• Journal of Forest and Environmental Science
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• 제36권1호
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• pp.1-6
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• 2020

This study was conducted to investigate the effect of different pre-sowing treatments of seeds on germination and growth performance of native threatened tree species Quercus gomeziana A. Camus at the nursery of Chittagong University, Bangladesh. Furthermore, seedling growth attributes under different doses of fertilizer (urea) was also experimented to find the best dose of fertilizer on this tree species at the nursery stage for better field level growth. Seeds were placed to six pre-sowing treatments e.g. control (PT₀), treated with sand paper rubbing (PT₁), nicking (PT₂), seeds immersed in cold water for 48 hours (PT₃), seeds immersed in cold water for 7 days (PT₄) and seeds sown at propagator house with increased temperature (PT₅). It was found from the study that germination was started earlier (at 31 days) in treatments sand paper rubbing (PT₁) and nicking (PT₂). The highest germination percentage (93%) was in PT₁ followed by 86% in seeds immersed in cold water for 7 days (PT₄) and 80% in PT₀ (control). Germination percentage was observed least (63%) in PT₂ even though germination started earlier. For fertilizer dose experiment to seedlings at the nursery level, treatment FT₁: 100 kg/ha (0.33679 g urea/pot/seedling) comparing with other treatments FT₀: 0 kg/ha (Control), FT₂: 200 kg/ha (0.67358 g urea/pot/seedling), FT₃: 300 kg/ha (1.01037 g urea/pot/seedling) showed better performance in case of collar diameter (6.74 mm), number of leaves, shoot dry weight (19.74), total dry weight (28.16 g), total fresh weight (67.96 g), volume index (3904.82), sturdiness (127.69). Finally, it can be concluded that Quercus gomeziana seedlings revealed better performances under the treatment FT₁ in growth and biomass production. Findings of this study will be helpful to take decision on organic fertilizer dose application to seedlings of Q. gomeziana for large scale plantation and conservation of this species.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.65-70
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• 2001

Six recycling plants have started operation for recycling scrap home appliances since the spring of 2000 in Taiwan. The performance of the plants has not yet been measured during the 18-month period. The performance measurement, however, can be looked in several aspects. Because of the nature of these recycling plants, at least three aspects, namely government (representing general public), appliance manufacturers and owners of the recycling plants themselves should be considered in the performance evaluation. This study proposes various performance indices categorized in four groups: profitability, recyclability, automation and environment. The indices are different from the productivity and cost measures that are used in conventional manufacturing plants. Performances of three existing plants in Taiwan are evaluated as illustrative examples to demonstrate the use of the proposed measures. The practical implications of the performance indices are also discussed.

• 한국건축시공학회지
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• 제11권2호
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• pp.189-199
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• 2011

도심지 환경 개선을 위한 인공지반녹화(옥상녹화 등)사업의 확대 보급을 위해서는 옥상부 구조체의 장기적 안정성을 보증할 수 있는 안전한 방수방근층을 구성하여야한다. 따라서 인공지반 녹화용 방수방근층은 식물 뿌리의 침입으로부터 안전해야 하며, 녹화부의 잔류수 및 침체수 등에 대해 장기적으로 수밀해야 하며, 식물 성장에 필요한 비료 등의 화학물질 및 기타의 화학성분에 장기적으로 안전해야 하며, 시공 시에 발생하는 각종 공구류, 설비류, 가설물에 의해 손상되지 않아야 하고, 식재 및 토심의 하중, 설비류의 하중에 의해 손상되지 않는 종합적 성능이 요구된다. 이에 본 연구에서는 옥상녹화 현장의 환경 조건을 대상으로 방수방근층의 환경 성능 지표를 설정하였고, 이와 관련한 방근성능, 수밀성능, 내움패임 저항성능, 충격저항성능, 내화학성능을 방수방근층의 요구 성능으로 정하였으며, 그와 관련한 평가 방법을 제시하고, 실무적인 검증 시험을 통하여 복합 방수방근층의 성능 평가 시스템을 제안하였다.

• Earthquakes and Structures
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• 제8권3호
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• pp.573-589
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• 2015

In order to investigate the seismic behavior of highway bridges under near-fault earthquakes, a parametric study was conducted for different regular and irregular bridges. To this end, an existing regular viaduct Highway Bridge was used as a reference model and five irregular samples were generated by varying span length and pier height. The seismic response of the six highway bridges was evaluated by three dimensional non-linear response history analysis using an ensemble of far-fault and scenario-based near-fault records. In this regard, drift ratio, input and dissipated energy as well as damage index of bridges were compared under far- and near-fault motions. The results indicate that the drift ratio under near-fault motions, on the average, is 100% and 30% more than far-fault motions at DBE and MCE levels, respectively. The energy and damage index results demonstrate a dissipation of lower energy in piers and a significant increase of collapse risk, especially for irregular highway bridges, under near-fault ground motions.

• 통상정보연구
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• 제14권2호
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• pp.349-367
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• 2012

최근 대량생산에 기초한 세계 경제의 패러다임이 공급과잉과 개도국 위주의 지나친 양적 경쟁으로 인한 폐해로 인하여 환경악화와 각국간 갈등구조 심화 등 새로운 문제로 분출되면서 이와 같은 외부효과의 내재화와 생산 과정의 투명성, 예측가능성의 글로벌 표준에 입각한 지속가능 경쟁체제에 대한 패러다임이 급속히 확산되고 있다. 특히 제2차 G20정상회의를 계기로 전세계적인 녹색성장을 새로운 패러다임으로 제시한 한국경제에 있어 환경문제는 매우 심각하며, 그 어느 분야보다 친환경적인 녹색생산성에 입각한 지속가능한 국제경쟁력의 강화가 시급한 상황이라 할 것이다. 선진국으로의 진입을 목전에 둔 상황에서 기존의 투입대비 산출량의 극대화를 위한 생산성 향상전략은 그 내재적인 한계가 심각한 상황에 이르고 있기 때문이다. 이를 극복하여 지속가능한 국가경쟁력을 강화하기 위한 핵심적인 의제는 바로 녹색성장을 위한 효율성, 즉 녹색생산성에서 비롯된다고 할 것이다. 이를 위해 기존의 전통적 생산성개념에 환경오염변수를 고려한 방향적 거리함수(directional distance function)와 Malmquist 지수 (ML지수)가 개발되면서 다양한 논의가 진행되었고, 본 연구는 그 가운데에서도 가장 최근에 새롭게 제시된 연구방법론적 특성과 경영환경의 특성을 감안한 총체적 ML지수 (Global Malmquist-Luenberger Index, GML) 연구 모형을 소개하여 환경 보호와 경제개발을 조화롭게 추진하기 위한 녹색생산성의 실질적인 효과를 분석하기 위한 종합적이고도 체계적인 패러다임을 제시하고자 한다.

• 대기
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• 제33권5호
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• pp.531-548
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• 2023

We developed the Aviation Convective Index (ACI) for predicting deep convective area using the operational global Numerical Weather Prediction model of the Korea Meteorological Administration. Seasonally optimized ACI (ACI_SnOpt) was developed to consider seasonal variabilities on deep convections in Korea. Yearly optimized ACI (ACI_YrOpt) in Part 1 showed that seasonally averaged values of Area Under the ROC Curve (AUC) and True Skill Statistics (TSS) were decreased by 0.420% and 5.797%, respectively, due to the significant degradation in winter season. In Part 2, we developed new membership function (MF) and weight combination of input variables in the ACI algorithm, which were optimized in each season. Finally, the seasonally optimized ACI (ACI_SnOpt) showed better performance skills with the significant improvements in AUC and TSS by 0.983% and 25.641% respectively, compared with those from the ACI_YrOpt. To confirm the improvements in new algorithm, we also conducted two case studies in winter and spring with observed Convectively-Induced Turbulence (CIT) events from the aircraft data. In these cases, the ACI_SnOpt predicted a better spatial distribution and intensity of deep convection. Enhancements in the forecast fields from the ACI_YrOpt to ACI_SnOpt in the selected cases explained well the changes in overall performance skills of the probability of detection for both "yes" and "no" occurrences of deep convection during 1-yr period of the data. These results imply that the ACI forecast should be optimized seasonally to take into account the variabilities in the background conditions for deep convections in Korea.

• Communications for Statistical Applications and Methods
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• 제18권1호
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• pp.119-130
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• 2011

본 연구의 목적은 한국 보험회사의 지속가능성과를 측정하고 분석하여 지속가능경영을 위한 전략적 시사점을 제공하는데 있다. 분석방법으로는 상관분석, 회귀분석, 분산분석, T-검정을사용한다. 분석결과 첫째, 생명보험에서는 사회지표가, 손해보험에서는 환경지표가 상대적으로 중요한 변수로 분석되었다. 둘째, 지속가능점수를 종속변수로 하고 기업의 규모와 재무건전성을 독립변수로 한 회귀분석 결과규모가 통계학적으로 유의하게 정(+)의 영향을 미치는 변수로 분석되었다. 이는 지속가능성장을 위한 필요조건으로 일정 수준 이상의 규모가 요구됨을 시사한다. 셋째, 분산분석 및 T-검정 결과 생명보험산업에서는 중소형사가 대형사에 비해 사회지표 및 명성지수에서 통계학적으로 유의하게 낮은 성과를 보여주는 것으로 나타났다. 손해보험산업에서는 중소형사가 대형사에 비해 사회지표를 제외한 모든 지표에서 통계학적으로 유의하게 낮은 성과를 보여주는 것으로 나타났다. 따라서 중소형사의 지속가능한 발전을 위해서는 생명보험의 경우 사회지표 및 명성지표 측면에서, 손해보험의 경우는 경제, 환경, 명성 등의 측면에서 노력이 요구되어진다고 볼 수 있다.

• Journal of information and communication convergence engineering
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• 제20권3호
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• pp.181-188
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• 2022

An intelligent distributed multi-agent system (IDMS) using reinforcement learning (RL) is a challenging and intricate problem in which single or multiple agent(s) aim to achieve their specific goals (sub-goal and final goal), where they move their states in a complex and cluttered environment. The environment provided by the IDMS provides a cumulative optimal reward for each action based on the policy of the learning process. Most actions involve interacting with a given IDMS environment; therefore, it can provide the following elements: a starting agent state, multiple obstacles, agent goals, and a cluttered index. The reward in the environment is also reflected by RL-based agents, in which agents can move randomly or intelligently to reach their respective goals, to improve the agent learning performance. We extend different cases of intelligent multi-agent systems from our previous works: (a) a proposed environment-clutter-based-index for agent sub-goal selection and analysis of its effect, and (b) a newly proposed RL reward scheme based on the environmental clutter-index to identify and analyze the prerequisites and conditions for improving the overall system.

• 한국농공학회논문집
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• 제62권3호
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• pp.51-61
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• 2020

Drought events are not clear when those start and end compared with other natural disasters. Because drought events have different timing and severity of damage depending on the region, various studies are being conducted using satellite images to identify regional drought occurrence differences. In this study, we investigated the applicability of drought assessment using the Evaporative Stress Index (ESI) based on Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images. The ESI is an indicator of agricultural drought that describes anomalies in actual and reference evapotranspiration (ET) ratios that are retrieved using remotely sensed inputs of Land Surface Temperature (LST) and Leaf Area Index (LAI). However, these approaches have a limited spatial resolution when mapping detailed vegetation stress caused by drought, and drought hazard in the actual crop cultivation areas due to the small crop cultivation in South Korea. For these reasons, the development of a drought index that provides detailed higher resolution ESI, a 500 m resolution image is essential to improve the country's drought monitoring capabilities. The newly calculated ESI was verified through the existing 5 km resolution ESI and historical records for drought impacts. This study evaluates the performance of the recently developed 500 m resolution ESI for severe and extreme drought events that occurred in South Korea in 2001, 2009, 2014, and 2017. As a result, the two ES Is showed high correlation and tendency using Receiver Operating Characteristics (ROC) analysis. In addition, it will provide the necessary information on the spatial resolution to evaluate regional drought hazard assessment and and the small-scale cultivation area across South Korea.

• 한국환경과학회지
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• 제14권3호
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• pp.289-296
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• 2005

In this study aims is water supply criteria relations for evaluating the possible performance of water resources systems. These measures describe how likely a systems is to fail(reliability), how quickly it recovers from failure(resiliency), and how severe the consequences of failure may be(vulnerability). The performance of a criteria evaluating with a variety of operating policies illustrates their use. As a result study frequency reliability and quantitative reliability is linear relations and quantitative reliability is high reliability for equality water supply policy. As reliability and vulnerability are in inverse proportion to each other. Therefore these criteria relation analysis can be for Imha dam to variety water supply policy.