of TV drama costumes and for the reproduction of hem, First, It should be restrained that each broadcasting stations show the costumes under the similar situations of the same age in different ways. Second, We need to unify the inquiry systems concerning historical drama costumes, In addition to this, it is also necessary for broadcasting stations to establish internet sites of traditional costumes for communication.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 1997년도 제12회 동계학술발표회 논문집
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• pp.177-196
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• 1997

The engineering industry plays an important role for national competitive, since it has an high impact on other industries. With its importance, the engineering industry development largely depends on its technical manpower ather than capital factor. This study aims at estimating the additional requirement on technical manpower based on the forecasted market size which represents the structure change corresponding to economic growth in related industry. Research scope includes the twelve of fifteen field except three with insufficient historical data and technical manpower above bachelor degree. Specialty, we forecast market size with determinants resulted from historical data analysis on each field. The demand on technical manpower is derived from the forecasted market. We also estimate an additional requirement with the supply analysis. The research results show different patterns over time period. The relative ratio on chemical and construction to total market will steadily grow over short term, while applied, environment, electronic and information will rapidly grow This pattern will be stabilized over mid or long term. The additional requirement on technical manpower represents the similar pattern to market growth. The research result implies manpower policy for having high inflow of technical engineer from educational institute and the related industries through the image improvement.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.210-217
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• 1999

Chemical oxygen demand (COD), phytoplankton cell number and chlorophyll-a concentration (Chl-a), sediment mean grain size and ignition loss were studied to determine their temporal trends in the study area. Historical data of COD, cell number and Chl-a were gathered from the late 1960s or early 1980s to 1997, and trends in temporal domain were obtained from a simple regression. Sediments for grain size and ignition loss (as organic contents in sediments) were sampled from the Chokchon macrotidal flat bimonthly from September 1990 to November 1996, and were analyzed using the decomposition method of time series analysis. In general, the first three data showed increasing trends based on regression analysis. The trends of sediment grain size fluctuated in a neutral pathway while those of ignition loss yielded no increasing pattern. In contrast with the suggestions from Ahn and Choi (1998) who reported a coarsening variation in sediment grain size to be a cause of the directional and remarkable changes of macrofaunal communities in this area, we could not find such a corresponding variation pattern from our samples. In diagnosing eutrophication, a paradoxical phenomenon was encountered between the trends in water column (COD, cell number and Chl-a) and sediment (ignition loss) data. In this paper, we inferred the possible processes that produce the discrepancy. Some explanations and biological responses to eutrophication were predicted and discussed.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.64-71
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• 1999

Seismicity of the Korean Peninsula shows intraplate seismicity that has irregular pattern in both time and space. Seismic data of the Korean peninsula consists of historical earthquakes and instrumental earthquakes. In this study we devide these data into complete part and incomplete part and considering earthquake size uncertainty estimate seismic hazard parameters - activity rate λ, b value of Gutenberg-Richter relation and maximum possible earthquake IMAX by statistical method in each major tectonic provinces. These estimated values are expected to be important input parameters in probabilistic seismic hazard analysis and evaluation of design earthquake.

• 한국도서관정보학회지
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• 제34권4호
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• pp.271-289
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• 2003

역사적으로 한국사회의 문자ㆍ도서관이용자를 이해하기 위하여 문화변용이론과 랑가나단의 이론을 적용하고, 이용자의 통계를 수집하여 시계열분석 한 결과 고대에는 혈통이나 상업, 종교, 고려와 조선에서는 사회계층이 문자ㆍ도서관 이용에 영향을 미쳤다. 현대에는 도서관의 장서량과 증가책수, 예산, 국가의 정보정책과 도서관이용자수가 관계가 있다.