• Korean Journal of Construction Engineering and Management
• /
• v.23 no.1
• /
• pp.89-97
• /
• 2022

Recently, various problems such as reduced productivity, insufficient inflow of skilled manpower, reduced quality, and concerns about increasing safety accidents have appeared in the domestic construction industry. Stakeholder of construction project are considering the Off-Site Construction (OSC) method rather than the conventional on-site construction as an alternative. Despite the importance of decision making in the early stage of the adoption of OSC, there is a lack of methodologies for rational decision making. In this study, a decision making system has been developed to derive the final construction cost score by deriving the project characteristics, selecting the construction difficulty index, and developing a cost model for each construction method alternatives to calculate the standard construction cost. Using this system, the OSC method can be effectively evaluated in terms of its feasibility in the early stage of construction

• Korea Trade Review
• /
• v.48 no.4
• /
• pp.209-232
• /
• 2023

This study aims to estimate the export performance factors of Korean Steel Products to the EU and the expected changes in exports according to the CBAM(Carbon Border Adjustment Mechanism). the factors influencing the export performance of Korean Steel Products to the EU were analyzed using a Gravity Model, and the expected export amount in the case of a Carbon Tax was calculated assuming that the CBAM would be implemented in 2026, As a result, it was empirically analyzed that economic growth, population growth, exchange rate and manufacturing production index of each EU country have a positive effect on exports in Korea, and it was analyzed that the effects of the single market and system due to the EU's economic community were also helpful in increasing exports but the Carbon Tax is imposed in 2026, reducing Korea's steel exports by about -3.6% to -5.7%

• Current Research on Agriculture and Life Sciences
• /
• v.4
• /
• pp.141-153
• /
• 1986

This study intends to document the existing cyclical fluctuations of garic and onion price at farm gate level during the period of 1966-1986 in Korea. The existing patterns of such cyclical fluctuations were estimated systematically by removing the seasonal fluctuation and irregular movement as well as secular trend from the original price through the moving average method. It was found that the cyclical fluctuations of garic and onion prices repeated six and seven times respectively during the same period, also the amplitude coefficient of cyclical fluctuations showed speed up in recent years. It was noticed that the cyclical fluctuations of price in onion was higher than that of in garic.

• Journal of Korea Port Economic Association
• /
• v.30 no.2
• /
• pp.113-132
• /
• 2014

With the global warming phenomenon, the deep sea water area that fishing vessels can enter and operate is ever widening. For example, the Arctic Ocean recently has overall competitive advantages due to having many deep-sea fish stocks. The North Pacific region is a strategic coastal district, the closest access point of Arctic Ocean. For Korean fishing vessels which now operate in North Pacific region, and want to entry the Arctic Ocean, the analysis of technical efficiency is needed for preparing the better industry's future. This paper aims to analyze the relative efficiency, and select the low effective deep-sea fishing vessels in the North Pacific, and to suggest their desirables strategies. As a research methodology, Data Envelopment Analysis (DEA) and Malmquist Index are applied to 16 fishing vessels for the periods(2009 to 2013). To draw out the efficiency of targeted deep-sea fishing vessels, gross tons, horsepowers, and operating days are used as input variables while total catch stands for an output variable. As a result, CCR efficiency, BCC efficiency and scalability efficiency are measured to be 0.8405, 0.9484 and 0.8858 respectively for 5 years (2009 to 2013). In conclusion, 38% of total tons, 36% of horsepowers and 29% of operating days each fishing vessel should be reduced to keep their competitive powers.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.7
• /
• pp.1074-1081
• /
• 2021

Nitrous oxide (N₂O) is one of the six major greenhouse gases and is known to produce a greenhouse ef ect by absorbing infrared radiation in the atmosphere. In particular, its global warming potential (GWP) is 310 times higher than that of CO₂, making N₂O a global concern. Accordingly, strong environmental regulations are being proposed. N₂O reduction technology can be classified into concentration recovery, catalytic decomposition, and pyrolysis according to physical methods. This study intends to provide information on temperature conditions and reaction time required to reduce nitrogen oxides with cost. The high-temperature ranges selected for pyrolysis conditions were calculated at intervals of 100 K from 1073 K to 1373 K. Under temperatures of 1073 K and 1173 K, the N₂O reduction rate and nitrogen monoxide concentration were observed to be proportional to the residence time, and for 1273 K, the N₂O reduction rate decreased due to generation of the reverse reaction as the residence time increased. Particularly for 1373 K, the positive and reverse reactions for all residence times reached chemical equilibrium, resulting in a rather reduced reaction progression to N₂O reduction.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.316-316
• /
• 2020

1970년대 이후 급속한 경제성장과 함께 도시화와 산업구조의 변화로 인간 활동과 밀접한 관계를 맺고 있는 수환경은 크게 훼손되어 왔다. 특히 인간 활동으로 인한 대량 생산과 소비는 하천의 자정작용을 초과하는 오염물질을 배출하고 오염된 하천은 본래 기능을 상실하였으며 각종 생활 오·폐수의 배수구로서의 역할이 부여되어 대부분 복개되기에 이르렀다. 이처럼 현재 우리나라의 하천은 고유의 기능인 용수원으로의 기능과 도시민의 휴식 및 친수공간으로서의 기능을 상실하였으며 중소하천의 건천화에 따른 하천 유지유량의 부족은 하천을 중심으로한 각종 용수의 부족, 수질 오염의 증가, 수변환경 친수기능 상실 등의 문제를 초래하고 있다. 중소하천의 건천화현상은 2000년대 이후 계속 증가, 진행되어 소하천뿐만 아니라 지방하천도 이미 메마르고 있는 상태이며 이로 인한 2차적 비용증가 등 경제적인 측면의 손실도 매년 심해지고 있어 건천화에 대한 원인 규명과 방지책에 대한 연구가 시급한 실정이다. 특히 새만금유역은 농업용수 사용이 많은 유역의 특성상 하천의 건천화 문제가 지적되었으나, 대부분 새만금유역의 용수이용체계 등에 연구가 추진되어 주로 농업용수 이용실태와 수질측정을 위주로 하고 있으며, 건천화의 실태와 원인, 그리고 건천화로 인한 물환경의 영향 등에 대해 조사된 바가 없다. 따라서 본 연구는 만경강유역 하천에 대하여 대조하천, 도시하천, 준도시하천, 농업하천으로 대표지점을 선정하여 현장조사와 유역모델링을 통해 건천화의 원인별 기여율을 파악하였고, 만경강유역의 건천화 규모를 추정하였다. 건천화 원인을 평가하기 위해 유역 내 인위적인 물이용이 없는 상태인 기준유량(자연유량)을 산정하였고, 댐 및 방류량의 영향, 하수처리수 유입에 의한 영향, 수자원이용에 의한 영향, 수리구조물(수자원이용)에 의한 영향의 조건을 고려하였으며 건천화 평가지수를 활용하여 대상하천 소유역의 건천화 현황을 파악하였다. 또한 분석된 결과를 토대로 만경강유역의 토지이용도를 고려하여 만경강유역의 건천화 규모를 추정하였다. 분석결과, 수리구조물(수자원이용)에 의한 영향이 25.5%, 수자원이용에 의한 영향이 13.9%, 방류량에 의한 영향이 12.3%, 하수처리수 유입에 의한 영향이 6.54%로 나타났으며, 수리구조물(수자원 이용)에 의한 영향이 가장 크게 평가되었고, 하수처리수 유입에 의한 영향이 가장 작은 것으로 평가되었다. 이러한 연구결과는 향후 하천의 건천화현상에 대한 원인을 규명하고 방지하기 위한 대책 수립에 필요한 기초자료로 활용이 가능할 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.561-569
• /
• 2020

This study was done to develop indicators for cities that can be used in the long term and in a sustainable manner. Activation indicators were developed to improve the resilience in the downtown area of Seo-gu, Incheon. Preliminary indicators were derived from prior studies on similar indicators of resilience for urban regeneration, and an expert opinion survey was conducted to analyze the suitability and importance of the indicators. Activation indicators were established for improving urban resilience in six areas: population stability, social inclusion, industrial diversity, local productivity, environmental sustainability, and social-based convenience. From 60 preliminary indicators, 42 indicators were selected through the expert opinion surveys for securing an economically active population, establishing a living infrastructure, improving the settlement environment, and upgrading industry to reflect the characteristics of the West, including industrial complexes. It was found that diversification is necessary. Further study is still necessary to improve the objectivity of the indicators and calculate a resilience index. The significance of this study is that it looks at quantitative indicators, complements other studies on regional decline diagnosis, and presents realistic alternatives suitable for domestic situations based on the concept of resilience.

• Journal of Energy Engineering
• /
• v.24 no.2
• /
• pp.9-16
• /
• 2015

As electricity is an indispensable input to human's existence and industrial production, economic benefits arise from consumption. The economic benefits of the electricity consumption are useful information in various fields of electricity-related policy. Therefore, this study attempts to value the economic benefits from electricity use. The economic benefit of electricity consumed is the area under the demand curve which made of the sum of the actual consumer expenditure and the consumer surplus. Consumer expenditure can be easily observed but the information on price elasticity of demand is necessarily required to compute consumer surplus. This study derives the estimates for price elasticities through literature review. The price elasticities of the electricity demand for residence, industry, and commercial are estimated to be -0.332, -0.351, and -0.263, respectively. Because the consumer surplus of the electricity consumption for residence, industry, and commercial are computed to be 191.54, 143.44, and 231.91 won per kWh, respectively. Given that average prices of electricity use were 127.02, 100.70, and 121.98 won per kWh for the year 2013, the economic benefit are calculated to be 318.56, 244.14, and 353.89 won per kWh, respectively. We can convert the values to 321.96, 246.75, and 357.67 won per kWh in 2014 constant price, respectively, using consumer price index. They can be used in the economic feasibility analysis of a new electricity supply project.

• Archives of design research
• /
• v.17 no.3
• /
• pp.111-122
• /
• 2004

The purpose of this study are two the first is to identify the positioning of product design and analyze its functional relationship with product development, manufacturing, marketing and sales in the comprehensive competitiveness evaluation model ; and the second is to estimate the determinants of QCI(quality competitiveness index), analyze the impact of product design on QCI, and compare the aforementioned results for the seven industrial sectors and the five product patterns. For this empirical analysis, this study surveyed 400 Korean manufacturing firms during August-October 2003. The major empirical findings are summarized as follows : First, the hypothesis on the positive effect of product design on QCI is accepted at a highly significant level (p < 0.001) for all : the manufacturing sector, seven industrial sectors, and five product categories. Second, the correlation analysis and factor analysis lead to the result that the effect of product design on QCI is estimated to be relatively very low, in comparison to those of product functionality and basic performance on QCI. These findings imply that Korean manufacturing sector has been still in the prematured stage at which product design has not played an important role yet. This study concludes that product design in line with other functions (product development, manufacturing, marketing, and sales) should make a good contribution to the improvement of QCI in the future.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.1
• /
• pp.20-25
• /
• 2021

The cement clinker, the main raw material of cement, is manufactured using limestone as the main material. Depending on the quality of limestone, the use of subsidiary materials changes, and has a great influence on the production of cement clinkers. In this study, the effect of CaO content of limestone, a cement clinker material, on Raw Mill grinding and sintering of cement clinker was investigated. The grinding time of the union materials changed in the content of limestone CaO was measured to identify the grinding properties. The raw material combination was cleaned within a range of 1,350-1,500℃. The sintering performance of cement clinker by Burnability index calculation was identified. The lower the grade of limestone, the lower the grinding quality of the raw material combination. The lower the CaO content of limestone, the greater the variation in F-CaO for sintering temperature. The lower the class of limestone, the higher B. I. value was calculated, indicating the lower cement clinker sintering. In addition, the mineral analysis results of cement clinker showed that if the F-CaO value was low due to the increase in sintering temperature, the Belite content decreased and the Alite content increased. In the case of Alite, the ratio of R-type decreased and that of M-type increased as the content of limestone CaO increased.