• Title/Summary/Keyword: problem analysis

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Development of Fire Weather Index Model in Inaccessible Areas using MOD14 Fire Product and 5km-resolution Meteorological Data (MODIS Fire Spot 정보와 5km 기상 재분석 자료를 활용한 접근불능지역의 산불기상위험지수 산출 모형 개발)

  • WON, Myoung-Soo;JANG, Keun-Chang;YOON, Suk-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.189-204
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    • 2018
  • This study has developed a forest fire occurrence probability model for inaccessible areas such as North Korea and Demilitarized Zone and we have developed a real-time forest fire danger rating system that can be used in fire-related works. There are limitations on the research that it is impossible to conduct site investigation for data acquisition and verification for forest fire weather index model and system development. To solve this problem, we estimated the fire spots in the areas where access is impossible by using MODIS satellite data with scientific basis. Using the past meteorological reanalysis data(5㎞ resolution) produced by the Korea Meteorological Administration(KMA) on the extracted fires, the meteorological characteristics of the fires were extracted and made database. The meteorological factors extracted from the forest fire ignition points in the inaccessible areas are statistically correlated with the forest fire occurrence and the weather factors and the logistic regression model that can estimate the forest fires occurrence(fires 1 and non-fores 0). And used to calculate the forest fire weather index(FWI). The results of the statistical analysis show that the logistic models(p<0.01) strongly depends on maximum temperature, minimum relative humidity, effective humidity and average wind speed. The logistic regression model constructed in this study showed a relatively high accuracy of 66%. These findings may be beneficial to the policy makers in Republic of Korea(ROK) and Democratic People's Republic of Korea(DPRK) for the prevention of forest fires.

A Study on the SCM Integration & Green Growth Strategy of Logistic Company in Korea (물류기업의 SCM통합과 녹색성장을 위한 대응방안에 대한 연구)

  • Jin, Yun-Jun;Lee, Yu-Bin;Bae, Ki-Hyung
    • International Commerce and Information Review
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    • v.15 no.2
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    • pp.3-23
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    • 2013
  • In 1997, 180 countries signed the Kyoto Protocol in Kyoto, Japan. The Kyoto Protocol came into force in February 2005. The agreement calls for industrialized nations to cut greenhouse gas emissions by 5 percent from 1990 levels by 2008 to 2012. One of those polices is a modal shift that change from road freight to sea, inland waterway and railroad transportation that is eco-friendly. The increase of road freight brings road congestion, accidents, logistic costs, air pollution and greenhouse gases. Railroads are superior than the other modes of transportation in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. Korean railroads were used by passengers and freight transport popularly until the middle of 20th century, however, by the sudden change of logistics environments, a shaving time efficiency being most important, railroad logistic lost its competitive power against the transportation by truck. From the research which sees consequently investigated a various policy, a system and a law about Chinese logistics industry and present condition of the Chinese goods enterprise and instance analysis of the large Chinese corporation that branch out to undeveloped markets led and a Chinese logistics industry and problem point escape hereafter the heightening of competitiveness plan which is rational under prsenting boil.

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Analysis on the Temperature of Multi-core Processors according to Placement of Functional Units and L2 Cache (코어 내부 구성요소와 L2 캐쉬의 배치 관계에 따른 멀티코어 프로세서의 온도 분석)

  • Son, Dong-Oh;Kim, Jong-Myon;Kim, Cheol-Hong
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.4
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    • pp.1-8
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    • 2014
  • As cores in multi-core processors are integrated in a single chip, power density increased considerably, resulting in high temperature. For this reason, many research groups have focused on the techniques to solve thermal problems. In general, the approaches using mechanical cooling system or DTM(Dynamic Thermal Management) have been used to reduce the temperature in the microprocessors. However, existing approaches cannot solve thermal problems due to high cost and performance degradation. However, floorplan scheme does not require extra cooling cost and performance degradation. In this paper, we propose the diverse floorplan schemes in order to alleviate the thermal problem caused by the hottest unit in multi-core processors. Simulation results show that the peak temperature can be reduced efficiently when the hottest unit is located near to L2 cache. Compared to baseline floorplan, the peak temperature of core-central and core-edge are decreased by $8.04^{\circ}C$, $8.05^{\circ}C$ on average, respectively.

An Effective Feature Extraction Method for Fault Diagnosis of Induction Motors (유도전동기의 고장 진단을 위한 효과적인 특징 추출 방법)

  • Nguyen, Hung N.;Kim, Jong-Myon
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.7
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    • pp.23-35
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    • 2013
  • This paper proposes an effective technique that is used to automatically extract feature vectors from vibration signals for fault classification systems. Conventional mel-frequency cepstral coefficients (MFCCs) are sensitive to noise of vibration signals, degrading classification accuracy. To solve this problem, this paper proposes spectral envelope cepstral coefficients (SECC) analysis, where a 4-step filter bank based on spectral envelopes of vibration signals is used: (1) a linear predictive coding (LPC) algorithm is used to specify spectral envelopes of all faulty vibration signals, (2) all envelopes are averaged to get general spectral shape, (3) a gradient descent method is used to find extremes of the average envelope and its frequencies, (4) a non-overlapped filter is used to have centers calculated from distances between valley frequencies of the envelope. This 4-step filter bank is then used in cepstral coefficients computation to extract feature vectors. Finally, a multi-layer support vector machine (MLSVM) with various sigma values uses these special parameters to identify faulty types of induction motors. Experimental results indicate that the proposed extraction method outperforms other feature extraction algorithms, yielding more than about 99.65% of classification accuracy.

Difference Across Indutries of Innovation Appropriability Mechanism's Effectiveness and Classification (기술혁신 보상확보 메커니즘 효과성의 산업별 차이와 유형)

  • Park, Seong Taek;Kim, Young Ki
    • Journal of Digital Convergence
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    • v.12 no.6
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    • pp.135-144
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    • 2014
  • In devising technological innovation strategies and implementing successful technological innovation, some of the most important factors may be to determine whether to protect technological innovation and to choose how to protect it. Traditionally, technological innovation has been emphasized to obtain compensation as much as possible for innovation in terms of economics and strategy. However, it can be regarded as a very complicated problem to determine such a protection and its level. Generally speaking, enterprises have some common mechanisms to secure compensation for technological innovation, which are known to be patents, secrecy and lead time advantage. From the standpoint of enterprises, it is very important what strategies should be devised to secure profits for technological innovation. According to some domestic and oversea research results revealed that specific patents are not the best way to Appropriability for technological innovation, while also implying that there exist several different kinds of mechanisms to Appropriability for technological innovation in each industry. Nevertheless, since it shouldn't be ignored that most of the researches have overlooked the characteristics of Korean enterprises and industrial differences, this study intends to clarify the effectiveness of technological innovation Appropriability mechanisms reflecting actual circumstances and industrial characteristics in Korea while classifying them. Also The questionnaires and delphi method used in this study. As the result of analysis, in the entire industries, the priorities turned out to be in the order of Superior sales and service efforts, Leadtime advantage, Complementary manufacturing.

Factors affecting regular medical care utilization of cardio-cerebrovascular patients (심뇌혈관 환자의 정기적 의료이용에 영향을 미치는 요인)

  • Seo, Young-Suk;Park, Jong-Ho;Lim, Ji-Hye
    • Journal of Digital Convergence
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    • v.12 no.7
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    • pp.327-336
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    • 2014
  • This study aims to identify factors to affect regular utilization status of medical care in cardio-cerebrovascular patients. The research selected 770 cardio-cerebrovascular patients among surveyees from the Korea Health Panel 2010. We analyzed states of medical care utilization using descriptive statistics. Logistic regression analysis was used to examine the main factors associated with regular utilization status of medical care in cardio-cerebrovascular patients. In result, the significant factors associated with regular utilization status of medical care in cardio-cerebrovascular patients were age, education level, household income level. CCI, presence or absence of high risk drinking, and presence or absence of obesity. There's a high probability that patients aged between 60 and 69, equal to and higher than those of high school graduate in education level, upper middle class in household income, the higher CCI, absence of high risk drinking, presence of obesity utilize medical care services more regularly. Therefore, it is necessary to develop effective program and individualized approach for patients using lesser periodical medical care and patients with high risk drinking problem. In the future, these findings can be used an important data for healthcare policy and assessment.

Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (II) - Development of Site Classification System (국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (II) - 지반분류 개선방법)

  • Yoon, Jong-Ku;Kim, Dong-Soo;Bang, Eun-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.2 s.48
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    • pp.51-62
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    • 2006
  • In the companion paper (I-Problem Statements of the Current Seismic Design Code), the current Korean seismic design code is required to be modified considering site characteristics in Korea for the reliable estimation of site amplification. In this paper, three site classification methods based on the mean shear wave velocity of the top 30m $V_{S30}$, fundamental site periods $(T_G)$ and bedrock depth were investigated and compared with each other to determine the best classification system. Not enough of a difference in the standard deviation of site coefficients $(F_a\;and\;F_v)$ to determine the best system, and neither is the difference between the average spectral accelerations and the design response spectrum of each system. However, the amplification range of RRS values based on $T_G$ were definitely concentrated on a narrow band than other classification system. It means that sites which have a similar behavior during earthquake will be classified as the same site category at the site classification system based on $T_G$. The regression curves between site coefficients and $T_G$ described the effect of soil non linearity well as the rock shaking intensity increases than the current method based on $V_{S30}$. Furthermore, it is unambiguous to determine sue category based on $T_G$ when the site investigation is performed to shallower depth less than 30m, whereas the current $V_{S30}$ is usually calculated fallaciously by extrapolating the $V_s$ of bedrock to 30m. From the results of this study, new site classification system based on $T_G$ was recommended for legions of shallow bedrock depth in Korea.

Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (I) - Problem Statements of the Current Seismic Design Code (국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (I) - 국내 내진설계기준의 문제점 분석)

  • Yoon, Jong-Ku;Kim, Dong-Soo;Bang, Eun-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.2 s.48
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    • pp.39-50
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    • 2006
  • Site response analyses were peformed based on equivalent linear technique using the shear wave velocity profiles of 162 sites collected around the Korean Peninsula. The she characteristics, particularly the shear wave velocities and the depth to bedrock, are compared to those in the western United States. The site coefficients of short period $(F_a)$ and the long period $(F_v)$ obtained from this study were significantly different compared to 1997 Uniform Building Code (1997 UBC). $F_a$ underestimated the motion in shot period ranges and $F_v$ overestimated the motion in mid period ranges in Korean seismic guideline. It is found that the existing Korean seismic design code were is required to be modified considering geological site conditions in Korea for the reliable estimation of sue amplification. Problems of the current seismic design code were dicussed in this paper and the development of site classification method and modification of desing response spectra were discussed in the companion papers(II-Development of Site Classification System and III-Modification of Dosing Response Specra).

Design of Sliding Mode Fuzzy Controller for Vibration Reduction of Large Structures (대형구조물의 진동 감소를 위한 슬라이딩 모드 퍼지 제어기의 설계)

  • 윤정방;김상범
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.3
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    • pp.63-74
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    • 1999
  • A sliding mode fuzzy control (SMFC) algorithm is presented for vibration of large structures. Rule-base of the fuzzy inference engine is constructed based on the sliding mode control, which is one of the nonlinear control algorithms. Fuzziness of the controller makes the control system robust against the uncertainties in the system parameters and the input excitation. Non-linearity of the control rule makes the controller more effective than linear controllers. Design procedure based on the present fuzzy control is more convenient than those of the conventional algorithms based on complex mathematical analysis, such as linear quadratic regulator and sliding mode control(SMC). Robustness of presented controller is illustrated by examining the loop transfer function. For verification of the present algorithm, a numerical study is carried out on the benchmark problem initiated by the ASCE Committee on Structural Control. To achieve a high level of realism, various aspects are considered such as actuator-structure interaction, modeling error, sensor noise, actuator time delay, precision of the A/D and D/A converters, magnitude of control force, and order of control model. Performance of the SMFC is examined in comparison with those of other control algorithms such as $H_{mixed 2/{\infty}}$ optimal polynomial control, neural networks control, and SMC, which were reported by other researchers. The results indicate that the present SMFC is an efficient and attractive control method, since the vibration responses of the structure can be reduced very effectively and the design procedure is simple and convenient.

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A Study on Message Set of VMS on Express way and Evaluation of Driver's Preference (고속도로 VMS Message Set 연구 및 이용자 선호도 평가)

  • Kim, Nam-Sun;Jee, Dong-Mok;Oh, Young-Tae;Lee, Hwan-Pil;Kim, Sang-Bok
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.4
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    • pp.1-13
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    • 2009
  • VMS(Variable Message Sign) which makes the traffic flow smooth by providing traffic information to road users in real-time has been being installed or operated on the road as part of the detailed ITS system. However, some problems were found as a result of survey on express way currently. In the part of the phase operation, the message interpretation time wasn't defined so that the phase operation was difficult. In the part of the information service, not considering characteristic of the VMS section caused the confusion to drivers. In the part of the message exposure, font, alignment, conversion and composition of the information were not consistent and use of superfluous words and inconsistent use of word having the same meaning brought about the problem on information communication This study established the detailed exposure method based on instructions relative to VMS operation. The method established by defining the number of appropriate phase and setting required function of each individual VMS installation location. The method is as follow. the font type is the GULIM, the message conversion method is simple conversion method, the alignment method is centering alignment method and the color is defined according to each situation. In this study, the preference survey was performed to review the validity of the proposed improvement through the common driver. The results were similar with the pre-study except for the font type. This study established the detailed exposure method based on instructions relative to VMS operation. The method established by defining the number of appropriate phase and setting required function of individual VMS installation location. For the evaluation of status and improvement, preference survey of ordinary drivers and statistics analysis was carried.

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