• 대한환경공학회지
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• 제27권4호
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• pp.409-413
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• 2005

본 논문에는 자가영양균의 최대비성장율 추정법이 제시되었다. 먼저 질산화균의 농도가 질산화 된 암모니아, 슬러지 일령 및 사멸계수를 이용하여 시뮬레이션 되었고, 다음단계로 과잉암모니아를 공급하여 질산화균의 호흡율을 측정하였다. 자가영양균의 최대비성장율은 ${\mu}_{max,A}\;=\;OUR_{max,A}/Y_A$의 관계를 통해 계산되어질 수 있으며 추정된 최대비성장율은 운전기간에 걸쳐 일정한 값을 가지지 앉고 시간에 따라 변화한다는 결과를 얻었다. 본 연구를 통해 최대호흡율을 이용한 최대비성장율의 동적 추정법이 수행되었고, 일정한 최대비성장율를 이용한 처리장 운전결과 예측은 처리장 거동을 예측할 수 없으며 활성슬러지공정의 성능예측을 위한 시뮬레이션을 위해서는 동적 추정된 매개변수의 사용이 필요함을 확인하였다.

• 터널과지하공간
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• 제20권2호
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• pp.125-130
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• 2010

화약류를 이용한 발파에서 가이드공의 균열제어효과를 검토하기 위하여 모르타르 공시체를 이용한 발파실험을 수행하였다. 모르타르 블록의 중앙에 장약공을 설치하고 주변에 방사상으로 4종류의 가이드공을 각각 두 개씩 설치하였다. 4종류의 가이드공은 원형, 노치형, 다이아몬드형, 다이아몬드 홀더형이며, 장약공과 가이드공의 간격은 각각 110 mm, 165 mm, 220 mm으로 하여 3가지 형태의 모르타르 공시체를 제작하였다. 발파 실험 후 공시체에 대한 분석결과, 적용된 가이드공 모두 균열제어효과를 보였으며 같은 폭발압력에서는 노치 가이드 공이 보다 높은 균열제어효과를 나타내었다.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.113-122
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• 2021

This study aims to investigate the effects of fiscal policy instruments on economic growth in Jordan using annual data from 1970 to 2019, by applying the VAR model (Vector Auto regression) and the Vector Error Correction Model (VECM). The study also examines the dynamic relationship among economic variables over time using the Granger casualty test, Impulse Response Function, and Variance Decomposition. The results show that not only the public expenditures have a positive effect on economic growth in Jordan, but also the tax revenues positively affect the economic growth in the short-run, and this is because of using the tax revenues to finance the government activities in Jordan. This effect becomes negative in the long run, and this is explained because the tax seems a source of distortions in the economy, The extreme taxes may cause huge distortions in the economy, and these distortions destroys the purchasing power, the aggregate demand, and supply. More governmental dependence on tax revenues is the main source of tax evasion and less efficiency. The effect of taxation will curb any prosperity in the economy. Therefore, the government should estimate the fair tax rates to generate sufficient revenues to finance the public expenditure required to enhance economic prosperity.

• 임산에너지
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• 24권2호
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• pp.37-45
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• 2005

본 연구에서는 동적생장모델을 이용하여 산림경영(간벌작업)의 수행여부에 따른 산림의 재적변화량, 산림의 바이오매스와 탄소흡수량을 추정하였다. 간벌 수행 여부에 따른 산림의 재적 변화량을 추정한 결과, 간벌을 수행하였을 경우의 산림 재적 변화량이 현저히 높게 추정되었으며, 이로 인한 산림의 탄소흡수량의 차이도 매우 크게 추정되었다. 간벌이 이루어지지 않은 산림에서의 탄소흡수량은 0.27tC(탄소톤)/ha로 추정되었으며, 간벌이 이루어진 산림에서는 166.02tC(탄소톤)/ha(상층간벌), 163.75tC(탄소톤)/ha(하층간벌)로 각각 추정되었다. 따라서 간벌은 산림의 탄소흡수량 증진에 매우 큰 영향을 미치는 것으로 판명되었으며, 각 간벌유형별 탄소흡수량은 큰 차이를 나타내지 않았다. 따라서 산림의 탄소흡수 및 탄소흡수량 증진을 위해서는 간벌작업을 통한 산림경영이 필수적인 요소라고 판단된다.

• Journal of Information Processing Systems
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• 제5권1호
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• pp.33-40
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• 2009

Ever since the network-based malicious code commonly known as a 'worm' surfaced in the early part of the 1980's, its prevalence has grown more and more. The RCS (Random Constant Spreading) worm has become a dominant, malicious virus in recent computer networking circles. The worm retards the availability of an overall network by exhausting resources such as CPU capacity, network peripherals and transfer bandwidth, causing damage to an uninfected system as well as an infected system. The generation and spreading cycle of these worms progress rapidly. The existing studies to counter malicious code have studied the Microscopic Model for detecting worm generation based on some specific pattern or sign of attack, thus preventing its spread by countering the worm directly on detection. However, due to zero-day threat actualization, rapid spreading of the RCS worm and reduction of survival time, securing a security model to ensure the survivability of the network became an urgent problem that the existing solution-oriented security measures did not address. This paper analyzes the recently studied efficient dynamic network. Essentially, this paper suggests a model that dynamically controls the RCS worm using the characteristics of Power-Law and depth distribution of the delivery node, which is commonly seen in preferential growth networks. Moreover, we suggest a model that dynamically controls the spread of the worm using information about the depth distribution of delivery. We also verified via simulation that the load for each node was minimized at an optimal depth to effectively restrain the spread of the worm.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 1995년도 추계학술대회 발표요약문
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• pp.9-21
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• 1995

계획지원체계는 도시성장관리수단으로 간선시설 시설확장을 이용하는 우리의 능력을 증진시킨다. 이연구는 그러한 계획지원체계 (PEGASUS: 공간도시체계의 생성 및 분석을 위한 계획환경)의 개발계획의 일환으로서 상수도 시설확장모델의 개발에 관한 연구이다. 이 연구는 토지이용과 개발은 간선시설의 수요를 유발하고 간선시설은 토지가 이용되고 개발되는 방향에 영향을 미친다는 전제하에서 시작된다. 상수도 시설 확장은 2 방법으로 해결될 수 있다: 1) 최적통제이론, 2) MINLP 방법. 이 방법들은 각각장단점을 가지고 있다. 이 연구에서는 동적 시설 확장 크기 및 시기를 동시에 결정할 수 있는 MINLP방법이 채택이 되었다. 상수도 관망해석모델과 동적 상수도 시설 최적화 모델이 상수도계획과 토지이용계획의 동적 연관관계를 해결할 수 있다. 상수도 관망해석모델은 생성된 관경의 적정성을 분석하며 동적 상수도 시설 최적화모델은 변화하는 상수도 수요량을 충족할 수 있는 대안을 작성한다. 표준화기법에 의한 비용편익분석은 가장 경제적인 대안을 선정한다. GIS는 필요 상수도 수요량을 산정하고 시설확장모델의 결과를 이용자에게 보여주는데 훌륭한 역활을 할 수 있다.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.45-52
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• 2021

The capital structure is one of the hot financial topics among researchers and scholars. Its importance comes from the fact that capital structure is closely related to companies' ability to meet different stakeholders' needs. A suitable capital structure will boost the business and create a competitive advantage in the context of fierce competition. Many companies choose an optimal debt level based on the trade-off between interest and debt costs. This study aimed to test the existence of trade-off theory in capital structure, the case of Vietnam's real estate companies, which are growing very fast recently. Instead of considering constant optimal leverage to test the trade-off model, we take advantage of the dynamic capital structure determined by growth opportunities, profitability, tax incentives, tangibility, liquidity, and firm size. The dynamic panel data regression was estimated by the system Generalized Method of Moment (Sys-GMM). The empirical evidence showed that real estate companies listed in the Vietnamese stock market might change their leverage toward a target capital structure determined by influential factors in a long-term perspective. In particular, the debt-to-asset ratio will change by approximately 14 percent, positively, in response to the difference between the current debt-to-asset ratio and the dynamic target debt-to-asset ratio.

• 품질경영학회지
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• 제33권4호
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• pp.21-41
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• 2005

This study analyzes the Internet utilization pattern of customer by comprehensively investigating the previous studies on the behavior pattern of customer in terms of Internet business. Based on the analysis, this study develops research framework that supports strategic decision-making for resource allocation in Internet business. Such research framework would be helpful for providing the typology of Internet business model that can be specialized by each industry. As a result of the simulation analysis, it was found that the optimal resource allocation portfolio providing maximum profits to the Internet bookstore involves large-scale investment on delivery service and customer support service which are the key factors for post-purchase customer satisfaction, regardless of the growth pattern or size of Internet bookstore market. Consequently, from the above analysis, the investment ratio of resources for the profit maximization of Internet bookstore was drawn. Conclusively, based on the comprehensive examination of the results, this study provided a framework for dynamic resource allocation decision-making, and proposed a management strategy which allows consumers to shop under more favorable environment, and simultaneously enables the Internet bookstore to accomplish management objectives such as continuous growth and profit maximization.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.829-837
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• 2021

The study investigates the impact of the Counter-Cyclical Buffer Policy (CCB) on regional development bank profitability in Sumatra, Indonesia. CCB requires banks to hold capital at times when credit is growing rapidly so that the buffer can be reduced if the financial cycle turns down or the economic and financial environment becomes substantially worse. This study employs time series data of regional development banks (RDBs) in Sumatra Island, Indonesia. The methodology applied in this study is a panel dynamic model with Generalized Methods of Moments (GMM). The results show that increasing capital through the implementation of CCB did not have a significant effect on RDBs' profitability. The findings of this study suggest that the activation and implementation of CCB lead to an increase in the amount and cost of loans to companies but do not affect the profitability of RDBs. The value of a Non-Performing Loan (NPL) proved to have a negative and significant effect on bank profitability. The CCB policy aims to overcome the pro-cyclicality of credit growth and improve bank resilience through increased capital which is expected to reduce excessive credit growth as a source of systemic risk. This causes a lack of lending to the community so that the profits obtained by the bank decrease.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권1호
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• pp.31-50
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• 2023

In the midst of dynamic industrial changes, companies need data analysis considering the effects of integration of various technologies in order to establish innovative R & D strategies. However, the existing technology forecasting model evaluates individual technologies without considering relationship among them. To improve this problem, this study suggests a new methodology reflecting the integration of technologies. In the study, a technology forecasting indicator was developed using the technology integration index based on social network analysis. In order to verify the validity of the proposed methodology, 'drone task performance technology' based on patent data was applied to the research model. This study aimed to establish a theoretical basis to design a research model that reflects the degree of integration of technologies when conducting technology forecasting research. In addition, this study is meaningful in that it quantitatively verified the proposed methodology using actual patent data.