• New & Renewable Energy
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• v.1 no.2 s.2
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• pp.53-59
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• 2005

Objective of the research is to demonstrate solar thermal space and ground heating system which is integrated to a green-house culture facility for reducing healing cost, Increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Field test for the demonstration was carried out in horticulture complex In Jeju Island. Medium scale solar hot water system was installed in a ground heating culture facility. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Short term day test on element performance and Long term test of the whole system were carried out. Optimum operating condition and its characteristics were closely Investigated by changing the control condition based on the temperature difference which Is the most important operating parameter For establishing more reliable and optimal design data regarding system scale and operation condition, continuous operation and monitoring on the system need to be further carried out. However, It is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.3-10
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• 2019

The entire duration of the long-term continuous construction contract project cannot be expected when calculating the initial budget as the construction of the contract is carried out annually according to the budget composition. In addition, the statutes related to the defect liability and execution of contracts have not been established systematically in relation to the contract. Therefore, there are many problems at the actual construction site with regard to the defect liability or the performance of the contract in relation to the contract. In this study, the following improvement directions were presented for the efficient operation of the contracts: First, the defect liability is legal and should be specified in an Act rather than an enforcement decree. Second, if the parties to the contract vary in the following order in the contract, the special agreement should be specified in the enforcement decree. Third, in the event of an indirect cost due to the extension of the period of the long-term continuous work, the contingency items of the total project cost management policy should be utilized. Fourth, in the case of general construction contract conditions, clauses related to the purchase of the premium of the CAR, inspection, taking over, defect repair, and defect inspection shall be supplemented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.52-63
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• 2019

Biased performance implications are common in conducting empirical analysis on leading firms in strategic management field. Venture businesses in which successful and failing firms in the future are mixed in the present could provide a better discriminative result for examining the determinants of performance. We suggest hypotheses on how competitive strategy, CEO characteristics, and their interactions affect firm performance. We examine these hypotheses through empirical analyses on the basis of a survey collected from 387 venture businesses in order to assure the validity of strategic management theories by using more deviated data. Empirical results show that innovative differentiation from competitive strategies affects firm performance and innovativeness and long-term orientation from CEO characteristics affect firm performance. According to the results of the interaction analyses between competitive strategies and CEO characteristics, cost-leadership and marketing differentiation strategies have combination effects with risk taking, innovativeness, and long-term orientation, while innovative differentiation strategy has no combination effects with risk taking, innovativeness, and long-term orientation. We conclude that cost-leadership and marketing differentiation strategies have no direct effect on firm performance but have combination effects with CEO characteristics, while innovative differentiation strategy has direct effect on firm performance but has no combination effect. Our primary contribution is that we test and confirm that the fit between competitive strategies and CEO characteristics are an important consideration to increase firm performance in venture businesses.

• IE interfaces
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• v.17 no.spc
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• pp.122-130
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• 2004

Since the cost of software maintenance occupies about 50~75% in a general successful organization, the software maintenance plays an important role in software life cycle. In particular, if the managed system needs to be operated in a long term or the system is very large and complex, then the maintenance is especially more important. Software maintenance is defined as software modification activities after customer delivery, such as improvement of performance or functionality, error correction, adaptation to environmental changes, etc. In this paper, software cost estimation models are proposed, that is based on productivity of manpower in maintenance projects. In order to do this, the activities of maintenance are classified into function change, non-function change, user support and application operation. The proposed models are constructed and verified based on the real size and cost information of projects in the real world. The approach in this paper is to discriminate the heterogeneous activities in maintenance projects, and then to calculate the respective cost of each discriminated activity. By using the proposed models, the total cost of maintenance project is summed from the costs of four activities. In addition the number of conflicts between owner and order receiver about the amount of cost will be reduced and the reasonable cost estimation system will be established.

• Journal of Agricultural Extension & Community Development
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• v.11 no.2
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• pp.251-265
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• 2004

The agricultural sector's economic structure in Korea is regarded to encounter major barriers on the way toward revitalizing its economic prosperity. Among many, the energy-related problem is one of prime nuclei embedded in the country's agricultural sector. The ought-to-come structural changes in the country's agricultural energy system hinge upon the central government's policy direction as well as efforts of local governments and local farming community members. The indirect aids via 'cross subsidy' of electricity tariff rate and 'tax-exempt price' of oil fuels are two notable causes of the unsustainable energy consumption pattern in the country's agricultural sector. As measures, demand-side management(DSM) and energy-efficiency promotions are regarded to be the most attractive methods for energy conservation and economic productivity as well. Development of renewable energy sources are also receiving a great deal of attention for the long-term alternatives to the country's existing oil-based agricultural production mode. This study examines the contributive potential of DSM approaches and renewables-based technologies. With the critical evaluation on the concurrent adversities of the country's agricultural energy system, various sources of renewable energy-solar power, wind power, biomass, etc.-are examined for the purpose of technological and economical viability. As sufficient potentials of renewable energy sources are being estimated, both the system production cost and the installation cost for the county's rural areas are expected to lower in the long term. DSM options are also evaluated to be fruitful even in the short term. Both the public and civil arenas must galvanise each side's effort in order to promote these policy options and community potentials.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.4
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• pp.203-221
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• 2017

This study is to suggest some improvement directions of the criteria for the management evaluation in order to contribute to the achievement of lasting value of the continuous development and publicity in regard to the public library means-efficiency. To this end, This study analyzed the means-efficiency evaluation criteria via theoretical review on business analysis of private enterprise and the analysis framework based on it. The improvement of evaluation criteria in regard to efficiency for the continuous development of public library are as follows. 1) Regardless of domestic and foreign, an efficiency index in the performance evaluation index of public library is absolutely insufficient. The sufficient indexes measuring efficiency which is appropriate for the concept of performance should be developed. 2) A flow data representing input and performance in certain time period is insufficient. Therefore, evaluation index consisted of flow data should be more developed. 3) Long term stock data is excluded in the term cost as it is the cost used for the long term such as fixed assets. However, it is useful as input data, which is realized through the perfect accounting.

• Journal of Korean Society for Quality Management
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• v.10 no.2
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• pp.2-9
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• 1982

In principle the methods of increasing the reliability of complex system can be classified into the following four basic methods: (1) using the stand-by redundancy; (2) decreasing the failure rate of the system; (3) decreasing the time of continuous operation; (4) decreasing the mean repair time. Among the above four methods, it is generally known that the method of stand-by redundancy is the most effective general, to increase the reliability of systems. Therefor this paper aims to compare the gain in reliability which is achieved by applying stand-by redundancy with other methods, and to show the characteristics of each method From the comparison of the methods of increasing reliability, the following important facts are found: When the method of stand-by redundancy is used to increase the reliability of complex systems intended for long-term operation, a hight multiplicity of stand-by redundancy is required. Thus an increase of the reliability of complex system by applying stand-by redandancy is realized at the expense of characteristics such as weight, size, cost, increased complexity of operation conditions. And this property restricts its use in systems which are critical with respect to weight, size, cost or operation conditions. The method of stand-by redundancy is the most effective when this method is used to increase the reliability of complex systems intended for short-term operation, and the method of decreasing failure rate is the most effective when it is used to increase the reliability of systems intended for long-term use. The methods of increasing reliability discussed in this paper make it possible to make highly reliable systems. But it is not possible to make a highly reliable system using a single method of increasing reliability, even if it is the most effective one. Therefore it is recommended to use all or a majority of the above four methods by choosing it in accordance with the properties of the system under construction.

• Journal of Korean Academy of Nursing Administration
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• v.20 no.1
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• pp.117-127
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• 2014

Purpose: In order to provide a systematic and standardized treatment course for MVD patients, a critical pathway (CP) program was developed and the results of its long term application were analyzed. Methods: This was a methodological study. The CP was established and applied to 75 (step I) and 1,216 (step II). Another group of 56 with similar features was used as a control group. Results: The application of CP turned out to be useful in many regards: the rate of hearing loss was reduced from 1.8% to 0% (step I) and 0.5% (step II), and low cranial nerve palsy was reduced from 1.8% to 1.3% and 0.7%, respectively. The length of hospitalization decreased by 2.56 days (25.2%) for step I and 3.05 days (30.0%) for step II. Days of ICU stay were reduced by 7.9% and 1.8%. The total cost per patient was reduced by 14.8% (step I). The cost per day was increased by 13.7% and 52.4%. An increase in the patient satisfaction index was noted, as shown in the ICU information guide (p=.002). Conclusion: The development and application of CP was found to improve the quality of medical treatment and the efficacy of hospital management in MVD patients. Well organized and efficient system and multidisciplinary teamwork are the key component of the successful application of CP.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.535-543
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• 2019

Building on/with expansive soils with no treatment brings complications. Compacted expansive soils specifically fall short in satisfying the minimum requirements for transport embankment infrastructures, requiring the adoption of hauled virgin mineral aggregates or a sustainable alternative. Use of hauled aggregates comes at a high carbon and economical cost. On average, every 9m high embankment built with quarried/hauled soils cost $12600MJ.m^{-2}$ Embodied Energy (EE). A prospect of using mixed cutting-arising expansive soils with industrial/domestic wastes can reduce the carbon cost and ease the pressure on landfills. The widespread use of recycled materials has been extensively limited due to concerns over their long-term performance, generally low shear strength and stiffness. In this contribution, hydromechanical properties of a waste tyre sand-sized rubber (a mixture of polybutadiene, polyisoprene, elastomers, and styrene-butadiene) and expansive silt is studied, allowing the short- and long-term behaviour of optimum compacted composites to be better established. The inclusion of tyre shred substantially decreased the swelling potential/pressure and modestly lowered the compression index. Silt-Tyre powder replacement lowered the bulk density, allowing construction of lighter reinforced earth structures. The shear strength and stiffness decreased on addition of tyre powder, yet the contribution of matric suction to the shear strength remained constant for tyre shred contents up to 20%. Reinforced soils adopted a ductile post-peak plastic behaviour with enhanced failure strain, offering the opportunity to build more flexible subgrades as recommended for expansive soils. Residual water content and tyre shred content are directly correlated; tyre-reinforced silt showed a greater capacity of water storage (than natural silts) and hence a sustainable solution to waterlogging and surficial flooding particularly in urban settings. Crushed fine tyre shred mixed with expansive silts/sands at 15 to 20 wt% appear to offer the maximum reduction in swelling-shrinking properties at minimum cracking, strength loss and enhanced compressibility expenses.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.3
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• pp.264-272
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• 2019

The aim of this study is to analyze the relationship between international oil price as a fuel cost in overseas fisheries and skipjack tuna price as a part of main products in overseas fisheries using monthly time series data from 2008 to 2017. The study also tried to analyze the change of fishing profits by fuel cost. For a time series analysis, this study conducted both the unit-root test for stability of data and the Johansen cointegration test for long-term equilibrium relations among variables. In addition, it used not only the Granger causality test to examine interactions among variables, but also the Vector Auto Regressive (VAR) model to estimate statistical impacts among variables used in the model. Results of this study are as follows. First, each data on variables was not found to be stationary from the ADF unit-root test and long-term equilibrium relations among variables were not found from a Johansen cointegration test. Second, the Granger causality test showed that the international oil prices would directly cause changes in skipjack tuna prices. Third, the VAR model indicated that the posterior t-2 period change of international oil price would have an statistically significant effect on changes of skipjack tuna prices. Finally, fishing profits from skipjack would be decreased by 0.06% if the fuel cost increases by 1%.