• 자원환경지질
• /
• 제50권6호
• /
• pp.509-515
• /
• 2017

일반적으로 석영은 지각을 구성하는 광물 가운데 가장 많은 부분을 차지하고 있으며, 이러한 석영의 용해와 침전에 대한 이해는 암석의 풍화 매커니즘과 열수작용 및 변성환경에서의 암석과 물의 관계를 규명하는데 매우 중요한 역할을 한다. 본 논문에서는 석영의 용해와 침전에 영향을 미치는 다양한 물리화학적 환경을 수식을 이용해 재정리하였으며, 이전의 연구자들이 발표한 연구결과를 바탕으로 물리화학적 조건하에서의 석영 용해에 대해 이론적 접근을 실시하였다. 본 논문을 통해서 석영의 용해 및 침전이 다양한 환경에 영향을 받으며, 특히 이론적 접근을 통해서 석영에 작용된 압력보다는 주변의 pH 및 온도 조건에 더 큰 영향을 받는다는 것을 확인하였다.

• 대한보건연구
• /
• 제44권4호
• /
• pp.15-24
• /
• 2018

연구목적: 본 연구에서는 경제활동이 활발할 것으로 기대되는 성인 남성군의 흡연량이 객관적인 경제 상황 외에 주관적 경제 인식에 따라 달라지는지를 확인하였다. 연구방법: 통계분석에는 경제적 상황에 대한 전망 변수가 조사된 제 4차 한국복지패널조사(KoWEPS) 자료를 사용하였으며, 근로능력을 갖추고, 결혼 이력이 있는 30세-54세 기혼 남성에 대해 매개효과 확인을 위한 3단계 회귀분석을 실시하였다. 연구결과: 경제적 상황은 경제적 인식에 직접적인 영향을 주는 것으로 나타났다(1단계). 경제적 전망에 대한 부정적 인식은 흡연량과 정적인 관계에 있었고(2단계), 가구의 가처분소득은 다만 경제적 전망을 통해서만 흡연량에 영향을 주는 것으로 나타났다(3단계). 이를 통해 경제적 상황은 청 장년층 흡연량에 대해 경제적 인식을 통한 매개 효과를 가지는 것을 확인할 수 있다. 결론: 구매력이 충분한 청 장년층 남성 인구집단에서 열등한 경제적 지위는 이와 관련된 부정적 인식과, 우려 그리고 스트레스 등을 통해서 흡연에 영향을 준다. 따라서 이들 집단에 대해서는 가격적 정책의 효과가 상대적으로 낮게 나타날 가능성을 시사하며 비가격적 정책이 함께 실시되어야 할 필요성을 보여준다.

• 한국안전학회지
• /
• 제10권4호
• /
• pp.60-67
• /
• 1995

Ocassionally, many chemical plants experienced unexpected shutdown and suffered serious economic loss caused by boiler accidents due to mis-operations during the start-up or shutdown. A strategy to prevent such accidents is proposed here by using the form of frame for the recognition of all needed conditions, i.e., the states of the boiler, hazardous or dangerous conditions, each level conditions, transition network and heuristic knowledge of human operators. The expert system based on this strategy is considered to be an available method to predict all of the hazardous conditions in boiler plants.

• 한국경제지리학회지
• /
• 제10권1호
• /
• pp.1-18
• /
• 2007

본 연구에서는 개방경제체제로 전환되는 과정에서 울산이 가질 수 있는 시스템 전환의 가능성에 기초해서 울산 자동차클러스터의 발전방향을 탐색하고 바람직한 전략적 개입의 방향을 제시하고자 했다. 울산의 자동차 클러스터의 조건을 탐색하기 위해 생산 및 연구개발 네트워크의 글로벌 차원, 국가 차원, 지역 차원의 공간적 특성에 대하여 분석하였다. 그리고 현대자동차가 울산공장을 설립하면서 시작된 울산의 자동차 산업의 집적과정의 특징과 그 동안 축적한 역량에 대한 분석에 기초해서 대안적 발전경로를 탐색하고 정책적 시사점을 도출하였다.

• 산업공학
• /
• 제13권1호
• /
• pp.100-109
• /
• 2000

This paper presents an economic analysis for alternatives of the building telecommunications cabling system to accommodate multimedia services. Four alternatives are developed with respect to capacities of the building telecommunications cabling systems. Economic analysis includes qualitative analysis as well as quantitative one and the results of those analyses are incorporated with AHP(analytic hierarchical process) method. In analyzing the alternatives, based on the possible growth of multimedia traffic and evolution of access networks, various scenarios are considered. The results suggest not only the most competitive alternative but also the conditions for each alternative to gain the competitive edge.

• 한국항만경제학회지
• /
• 제21권4호
• /
• pp.161-181
• /
• 2005

This paper investigates the circumstances and conditions of Mokpo Port to develop it as an international logistics stronghold and seeks scheme to maximize the local economic ripple effect through construction and activation of Mokpo New Port. Under the circumstances in which neighboring ports vying with each other have built broad spheres of influence, and competition among ports becomes fierce, a priority cargo attraction strategy should be established by using Mokpo's favorable location compared to other ports in order to ensure that a large quantity of goods is transported from Mokpo New Port. Especially, Mokpo New Port needs to be developed as a vehicles-only exporting port, as well as a port for used car exports and an import port for stones and timber.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
• /
• pp.115-117
• /
• 2007

This paper presents a new systematic approach to find a global solution to economic dispatch (ED) with multiple fuel units using a function merger (FM). Currently, no systematic approach has been developed to find a global solution to economic dispatch with multiple fuel units. Various heuristic methods have been proposed, however it is almost impossible to guarantee a global solution by those methods yet. The proposed method uses the FM and $\lambda$-P functions. A FM merges several fuel cost functions into one that satisfies the optimal conditions of an ED. The FM procedures are described in detail with illustrative examples.

• Structural Engineering and Mechanics
• /
• 제47권2호
• /
• pp.287-305
• /
• 2013

Economic performances of consecutive multi-span suspension bridges are studied. The material amount and cost estimation formulas of the bridges have been derived in the part 1 of the study. A parametric study is carried out based on the formulas for investigating the different factors' effect on the bridge cost. The factors include the bridge sag, the bridge span, the bridge foundation and the environment condition, etc. Then, an economical layout of the bridges is proposed for different conditions. Lastly, a selection of suspension bridge types is discussed based on the economy of bridges.

• East Asian Economic Review
• /
• 제19권1호
• /
• pp.39-70
• /
• 2015

This paper examines the effects of foreign direct investment (FDI) on South Asian economies' output growth, utilizing recent panel cointegration testing and estimation techniques. Annual panel data on eight SAARC (South Asian Association for Regional Cooperation) member countries' macroeconomic variables over the period 1960- 2013 are employed in empirical analysis. Using various heterogeneous panel cointegration and panel causality tests, a bi-directional relationship between FDI and growth is found. We find evidence for both FDI-led growth and growth-induced FDI hypotheses for the South Asian economies over the sample period. Individual member countries exhibit heterogeneity in terms of the direction or existence of causality subject to their idiosyncratic economic conditions. Among various regressors, FDI, financial development, human capital, and government consumption show the most significant positive effects on output growth. As determinants of FDI, GDP, financial development, human capital, and government consumption are found significant in the region. The bi-directional causality between FDI and growth is found robust to the inclusion of other control variables and using different estimation techniques.

• 동력기계공학회지
• /
• 제17권1호
• /
• pp.19-26
• /
• 2013

The purpose of the study is carried out volume optimization of a combined system consisting of an LNT and SCR catalysts from the standpoint of its economic feasibility and de-NOx performance. Under the rich air-fuel ratio conditions for 5s (${\Phi}$=1.1), CO, $H_2$ and THC were generated at levels of 4%, 1.2% and $110ppmC_1$, respectively. The NOx conversion of the 1+1 combination was 5% lower than that of the 1.5+0.5 combination, however the reduced volume of the LNT catalyst decreased the total cost by about 6%. Therefore, the optimal volume ratio of the LNT and SCR catalysts was found to be the 1+1 catalyst combination, which has the highest total score in the terms of an economic feasibility and the NOx performance.