• Title/Summary/Keyword: 비모수적 기법

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A Study of Relationship between Organizational Characteristics and the Usage Level of Quick Response Technologies (기업특성과 Quick Response Technologies의 사용 수준과의 관계 연구)

  • 고은주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.4
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    • pp.586-595
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    • 1996
  • 급변하는 국내외의 교역환경 변화에 따라 의류산업에도 새로운 경영 전략 수립이 요구되고 있다. Quick Response(QR)는 의류제품을 생산하는 기업의 경쟁력을 증가시키기 위해 소개된 새로운 경영 전략으로서, 유통 채녈 사이에 정보와 상품의 흐름을 효울화시켜 최대의 소비자 만족을 제공한다. 본 연구의 목적은 QR technologies의 사용현황을 밝히고 기업 특성과 QR technologies 사용수준과의 관계를 조사하였다. 종족변수는 QR technologies의 사용 수준이며, 선별된 독립변수들은 기업크기 (firm size), 기업전략 (organizational strategy), 제품종류(product category) , 패션변화(fashion change), 주기 적변화(seasonal change)였다. 조사대상은 미국 전역에서 무작위로 추출된 306개의 의류업체를 대상으로 하였으며, 1차 우편과 2차 전화로, 설문지를 통해 자료수집을 하였다. 설문 응답률은 47%(n=103)였고, 자료의 분석은 기술통계(i, e., 빈도, 퍼센트)와 비모수통계기법을 사용하였다. 가장 많이 사용되고 있는 QR technologies는 소량주문(small lot orders) , 단기 사이클 재단 계획 (short cycle cut planning)과 고객의 견이 반영 된 생산계획 (Production planning with customers)이였다. 가장 적게 사용되고 있는 QR technologies는 전자 재주문(electronic reorder)과 단위 생산 시스템 (unit production system)이 였다. QR technologies 사용수준에 관계가 있는 것은 기업크기 (firm size), 기업전략 (organizational strategy), 패션변화(fashion change) 임으로 나타났다. 의류업체의 크기가 클수록, 혁신적 선도기업 일수록, 패션변화가 큰 제품을 취급할수록 QR technologies의 사용수준이 높은 것으로 나타났다. 의류업체는 자원과 생산하는 제품종류에 따라 경영전략과 QR technologies의 사용수준이 다양하였다.

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Estimation of future probabilistic precipitation in urban watersheds and river flooding simulation considering IPCC Sixth Assessment Report (AR6) (IPCC 6차 평가 보고서(AR6)를 고려한 도시 유역 확률 강우량 산정과 하천 침수 모의)

  • Jun Seo Yoon;Im Gook Jung;Da Hong Kim;Jae Pil Cho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.88-88
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    • 2023
  • 지난 100년 동안 전 지구의 기상 이변이 꾸준히 증가하고 있다. 기후 변화는 도시 홍수 피해에 큰 영향을 끼치는데 급속한 도시화와 이상 기후로 인한 돌발 강우 패턴의 증가는 도시 침수의 취약성을 가중시킨다. 또한 급격한 도시 발전으로 인한 도심지의 불투수율 또한 꾸준히 증가하였다. 특히 2022년 8월 8일에 강남역과 도림천 일대에 내린 기록적인 강우는 기후 변화를 실감하게 하는 사회적 이슈가 되었으며 도심지 미래 수방 대책 변화를 상기시키는 계기가 되었다. 이로 인한 재해 피해에 최소화하기 위해 미래 기후 변화를 고려한 도심지의 새로운 방재 목표강우량 설정이 필요하다. 하지만 전 지구 모형(GCM)의 기후 변화 시나리오는 일 단위(Daily) 상세화 자료를 보편적으로 사용하고 있다. 하지만 이는 단기 강우 자료를 필요로 하는 도시 홍수 모의에서 제대로 활용할 수 없는 한계를 가지고 있다. 따라서 본 연구는 2019년에 발간된 IPCC 6차 평가 보고서(AR6)가 제안하는 SSP(Shared Socioeconomic Pathways, 공통사회경제경로) 시나리오를 기반하여 상세화된 일 단위(Daily) 강우 데이터를 비모수적 통계 기법을 사용하여 시간 단위(Hourly)로 상세화하였다. 또한 지속 시간별 연 최대치 강우를 추출하여 빈도 해석을 통해 도시 유역의 미래 확률 강우량을 제시하였으며, 서울시 상습적인 침수 취약 지역인 도림천 유역에 강우-유출 모형(XP-SWMM)을 사용하여 미래전망 기후 자료인 SSP2-4.5와 SSP5-8.5에 따른 미래 확률 강우 침수 모의를 실시하였다. 본 연구의 결과는 최신 기후 변화 시나리오를 고려한 서울시 방재 성능 목표 강우량 산정에 활용 가능할 것으로 사료되며 미래 강우량 침수 모의를 통해 침수 취약 구역인 도림천 일대 홍수피해의 근거 자료가 되는 것에 의의를 둔다. 또한 치수 분야에서 기후 변화를 고려하기 위해서는 기후 변화 시나리오에 따른 시간 단위 자료의 상세화가 필요함을 시사한다.

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Measuring Relative Efficiency of Korean and Japanese Construction Firms Using Data Envelopment Analysis (자료포락분석을 이용한 한국과 일본 건설기업의 상대적 효율성 분석)

  • Choi, Jae-Kyu
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.2
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    • pp.217-226
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    • 2015
  • The aim of this study is to compare relative efficiency Korean and Japanese construction firms over the period of 2000-2013, and to analysis relative efficiency using Data Envelopment Analysis (DEA). This study employs DEA in analyzing of 7 Korean construction firms and 8 Japanese construction firms using 2 input and 1 output variables. The efficiency results of this study is temporarily lowered due to IT Bubble Decay and Global Financial Crisis. The efficiency of Korean construction firms from 2000-2001 is lower Japanese construction firms, but the efficiency of Korean construction firms from 2002-2013 is higher Japanese construction firms. These results mean that the management of Korean construction firms were operating more efficiently than Japanese construction firms.

A Crash Prediction Model for Expressways Using Genetic Programming (유전자 프로그래밍을 이용한 고속도로 사고예측모형)

  • Kwak, Ho-Chan;Kim, Dong-Kyu;Kho, Seung-Young;Lee, Chungwon
    • Journal of Korean Society of Transportation
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    • v.32 no.4
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    • pp.369-379
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    • 2014
  • The Statistical regression model has been used to construct crash prediction models, despite its limitations in assuming data distribution and functional form. In response to the limitations associated with the statistical regression models, a few studies based on non-parametric methods such as neural networks have been proposed to develop crash prediction models. However, these models have a major limitation in that they work as black boxes, and therefore cannot be directly used to identify the relationships between crash frequency and crash factors. A genetic programming model can find a solution to a problem without any specified assumptions and remove the black box effect. Hence, this paper investigates the application of the genetic programming technique to develope the crash prediction model. The data collected from the Gyeongbu expressway during the past three years (2010-2012), were separated into straight and curve sections. The random forest technique was applied to select the important variables that affect crash occurrence. The genetic programming model was developed based on the variables that were selected by the random forest. To test the goodness of fit of the genetic programming model, the RMSE of each model was compared to that of the negative binomial regression model. The test results indicate that the goodness of fit of the genetic programming models is superior to that of the negative binomial models.

The Competitiveness Improvement Scheme of Academic Libraries through the Comparison of their Principal Indicators (관종별 도서관의 주요지표 비교를 통한 대학도서관 경쟁력 제고 방안)

  • Park, Il-Jong
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.20 no.3
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    • pp.13-31
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    • 2009
  • The major indicating data of academic, public, and school libraries which were mentioned in the Korea library yearbook 1998 through 2007 were collected for this study. The results were analyzed and the methods that may be applied to a library management were presented in this paper. The collected data were analyzed by using the MS-excel and SPSS. The numbers of libraries, personnels, collections and their used ones, users, management budget were used for the variables of this study, and the correlation coefficients and non-parametric method etc. were used for the variable analysis. The results show that public and school libraries are growing consistently, but academic ones get stagnant currently.

The influence of tax credit on firm's innovation performance (조세감면이 기업의 R&D혁신성과에 미치는 영향)

  • Choi, Seok-Joon;Seo, Young-Woong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3223-3231
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    • 2010
  • For a long time, most of advanced countries have supported the innovative firms with various support methods such as tax credit, subsidy, human resource education, and so on. Tax credit for innovation is the most popular industrial policy in these countries including Korea. However, in Korea, the effect of tax credit policy has been rarely analyzed. On the other hand, a considerable number of studies discover that tax credit policy in other countries influences positively on invest of R&D expenditure. This paper shows that tax credit policy positively influences on firm's innovation performances in Korea. The evaluated innovative effect of tax credit policy in this paper is more persuasive because it introduces various innovation performance variables including patent application with Propensity score matching method(PSM).

An Inference Method of a Multi-server Queue using Arrival and Departure Times (도착 및 이탈시점을 이용한 다중서버 대기행렬 추론)

  • Park, Jinsoo
    • Journal of the Korea Society for Simulation
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    • v.25 no.3
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    • pp.117-123
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    • 2016
  • This paper presents inference methods for inner operations of a multi-server queue when historical data are limited or system observation is restricted. In a queueing system analysis, autocorrelated arrival and service processes increase the complexity of modeling. Accordingly, numerous analysis methods have been developed. In this paper, we introduce an inference method for specific situations when external observations exhibit autocorrelated structure and and observations of internal operations are difficult. We release an assumption of the previous method and provide lemma and theorem to guarantee the correctness of our proposed inference method. Using only external observations, our proposed method deduces the internal operation of a multi-server queue via non-parametric approach even when the service times are autocorrelated. The main internal inference measures are waiting times and service times of respective customers. We provide some numerical results to verify that our method performs as intended.

A code acquisition method using signed-rank statistics in frequency-selective channels (주파수선택적 감쇄 채널에서 부호순위 통계량을 쓴 부호 획득 방법)

  • Kim, Hong-Gil;Jeong, Chang-Yong;Song, Ik-Ho;Gwon, Hyeong-Mun;Kim, Yong-Seok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.2
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    • pp.69-80
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    • 2002
  • In this paper, signed-rank based nonparametric detectors are used for direct sequence code division multiple access pseudo-noise code acquisition systems in frequency-selective Rician fading channels. We first derive the locally optimum rank detector, and then propose the locally suboptimum rank (LSR) and k-th order modified signed-rank (MSRk) detectors using approximate score functions. We compare the serial and hybrid parallel double-dwell schemes using the LSR and MSRk detectors with those using the conventional squared-sum (SS) using the cell averaging constant false alarm rate processor and modified sign detectors. From the simulation results, it is shown that the LSR and MSRk detectors perform better than the SS detector using the cell averaging constant false alarm rate processor.

Analysis of Air-water Temperature Elasticity Taking into Account the Confidence Interval in Major Tributary of Nakdong River (낙동강 주요 지류의 신뢰구간을 고려한 기온-수온 탄성도 분석)

  • Park, Jaebeom;Kal, Byungseok;Kim, Seongmin
    • Journal of Wetlands Research
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    • v.22 no.3
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    • pp.178-186
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    • 2020
  • In this study, the elasticity was calculated and sensitivity analysis was performed using air-water temperature data of the major tributaries of the Nakdong River. We developed a nonparametric elasticity analysis technique capable of estimating the confidence interval for elasticity and verifying the hypothesis, and examined its applicability compared to the existing method using the median value. It is analyzed that the elasticity of winter is low and the elasticity of summer and autumn is high, so that the fluctuation of water temperature and water quality according to the fluctuation of air temperature is large. The spatial elasticity tends to be low in the Geumho River area, which is influenced by artificial factors such as sewage treatment plant effluent, small and medium-sized livestock wastewater, and small-scale factory wastewater. Since the elasticity of major tributaries of the Nakdong River is over weak and is reasonable at a significance level of 5%, it was analyzed that the air-water temperature fluctuation caused by climate changes is large.

Confidence Interval Estimation of the Earthquake Magnitude for Seismic Design using the KMA Earthquake Data (기상청 지진 자료를 이용한 내진설계 지진규모의 신뢰구간 추정)

  • Cho, Hong Yeon;Lee, Gi-Seop
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.1
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    • pp.62-66
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    • 2017
  • The interest on the potential earthquake magnitude and the request on the earthquake-resistant design examination for coastal structures are emerged because of the recently occurred magnitude 5.8 earthquake in Gyeoung-Ju, Korea. In this study, the magnitude and its confidence intervals with the return periods are estimated using the KMA earthquake magnitude data (over 3.5 and 4.0 in magnitude) by the non-parametric extreme value analysis. In case of using the "over 4.0" data set, the estimated magnitudes on the 50- and 100-years return periods are 5.81 and 5.94, respectively. Their 90% confidence intervals are estimated to be 5.52-6.11, 5.62-6.29, respectively. Even though the estimated magnitudes have limitations not considering the spatial distribution, it can be used to check the stability of the diverse coastal structures in the perspective of the life design because the potential magnitude and its confidence intervals in Korea are estimated based on the available 38-years data by the extreme value analysis.