• Asian Journal of Atmospheric Environment
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• 제6권1호
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• pp.1-13
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• 2012

To identify the primary factor affected the decreased $PM_{10}$ concentration in Seoul which is the capital city of Korea, wind speed and emissions in 2003 and 2004 were analyzed. The level of air pollution is intense in Seoul and continually increased since the late 1990s. However the concentration of $PM_{10}$ has been greatly declined recently. In particular, the concentration of $PM_{10}$ decreased 14% in 2003 and 2004 excluding the Asian dust periods. It is suggested that the major factors for the decrease are differences in wind speed between the two years and the period of constant breeze. In 2003, intense Asian dust events happened frequently and it increased the concentration of total $PM_{10}$. The intense dust events were influence by the speed and duration of the wind. It is considered that the meteorological condition was the primary drive for the change of the concentration of $PM_{10}$. The decreased emissions seem to be the additional factor for the change in the concentration of $PM_{10}$.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.267-269
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• 2009

본 연구는 전 세계 유류 화물의 해상 수송 영업력 강화를 위해 정유 회사에서 요구하는 특수선 안전 관리 방안에 관한 사항을 연구 분석하였다. 유류 화물 운송 선박의 해상 안전 및 해양 오염 사고는 해운 회사 뿐 아니라 정유회사까지 막대한 재산상의 손실을 발생시키고 또한, 유류 사고는 회사의 존폐를 위협할 정도로 심각한 영향을 끼칠 수 있다. 그러한 이유로, 정유회사는 각 선박관리회사 및 선박의 안전 관리 시스템에 관한 평가를 주기적으로 실시하고 있으며, 선박안전검사보고서는 OCIMF 및 CDI에서 인터넷 홈페이지를 통해 상호 공유하고 있고 유류 화물 수송시, 절대적으로 중요한 데이터로 활용하고 있다. 이에 본 연구는 유류 화물 영업력 강화를 위해 특수선사 화물 영업 책임자 및 안전경영책임자에게 실질적 방법론을 제공하고 다양한 체제에서 운용할 수 있는 특수선 안전 관리 방안에 대한 기초가 될 것이다.

• Weed & Turfgrass Science
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• 제3권3호
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• pp.174-182
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• 2014

This paper provides some of the scientific background on how projected environmental conditions could affect weeds and weed management in crops. Elevated $CO_2$ levels may have positive effects on crop competitiveness with $C_4$ weeds, but these are generally outnumbered by $C_3$ species in weed populations. Moreover, higher temperatures and drought will favor $C_4$ over $C_3$ plants. The implementation of climate change adaptation technologies, such as drought-tolerant germplasm and water-saving irrigation regimes, will have consequences for crop-weed competition. Rainfed production systems are thought to be most vulnerable to the direct effects of climate change and are likely to face increased competition from $C_4$ and parasitic weeds. Biotic stress-tolerant crop cultivars to be developed for these systems should encompass weed competitiveness and parasitic-weed resistance. In irrigated systems, indirect effects will be more important and weed management strategies should be diversified to lessen dependency on herbicides and mechanical control, and be targeted to perennial rhizomatous ($C_3$) weeds. Water-saving production methods that replace a weed-suppressive floodwater layer by intermittent or continuous periods of aerobic conditions necessitate additional weed management strategies to address the inherent increases in weed competition. Thus, climatic conditions have a great effect on weed population dynamics all over the world.

• 한국수자원학회논문집
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• 제52권3호
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• pp.195-206
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• 2019

본 연구에서는 주 단위 지하수자원 관리 취약시기 평가 방법을 개발하였다. 강수의 지하수위에 대한 영향을 고려하기 위하여 한계 침투량을 고려한 강우이동평균 방법을 통해 지하수위와의 상관계수를 산정하였다. 취약 시기 평가 기준을 개발하고 평가 기준에 대한 가중치를 엔트로피 방법을 이용하여 산정하였다. 강수와의 상관계수와 산정된 가중치를 이용한 주 단위 지하수자원 관리 취약시기 평가 방법을 개발하였으며, 개발한 방법을 통하여 소규모 행정구역을 대상으로 취약시기를 평가하였다. 본 연구에서 개발된 방법은 지역적일뿐만 아니라 계절적인 지하수자원의 효율적 관리 대책 수립의 근거가 될 수 있을 것이다.

• 기록학연구
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• 제10호
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• pp.226-273
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• 2004

The characteristics of the records management systems of the Japanese colonial government can be summarized as follows. First, the Government General adopted a "decentralized retention" of public records. The Government General did not establish its own archives for central preservation of permanent public records. Colonial agencies established its own records office and the records office managed the records its agency created. Secret records and police records were exception. They were retained by the Secretary Office of the General Affairs Division and Police Division of the Chosun Government General respectively. Second, filing systems and retention periods of the public records followed the hierarchic structure of organization. In the headquarter of the government, records were filed by a "bureau-division-activity-file" classification system and a retention period of a file was given automatically by each unit the file belonged. A closed and cut-off file was retained and arranged according to its creating unit, creating year, and retention period. The filing system was easy to use once the filing system was established well, but to make it work effectively changes in activities and organizations should be on a reflected regular basis. It had an advantageous effect that permanent records could be preserved in a unified way throughout the organization. However, it is very critical to determine the permanent records in a professional way. Selection of the permanent records should be done professionally and in a historical perspective. Otherwise, the records retained as permanent records were not the records having an enduring value. And that was not done by the colonial government. Third, classification and scheduling of records were carried out by a creating division, rather than by the Records Office, mostly from the 1920s. Compilation of the records was also done by the creating agency. It implies that the records management lacked the professionalism. In conclusion, the records management system of the Chosun Government General wes nither modern nor user oriented. It managed the records for solely administrative purpose, i.e. effective colonial rule. The legacy of the colonial records system still exists in the public records system in Korean government. One should criticize the lack of will and efforts to modernize the public records system since the establishment of the Korean government while should reflect the historical origins of the records system in Korea.

• 한국환경보건학회지
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• 제49권5호
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• pp.275-288
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• 2023

Background: When basic local governments want to improve their air quality management policies, they need fundamental evidence, such as the effectiveness of current policies or scenario results. Objectives: The purpose of this study is to lay the groundwork for a process to calculate air pollutant reduction from basic local government air quality policies and provide numerical estimates of PM_2.5 concentrations following improved policies. Methods: We calculated the amount of air pollutant reduction that can be expected in the research region based on the Gyeonggi-do Air Environment Management Implementation Plan issued in 2021 and guidelines from the Korean Ministry of Environment. The PM_2.5 concentration variations were numerically simulated using the CMAQ (photochemical air quality model). Results: The research regions selected were Suwon, Ansan, Yongin, Pyeongtaek, and Hwaseong in consideration of population, air pollutant emissions, and geographical requirements. The expected reduction ratios in 2024 compared to 2018 are CO (3.0%), NO_x (7.9%), VOCs (0.7%), SO_x (0.1%), PM₁₀ (2.4%), PM_2.5 (6.1%), NH₃ (0.05%). The reduced PM_2.5 concentration ratio was highest in July and lowest in April. The expected concentration reduction of yearly mean PM_2.5 in the research region is 0.12 ㎍/m³ (0.6%). Conclusions: Gyeonggi-do is now able to quickly provide air pollutant emission reduction calculations by respective policy scenario and PM_2.5 simulation results, including for secondary aerosol particles. In order to provide more generalized results to basic local governments, it is necessary to conduct additional research by expanding the analysis tools and periods.

• 품질경영학회지
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• 제51권4호
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• pp.481-496
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• 2023

Purpose: The main theme of this study is to derive a profit curve by a cubic cost function for nonlinear CVP analysis. According to the analytical approach to derive a nonlinear profit function in this study, it is possible with only the existing cost structure to calculate the profit maximization and downtime point sales unlike the classical CVP analysis. Furthermore, the profit curve by the mathematical model of this study could serve as a tool to quantify the qualitative evaluation of each stage of the industry life cycle. Methods: This study followed the mathematical approach from the cubic cost function model of microeconomics, and using real data of the Bank of Korea Results: The nonlinear profit function suggested by this study is as follows; ${\pi}(x)=-a\left(x-\frac{f}{1-v}\right)^3+(1-v)x-k$ where $a=\frac{1}{3}v\left(\frac{(1-v)}{f}\right)^2,k=f-a\left(1-\frac{f}{1-v \right)^3$ Conclusion: The process and results of this study would be able to contribute not only in practice of nonlinear CVP analysis required in the management accounting or financial management, but also in cost theory of microeconomics. Also, since the life cycle of all industries in Korea was verified to the growth or mature stage, decision makers should pay careful attention to determining life cycle stages and consider the profit curve by the average variable cost ratio over multi periods.

• Journal of Ecology and Environment
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• 제48권1호
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• pp.60-73
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• 2024

Background: The available information on terrestrial pest gastropods and their impact on the environment worldwide is scarce and outdated. The present study aimed to address this gap by conducting the first comprehensive survey of pest gastropods in the Nuwara Eliya District, an important vegetable growing area in the highlands of Sri Lanka. Eighty agricultural lands were surveyed over two years by establishing ten 1 m2 sampling plots per crop type in each agricultural land. Geo-coordinates, air temperature, elevation, relative humidity, daily rainfall, soil pH, species richness and abundance were recorded for rainy and non-rainy periods. The relationship between species composition and environmental variables was analyzed using multi-regression models and distribution maps. Results: Out of the 14 species recorded in agricultural lands, nine were identified as exotic pest species. Species abundance (t = 4.69, p < 0.05) and diversity was higher in the rainy period and the dominant species during this period were Bradybaena similaris (t = 2.69, p < 0.05) and Deroceras reticulatum (t = 2. 46, p < 0.05). Eggs and estivating adults were found in soil and under decaying organic matter during the non-rainy period. The exotic species showed broader preferences for the measured environmental factors and showed a wider range in distribution compared to the native species. Variation in pest gastropod composition was significantly accounted for by elevation, relative humidity, soil pH and daily rainfall. Additionally, the species richness and abundance varied across locations due to the combined effects of elevation, crop type and stage, and field type. Conclusions: The study emphasizes the importance of understanding the biology and ecology of gastropod pests to develop effective management strategies. By considering the influence of environmental factors and implementing appropriate soil management techniques, such as targeting specific habitats and crop stages, it is possible to mitigate pest populations and minimize their impact on agricultural lands. Overall, this research contributes valuable insights into the dynamics and interactions of terrestrial gastropods in agricultural ecosystems, supporting sustainable pest management practices.

• 재무관리연구
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• 제25권2호
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• pp.165-190
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• 2008

선물 및 옵션의 만기결제와 관련된 정보비대칭 상황은 각 투자자 집단의 거래활동에 가시적인 영향을 줄 수 있다. 이러한 가능성을 조사하기 위해서 본 연구는 만기일을 제외한 파생상품의 life cycle을 시간의 경과에 따라 3개의 구간으로 설정한 후, 각 투자자 유형의 거래활동이 각 구간별로 보이는 변화 패턴을 조사하였다. 조사된 KOSPI200 지수 파생상품시장의 투자자 유형별 거래행태는 Foster and Viswanathan(1990)의 전략적 유동성 거래자 모형을 통해서 해석되었다. 한편, 투자자 유형별로 KOSPI200 지수 파생상품의 만기결제와 관련된 정보우위성을 측정 및 비교함으로써 정보비대칭 정도 및 정보거래자의 확인(identification) 문제에 조금 더 접근할 수 있었다. 본 연구의 주요 결과는 다음과 같이 요약된다. 첫째, 투자자 집단의 거래활동은 KOSPI200 지수 파생상품의 life cycle에 따라 3가지 유형(ㄱ자형, L자형, U자형)의 패턴으로 요약된다. ㄱ자형은 만기일 이전 1주일 동안 거래활동을 축소하는 패턴이고, L자형은 만기일 이후 1주일 동안 거래활동을 확대하는 패턴이고, U자형은 만기일 이전 1주일과 만기일 이후 1주일 동안 거래활동을 확대하는 패턴이다. 둘째, 개인투자자는 파생상품 life cycle과 관련하여 대형주 종목군을 대상으로 ㄱ자형 거래패턴(선물만기 기준)과 U자형 거래패턴(옵션 단독만기 기준)을 보인다. 이러한 거래패턴은 Foster and Viswanathan(1990)의 전략적 유동성 거래자 모형의 예상과 일치하였다. 셋째, 파생상품 life cycle과 관련하여 외국인투자자의 거래행태는 부분적으로 전략적 유동성 거래자 모형의 예상과 일치하였으나, 기관투자자의 거래행태는 전략적 유동성 거래자 모형의 예상과 무관하였다. 우리나라 주식시장의 전체 거래규모에서 가장 큰 비중을 차지하는 개인투자자가 파생상품의 만기와 관련하여 전략적으로 유동성 거래를 수행한다는 점은 파생상품의 life cycle이 주식시장에 주기적으로 영향을 주는 중요한 경로임을 의미한다. 본 연구는 이러한 경로를 새로이 규명하였다는 점에서 의미를 가진다.

• Journal of Information Technology Applications and Management
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• 제12권4호
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• pp.25-31
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• 2005

We know that the Hurst Exponent (HE) is a real number in [0, 1] which denotes randomness of time series. in this research, we suggest non-linear analysis of human biological signals through HE. The feasibility of human biological signals using inductive incitement provides Some diagnosis for active treatment. In our experiment, we measured the heartbeat through the MCG, 29 healthy and 34 abnormal subjects ostensibly. The raw data of acupuncture incitement are supported by opinions of gross examination and pathological diagnosis. The mean values of HE are 0.345, 0.755 and 0.805 for the periods of before, during and after acupuncture treatment, respectively in case of abnormal subjects. On the other hand, the mean values, 0.808, 0.797 and 0.785 are for normal cases, correspondingly. From this data, we show that HE is very significant in abnormal controls according to an acupuncture incitement, and the incitement effect is evidently extracted in abnormal subjects. But, in normal subjects, the incitement effect is meaningless.