• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.205-205
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• 2021

Surface soil moisture, which governs the partitioning of precipitation into infiltration and runoff, plays an important role in the hydrological cycle. The assimilation of satellite soil moisture retrievals into a land surface model or hydrological model has been shown to improve the predictive skill of hydrological variables. This study aims to improve streamflow prediction with Weather Research and Forecasting model-Hydrological modeling system (WRF-Hydro) by assimilating Soil Moisture Active and Passive (SMAP) data at 3 km and analyze its impacts on hydrological components. We applied Cumulative Distribution Function (CDF) technique to remove the bias of SMAP data and assimilate SMAP data (April to July 2015-2019) into WRF-Hydro by using an Ensemble Kalman Filter (EnKF) with a total 12 ensembles. Daily inflow and soil moisture estimates of major dams (Soyanggang, Chungju, Sumjin dam) of South Korea were evaluated. We investigated how hydrologic variables such as runoff, evaporation and soil moisture were better simulated with the data assimilation than without the data assimilation. The result shows that the correlation coefficient of topsoil moisture can be improved, however a change of dam inflow was not outstanding. It may attribute to the fact that soil moisture memory and the respective memory of runoff play on different time scales. These findings demonstrate that the assimilation of satellite soil moisture retrievals can improve the predictive skill of hydrological variables for a better understanding of the water cycle.

• 한국환경과학회지
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• 제13권4호
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• pp.327-337
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• 2004

The education effect of environmental impact cognitive instruction on high school students was investigated. Environmental values of students could be classified into egocentric, social-altruistic and biospheric values like those of Schultz’s three kinds of categories. The value distribution of students consists 44.7% of egocentric and biospheric value groups and 12.5% of social-altruistic value group, respectively. The environmental function such as knowledge and skill did not show remarkable differences between value groups. The environmental value only affected the attitude function. The biospheric value group had the higher attitude function than other value groups. The environmental impact cognitive instruction enhanced the environmental functions irrespective of the value group or instruction type. However, significant variables were different according to environmental functions. Environmental functions such as knowledge and skill were influenced by the instruction itself. The attitude function was dependent on instruction itself, value type and instruction type. The optimum application of the environmental impact cognitive instruction can be efficiently achieved through class division into egocentric value group and biospheric value group. Alternatively, the proper combination of instruction methods focused biospheric and egocentric impacts in a class can be recommended.

• 대한원격탐사학회지
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• 제32권4호
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• pp.339-351
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• 2016

For the safety of sea, it is important to monitor sea fog, one of the dangerous meteorological phenomena which cause marine accidents. To detect and monitor sea fog, Moderate Resolution Imaging Spectroradiometer (MODIS) data which is capable to provide spatial distribution of sea fog has been used. The previous automatic sea fog detection algorithms were focused on detecting sea fog using Terra/MODIS only. The improved algorithm is based on the sea fog detection algorithm by Wu and Li (2014) and it is applicable to both Terra and Aqua MODIS data. We have focused on detecting spring season sea fog events in the Yellow Sea. The algorithm includes application of cloud mask product, the Normalized Difference Snow Index (NDSI), the STandard Deviation test using infrared channel ($STD_{IR}$) with various window size, Temperature Difference Index(TDI) in the algorithm (BTCT - SST) and Normalized Water Vapor Index (NWVI). Through the calculation of the Hanssen-Kuiper Skill Score (KSS) using sea fog manual detection result, we derived more suitable threshold for each index. The adjusted threshold is expected to bring higher accuracy of sea fog detection for spring season daytime sea fog detection using MODIS in the Yellow Sea.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.147-157
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• 2020

In the accounting information system implementation, the users should consider the benefits and advantages of the system. This paper examines the effect of the Enterprise Resources Planning based (ERP-based) accounting information system implementation on user impact and organizational impact. The population in this study is companies listed on the Indonesian Stock Exchange, especially companies based in Riau, Indonesia. These companies currently use the ERP-based accounting information system. Research samples are employees who use the ERP-based accounting information system. For data analysis, we use structural equation modeling (SEM). Based on data analysis, high-quality information system implementation generate high-quality information that can give satisfaction to the user. Moreover, the information system is related to user skill, satisfaction, and knowledge sharing which improve personal skills; enhanced personal skill contributes to organizational performance. On the other hand, there is no effect of training on personal skills and there is no effect of information quality on perceived usefulness. This research gives implication to the organization for implementing a high-quality ERP-based accounting information system that positively impacts organizational performance. Future research is expected to examine information system implementation in different research objects and conditions.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.289-306
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• 2021

This paper aims to investigate how and to what extent FDI impacts the relative demand for skilled labor within firms in the case of developing countries. The analysis uses a sizeable micro-level dataset for Malaysian manufacturing industries using the System-GMM estimators to control the estimations' endogeneity problems. For this purpose, the study uses foreign equity share at the firm level to investigate foreign ownership effects at the firm level and the Horizontal FDI index by Smarzynska Javorcik (2004) to analyze FDI intra-industry linkages influence on the structure of labor demand for Malaysian domestic firms. Our findings indicate that foreign ownership increases the skilled demand within Malaysian manufacturing through the learning process, exclusively for small- and medium-sized firms (SMEs). Conversely for foreign-owned firms, changes in their skilled-labor share do not associate with changes in firm-level foreign equity share. We conclude that foreign ownership per se is not the major contributing factor for skill upgrading in Malaysian manufacturing firms. Furthermore, the competitive pressures caused by foreign firms' presence within the same industry - namely horizontal FDI - has a significant negative spillover effect on the level of skilled-labor share for domestic firms in the Malaysian manufacturing sector within periods of the understudies.

• 대기
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• 제33권5호
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• pp.519-530
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• 2023

Deep convection can make adverse effects on safe and efficient aviation operations by causing various weather hazards such as convectively-induced turbulence, icing, lightning, and downburst. To prevent such damage, it is necessary to accurately predict spatiotemporal distribution of deep convective area near the airport and airspace. This study developed a new index, the Aviation Convective Index (ACI), for deep convection, using the operational global Unified Model of the Korea Meteorological Administration. The ACI was computed from combination of three different variables: 3-hour maximum of Convective Available Potential Energy, averaged Outgoing Longwave Radiation, and accumulative precipitation using the fuzzy logic algorithm. In this algorithm, the individual membership function was newly developed following the cumulative distribution function for each variable in Korean Peninsula. This index was validated and optimized by using the 1-yr period of radar mosaic data. According to the Receiver Operating Characteristics curve (AUC) and True Skill Score (TSS), the yearly optimized ACI (ACI_YrOpt) based on the optimal weighting coefficients for 1-yr period shows a better skill than the no optimized one (ACI_NoOpt) with the uniform weights. In all forecast time from 6-hour to 48-hour, the AUC and TSS value of ACI_YrOpt were higher than those of ACI_NoOpt, showing the improvement of averaged value of AUC and TSS by 1.67% and 4.20%, respectively.

• 디지털콘텐츠학회 논문지
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• 제15권4호
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• pp.465-471
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• 2014

본 논문는 사용자가 전문적인 프로그래밍 지식 없이, WYSIWYG 방식으로 웹페이지의 특정 위치에 웹서비스를 추가함으로써 사용 가능한 개인화 서비스 환경과, 표준의 웹을 보여주는 웹브라우징 인터페이스 형태가 공존하는 소프트웨어 하이브리드 플랫폼에 관한 것이다. 기존의 인터넷 페이지를 수정하지 않고 편리하게 서비스를 추가할 수 있는 저비용/고효율의 소프트웨어 개인화 플랫폼을 구현함으로, 통제 가능한 개인화 서비스 작업 환경을 제공한다. 따라서 사용자가 방문한 웹사이트를 기반으로 소프트웨어나 콘텐츠를 유통 시킬 수 있는 유통 환경이 제공되어, 기존에 존재하는 웹사이트를 더욱 풍부하게 하는 콘텐츠 생태계를 구성할 수 있는 개인화 하이브리드 플랫폼을 제시한다.

• 산업경영시스템학회지
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• 제20권43호
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• pp.47-57
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• 1997

As a general index in surface quality of machined products, surface roughness is to measure worker's skill level, a ground product quality and machining accuracy, etc. The surface roughness is defined by a function of rotational speed and radius of a grinding wheel, distances of active grains composed of the wheel, and feed of a grinder's worktable. To predict surface roughness in horizontal surface grinding operations, probability distributions were used. Probability distribution functions(p.d.f.) of surface roughness were found as results when the size of active grains(=the radius of a grinding wheel) is given as uniform, exponential distribution, and the distance between active grains follows the distributions of uniform, exponential. For each pdf case, probabilistic features of surface roughness were also analyzed and presented. This study is a substantial step for determining mathematically the surface roughness instead of using empirical approaches. More works should be presented to develop a general model by which an accurate roughness value can be obtained in horizontal surface grinding operations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1476-1477
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• 2006

Solid insulation exposed to voltage is degraded and by electrical tree process. And the degradation of the insulation is accelerated by voltage application. For this experimental, specimen of electrical tree model is made by XLPE(cross-linked polyethylene). And the size of the specimen is 7*5*7 $mm^3$. Distance of needle and plane is 2mm. Voltage applied for acceleration test are 12kV. And distribution characteristic of degraded stage is studied too. As a PD detecting and data process, discharge data acquire from PD detecting system(Biddle instrument). Their results of PD distribution show good present and are good discriminating skill.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.143-150
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• 1999

The LRFD Specification defines two sets of limiting width-to-thickness ratios. On the basis of these limiting values, steel sections we subdivided into three categories: compact, noncompact, and slender sections. A compact section is capable of developing a fully plastic stress distribution (plastic moment), and can sustain rotations approximately three times beyond the yield before the possibility of local buckling arises. Noncompact sections can develop the yield stress before local buckling occurs. They may not, however, resist local buckling at the strain levels required to develop the fully plastic stress distribution. In this paper, 1-Type girders of a 2 span continuous steel bridge are divided into compact and non-compact sections and analyzed. In the design process, an optimization skill was adopted and ADS, a Fortran program for Automated Design Synthesis, was used.