• 한국정밀공학회지
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• 제17권9호
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• pp.196-201
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• 2000

There is a great demand for reducing the amount of material used in mass-produced plastics parts for material cost constitutes a large percentage of the total cost of a product up to 75% It may be noted that the price of plastics is directly related to the price of petroleum. Material reduction therefore decreases the amount of oil needed for the manufacture of plastics and thus help conserve this natural resource. Therefore microcellular foaming process(MCPs) was studied for solving this problems alternatively in 1980's at M. I. T. Until now in microcellular plastics processes carbon dioxide gas was mainly used for microcellular foaming Because carbon dioxide has more solubility than any other gases such as nitrogen gas or helium gas. The purpose of the this research is measurement of changing of the microcellular plastics' weight by using nitrogen gas in injection molding an comparing weight reduction of microcellular foamed plastics for using carbon dioxide gas with nitrogen gas.

• 기술혁신연구
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• 제4권1호
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• pp.1-26
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• 1996

Traditional studies of new venture performance have focused on the characteristics of entrepreneurs and have shown conflicting results on the relationship between the characteristics and performance of new ventures. Recently, some researchers have broadened their search to include aspects of the industry and the strategy of new ventures. The purposes of this study are to identify wtrategic archetypes of new ventures based on the taxonomic approach and to explain the differences in new venture characteristics and performance among strategic archetypes. To find the strategic archetypes, 114 new venture CEOs from various industries were asked to describe their ventures' competitive strategy through 19 questionnaire items on competitive methods. Using factor analysis and subsequent cluster analysis, four archetypes were identified such as : versatile type, technology-driven type, market-oriented type, and cost reduction type. The results imply that there exist different types of venture strategy even among new technology-based venture firms in Korea, and show the differences in performance among strategic archetypes: market-oriented type and versatile type are better than cost reduction type in terms of growth rate and profitability. Because the venture strategy in identified as a major determinant of the venture performance in this study, the choice of venture strategy suitable for firm's industrial characteristics and internal resource bases becomes a very strategic decision for firm's sustained growth. Further studies are needed to strengthen some methodological limitations of the study.

• 한국IT서비스학회지
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• 제16권3호
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• pp.1-15
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• 2017

This study is aimed to find out which factors among firm-specific resources, industry-based competition, and institutional conditions affect strategies for Korean IT manufacturing companies when they expand their business overseas, especially to Vietnam in this study. Also, it attempts to reveal which strategies among cost reduction, mass production, and localization affect performance of overseas expansion. Based on Strategy Tripod Theory as an integrating point-of-view embracing resource-based view, industry-based view, and institution-based view, research model was developed and tested through the survey of 83 Korean IT manufacturing companies expanded their business to Vietnam. Research findings show that (1) communication competency, industry competitiveness, industry attractiveness, and regulation of partner country affect cost reduction strategy. (2) International experience, communication competency, international orientation, and competitiveness is significantly associated with mass production strategy. (3) And international experience, communication competency, and industry competitiveness affect localization. (4) Ultimately, mass production strategy and localization strategy significantly increase performance of expansion to Vietnam. The theoretical contribution of this study is to adopt an integrative approach based on strategy tripod theory. As practical implications, it suggests factors and strategies that IT manufacturing companies interested in expansion to Vietnam should consider. In sum, we believe this study can contribute to Korean IT manufacturing industry by suggesting key success factors and appropriate strategies for overseas expansion.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2680-2700
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• 2017

Finite field arithmetic over GF($2^m$) is used in a variety of applications such as cryptography, coding theory, computer algebra. It is mainly used in various cryptographic algorithms such as the Elliptic Curve Cryptography (ECC), Advanced Encryption Standard (AES), Twofish etc. The multiplication in a finite field is considered as highly complex and resource consuming operation in such applications. Many algorithms and architectures are proposed in the literature to obtain efficient multiplication operation in both hardware and software. In this paper, a modified serial multiplication algorithm with interleaved modular reduction is proposed, which allows for an efficient realization of a sequential polynomial basis multiplier. The proposed sequential multiplier supports multiplication of any two arbitrary finite field elements over GF($2^m$) for generic irreducible polynomials, therefore made versatile. Estimation of area and time complexities of the proposed sequential multiplier is performed and comparison with existing sequential multipliers is presented. The proposed sequential multiplier achieves 50% reduction in area-delay product over the best of existing sequential multipliers for m = 163, indicating an efficient design in terms of both area and delay. The Application Specific Integrated Circuit (ASIC) and the Field Programmable Gate Array (FPGA) implementation results indicate a significantly less power-delay and area-delay products of the proposed sequential multiplier over existing multipliers.

• 대한원격탐사학회지
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• 제34권1호
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• pp.141-150
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• 2018

Crop type classification is essential for supporting agricultural decisions and resource monitoring. Remote sensing techniques, especially using hyperspectral imagery, have been effective in agricultural applications. Hyperspectral imagery acquires contiguous and narrow spectral bands in a wide range. However, large dimensionality results in unreliable estimates of classifiers and high computational burdens. Therefore, reducing the dimensionality of hyperspectral imagery is necessary. In this study, the Random Forest (RF) classifier was utilized for dimensionality reduction as well as classification purpose. RF is an ensemble-learning algorithm created based on the Classification and Regression Tree (CART), which has gained attention due to its high classification accuracy and fast processing speed. The RF performance for crop classification with airborne hyperspectral imagery was assessed. The study area was the cultivated area in Chogye-myeon, Habcheon-gun, Gyeongsangnam-do, South Korea, where the main crops are garlic, onion, and wheat. Parameter optimization was conducted to maximize the classification accuracy. Then, the dimensionality reduction was conducted based on RF variable importance. The result shows that using the selected bands presents an excellent classification accuracy without using whole datasets. Moreover, a majority of selected bands are concentrated on visible (VIS) region, especially region related to chlorophyll content. Therefore, it can be inferred that the phenological status after the mature stage influences red-edge spectral reflectance.

• 유기물자원화
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• 제22권2호
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• pp.11-16
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• 2014

육상식물 재배면적과 바이오매스 자원이 부족한 우리나라는 바이오 에너지 원료의 다변화가 시급하며, 3면이 바다로 싸여 자원이 풍부한 해양환경을 이용한 바이오 에너지 생산기술 및 이를 통한 $CO_2$ 저감 방안은 매우 효과적인 대안이 될 것이다. SSaM-GG를 통해 $CO_2$ 흡수율이 높고 해바라기의 30배 많은 양의 기름 추출이 가능한 해조류의 바이오 에너지화에 대한 지속가능한 발전을 기대한다.

• Advances in Energy Research
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• 제5권3호
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• pp.207-217
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• 2017

Energy consumption in agriculture is responsible for greenhouse gas emission but it can be reduced after efficient utilization of energy inputs. Therefore, the present study aims for the estimation of energy efficiency and extent of greenhouse gas reduction after benchmarking of inefficient farms in off-season tomato in Punjab province of Pakistan. Primary data were collected from 70 farmers with simple random sampling. By using data envelopment analysis, the average value of technical, pure technical and scale efficiency was 0.80, 0.92 and 0.87, respectively while increasing, constant and decreasing return to scale was observed in 33, 26 and 11 farmers, respectively. Total input energy was reduced by $12,688.91MJ\;ha^{-1}$ (13.89%) if inefficient farms used the energy inputs according to recommendations or benchmarking. A major portion of energy saving comes from fertilizers (68.79%) followed by diesel (15.70%), chemicals (5.91%), machinery (4.37%) and water (4.00%). Total greenhouse gases reduction was $499.17kg\;CO_2\;eq.ha^{-1}$ (14.57%) as a result of improvement in energy efficiency or benchmarking of inefficient farms. Agricultural extension staff should visit the vegetable farms on regular basis and give necessary information about efficient utilization of energy inputs. The government should create awareness about the optimum use of input through seminars and pamphlets.

• 수산경영론집
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• 제42권2호
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• pp.97-112
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• 2011

The coastal and offshore fishery to manage from a fishery permit system in our country at present seems to be a sign of lots problem, which are illegal fishing, a permit rent, non fishing vessel the purpose of vessel reduction, fishery compensation, tax exemption oil, the excessive occurrence of administrative cost due to differences during a period of a fishery permit. All the readjustment system for the permit has suggested an effective solution for a fishery permit management, the maintenance of a fishery order(the prevention of illegal fishery), the prevention of unused fishery, the entrance of new vessel in coastal fishery and it's system has prevent this problems in ahead. This paper has estimated an prevention convenience for an illegal spill of the tax exemption oil, actual effects of vessel reduction, the conservation of fishery resource for the future value and carried out an economic analysis to estimate compliance cost for the system introduction. Also, this study have analyzed throughly the coastal fishery situation and catched lots of issues on the management for the permit system. Especially, the problems improving the readjustment introduction for the permit have estimated the social and economic effects quantitatively and qualitatively with a calculated technique to classify various scenarios. This paper has judged correctly the term of validity for the permit to shorten as a result of the estimation and it will be to take the net convenience cost 1,655thousand million won. The results of this study have expect to provide a basic data to introduce the readjustment system for the permit.

• Membrane and Water Treatment
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• 제6권6호
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• pp.451-476
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• 2015

Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving the energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum-cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo steady state approach for equipment sizing and the dynamic optimization using overall system mathematical models. The s-SMDDS employing three MD configurations, including the air gap (AGMD), direct contact (DCMD) and vacuum (VMD) types, are optimized. The membrane area of each system is $11.5m^2$. The AGMD system operated for 500 kg/day water production rate gives the lowest unit cost of $5.92/m^3$. The performance ratio and recovery ratio are 0.85 and 4.07%, respectively. For the commercial membrane employed in this study, the increase of membrane mass transfer coefficient up to two times is beneficial for cost reduction and the reduction of membrane heat transfer coefficient only affects the cost of the DCMD system.

• 한국주거학회논문집
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• 제23권4호
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• pp.11-18
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• 2012

The amount of energy consumption in the buildings is approximately 20% of domestic energy consumption. The Carbon Point Program have been published on reduction of greenhouse gas emission in buildings under the paradigm of 'Low Carbon Green Growth'. This study focuses on the effect of 'Carbon Point Program' for residential buildings in Daegu. The amount of electricity and waterwork consumption and information of households were investigated to analyse the effect of carbon point program. The samples are situated in Deagu and are apartment in Bukgu and Suseonggu. The $CO_2$ emission is analysed by factors of energy resource and household organization between before participating and after participating in Carbon Point Program. The participation type has a difference of voluntary participation in Suseonggu and passive participation in Bukgu. Based on this investigation, average amount of $CO_2$ emission was reduced from voluntary participation households but all of them did not. To promote the effect of Carbon Point Program, this study proposes that needing the plans to raise will and activity of reducing carbon and to help participation which have disadvantage against achieving reduction.