• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.149-158
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• 2002

For the purpose of preciously describing real time traffic pattern in urban road network, dynamic network loading(DNL) models able to simulate traffic behavior are required. A number of different methods are available, including macroscopic, microscopic dynamic network models, as well as analytical model. Equivalency minimization problem and Variation inequality problem are the analytical models, which include explicit mathematical travel cost function for describing traffic behaviors on the network. While microscopic simulation models move vehicles according to behavioral car-following and cell-transmission. However, DNL models embedding such travel time function have some limitations ; analytical model has lacking of describing traffic characteristics such as relations between flow and speed, between speed and density Microscopic simulation models are the most detailed and realistic, but they are difficult to calibrate and may not be the most practical tools for large-scale networks. To cope with such problems, this paper develops a new DNL model appropriate for dynamic traffic assignment(DTA), The model is combined with vertical queue model representing vehicles as vertical queues at the end of links. In order to compare and to assess the model, we use a contrived example network. From the numerical results, we found that the DNL model presented in the paper were able to describe traffic characteristics with reasonable amount of computing time. The model also showed good relationship between travel time and traffic flow and expressed the feature of backward turn at near capacity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.548-555
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• 1994

To compare the tolerance of crops to acid rain at different growth stages a simulated acid rain (SAR) of pH 2.7 was applied to rice, soybean, and hot pepper from vegetative growth stage to harvest (Veget.-Harvest) and from reproductive growth stage to harvest (Reprod.-Harvest). Visual damages of crops by SAR were greater in the order of rice < hot pepper < soybean and greater at Veget.-Harvest than at Reprod.-Harvest treatment. Chlorophyll content of all crops was greater in the order of Veget.-Harvest < Reprod.-Harvest treatment < control, but photosynthetic activity was not affected by SAR treatments. Nitrogen concentration and uptake of rice plants at harvest were similar among SAR treatments, but those of soybean and hot pepper were greater at Veget.-Harvest treatment than at Reprod.-Harvest treatment or control. Sulfur concentration of all crops was not affected by SAR treatments, but total sulfur uptake of soybean was greater in SAR treatments than untreated control. Grain yield of rice and soybean was not affected by SAR although grain fertility, percent ripened grains, and 1,000-grain weight of rice at Veget.-Harvest treatment were lower compared with Reprod.-Harvest treatment or control. Fruit dry weight of hot pepper was greater in the order of Veget.-Harvest < Reprod.-Harvest < control due to decreased fruit number per plant and average fruit weight. At one time application of SAR at flowering stage, brown spots were observed on the spikelets of rice at below pH 2.3. Petals of soybean and hot pepper were wilted at pH below 1. 7 and 2.0, respectively, but fruit setting was not affected by the pH of the SRA.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.3
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• pp.199-212
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• 2007

If a type IP-2 transport package were to be subjected to a free drop test and a penetration test under the normal conditions of transport, it should prevent a loss or dispersal of the radioactive contents and a more than 20% increase in the maximum radiation level at any external surface of the package. In this paper, we suggested the analytic method to evaluate the structural safety of a type IP-2 transport package using a thick steel plate for a structure part and a bolt for tying a bolt. Using an analysis a loss or dispersal of the radioactive contents and a loss of shielding integrity were confirmed for two kinds of type IP-2 transport packages to transport radioactive waste drums from a waste facility to a temporary storage site in a nuclear power plant. Under the free drop condition the maximum average stress at the bolts and the maximum opening displacement of a lid were compared with the tensile stress of a bolt and the steps in a lid, which were made to avoid a streaming radiation in the shielding path, to evaluate a loss or dispersal of radioactive waste contents. Also a loss of shielding integrity was evaluated using the maximum decrease in a shielding thickness. To verify the impact dynamic analysis for free drop test condition and evaluate experimentally the safety of two kinds of type IP-2 transport packages, free drop tests were conducted with various drop directions. For the tests we examined the failure of bolts and the deformation of flange to evaluate a loss or dispersal of radioactive material and measured the shielding thickness using a ultrasonic thickness gauge to assess a loss of shielding integrity. The strains and accelerations acquired from tests were compared with those by analyses to verify the impact dynamic analysis. The analytic results were larger than the those of test so that the analysis showed the conservative results. Finally, we evaluated the safety of the type IP-2 transport package under the stacking test condition using a finite element analysis. Under the stacking test condition, the maximum Tresca stress of the shielding material was 1/3 of the yielding stress. Two kinds of a type IP-2 transport package were safe for the free drop test condition and the stacking test condition.

• Atmosphere
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• v.12 no.4
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• pp.20-42
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• 2002

Based on the "Mid to Long Term Plan for Space Development", a project to launch COMeS (Communication, Oceanography, and Meteorological Satellite) into the geostationary orbit is undergoing. Accordingly, KMA (Korea Meteorological Administration) has defined the meteorological missions and prepared the user requirements to fulfill the missions. To make a realistic user requirements, we prepared a first draft based on the ideal meteorological products derivable from a geostationary platform and sent the RFI (request for information) to the sensor manufacturers. Based on the responses to the RFI and other considerations, we revised the user requirement to be a realistic plan for the 2008 launch of the satellite. This manuscript introduces the revised user requirements briefly. The major mission defined in the revised user requirement is the augmentation of the detection and prediction ability of the severe weather phenomena, especially around the Korean Peninsula. The required payload is an enhanced Imager, which includes the major observation channels of the current geostationary sounder. To derive the required meteorological products from the Imager, at least 12 channels are required with the optimum of 16 channels. The minimum 12 channels are 6 wavelength bands used for current geostationary satellite, and additional channels in two visible bands, a near infrared band, two water vapor bands and one ozone absorption band. From these enhanced channel observation, we are going to derive and utilize the information of water vapor, stability index, wind field, and analysis of special weather phenomena such as the yellow sand event in addition to the standard derived products from the current geostationary Imager data. For a better temporal coverage, the Imager is required to acquire the full disk data within 15 minutes and to have the rapid scan mode for the limited area coverage. The required thresholds of spatial resolutions are 1 km and 2 km for visible and infrared channels, respectively, while the target resolutions are 0.5 km and 1 km.

• Journal of Labour Economics
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• v.24 no.3
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• pp.13-38
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• 2001

The question about whether a shorter workweek may increase employment has been a serious issue and been furiously debated among collective bargainers. The advocators recommend publicly that a reduction in standard working hours will provide benefits to the unemployed through the provision of new jobs, and also can improve the quality of life workers. The opponents argue that a shorter workweek will increase labor costs and induce firms to reduce their production levels, and consequently cut back their demand for labor. Although the debate is still continuing, considerable has been made toward achieving the goal workweek reduction. The analytical framework of this paper is a Putty-clay-model, in which the short-and long-term impacts of changes in working time on the employment associated with the interrelations of wages, prices, hourly labour productivity, the firm's labor demand, business cycle and economic growth etc. must be analyzed.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.417-428
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• 2005

Today, IT organizations perform projects with vision related to marketing and financial profit. The objective of realizing the vision is to improve the project performing ability in terms of QCD. Organizations have made a lot of efforts to achieve this objective through process improvement. Large companies such as IBM, Ford, and GE have made over $80\%$ of success through business process re-engineering using information technology instead of business improvement effect by computers. It is important to collect, analyze and manage the data on performed projects to achieve the objective, but quantitative measurement is difficult as software is invisible and the effect and efficiency caused by process change are not visibly identified. Therefore, it is not easy to extract the strategy of improvement. This paper measures and analyzes the project performance, focusing on organizations' external effectiveness and internal efficiency (Qualify, Delivery, Cycle time, and Waste). Based on the measured project performance scores, an OT (Opportunity Tree) model was designed for optimizing the project performance. The process of design is as follows. First, meta data are derived from projects and analyzed by quantitative GQM(Goal-Question-Metric) questionnaire. Then, the project performance model is designed with the data obtained from the quantitative GQM questionnaire and organization's performance score for each area is calculated. The value is revised by integrating the measured scores by area vision weights from all stakeholders (CEO, middle-class managers, developer, investor, and custom). Through this, routes for improvement are presented and an optimized improvement method is suggested. Existing methods to improve software process have been highly effective in division of processes' but somewhat unsatisfactory in structural function to develop and systemically manage strategies by applying the processes to Projects. The proposed OT model provides a solution to this problem. The OT model is useful to provide an optimal improvement method in line with organization's goals and can reduce risks which may occur in the course of improving process if it is applied with proposed methods. In addition, satisfaction about the improvement strategy can be improved by obtaining input about vision weight from all stakeholders through the qualitative questionnaire and by reflecting it to the calculation. The OT is also useful to optimize the expansion of market and financial performance by controlling the ability of Quality, Delivery, Cycle time, and Waste.

• Korean Security Journal
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• no.22
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• pp.37-64
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• 2010

Since the September 11, 2001, the motives and objectives of terrorism that have been targeted at hard targets such as key national facilities have now shifted towards soft targets such as subways, department stores, and tourist hotels; the attacks on these soft targets are steadily increasing. Simultaneous, unconventional, and indiscriminate terrorist attacks on civilians has also increased. In November, 2010, nearly forty states of the G20 and B20 (Business 20) will join in international summits to be hosted in Seoul. This coming July, an additional 350 troops will be deployed to Afghanistan for the sustainment of public security. Such events are sensitive topics, and there is the possibility of terrorist movement. Korea has successfully hosted various international events such as the APEC and ASEM Summits, and the 2002 Korea-Japan World Cup. The experiences from these events must be applied to ensure the safety of public facilities against the dangers of terrorism. First, counter-terrorism center must be established for the long-term, above the General Officer level to ensure the safety and efficiency of multilateral, international summits, as well as promoting policies and legislation aimed at preventing terrorism. Second, a terrorist threat management system must be secured and safety measures must be emphasized. Third, a fundamental structure must be established for the prevention of terrorism on public facilities, as well as legal and government action against the new threat of IED. Fourth, the police and fire fighting networks' must have a firm rapid response posture on the scene of an attack. Fifth, the state of mentality on the recognition of terrorist threats must be changed and restructured by promoting to and educating the population. Sixth, prevention measures must be established via research and academia. Seventh, for the guarantee of security in public facilities, safety management should employ cutting edge technology such as the 3D SICS and further develop and apply such technology. All methods and resources must be fully utilized for the establishment and strengthening terrorism prevention measures.

• Journal of Korea Water Resources Association
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• v.48 no.8
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• pp.613-623
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• 2015

To overcome the difficulties of discharge measurements during flood season, MWSCM(micowave water surface current meter) which measures river surface velocities without contacting water has been applied in field work since its development. The existing version of MWSCM is for floods so that its applicability is low due to the short periods of floods. Therefore the renovative redesign of MWSCM to increase the applicability was conducted so that it can be applied to the discharge measurements during normal flows as well as flood ones by extending the measurable range of velocity. A newly developed high-performance MWSCM for general use can measure the velocity range of 0.03-20.0 m/s from flood flows to normal flows, whereas MWSCM for floods can measure the velocity range of 0.5-10.0 m/s. The improvement of antenna isolation between transmitter and receiver to block the inflow of transmitted singals to receiver and the improvement of phase noise of oscillator are necessary for detecting low velocity with MWSCM technology. Separate type antenna of transmitting and receiving signals is developed for isolation enhancement and phase locked loop synthesizer as an oscillator is applied to high-performance MWSCM for general use. Microwave frequency of 24 GHz is applied to the new MWSCM rather than 10 GHz to make the new MWSCM small and light for convenient use of it at fields. Improvement requests on MWSCM for floods-stable velocity measurement, self test, low power consumtion, and waterproof and dampproof-from the users of it has been reflected on the development of the new version of MWSCM.

• Journal of The Korean Association For Science Education
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• v.31 no.2
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• pp.225-238
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• 2011

The purpose of this study was to investigate the effects of the instruction with question-creation training, compared with traditional science instructions. The instruction with question-creation training is to give students chances to make questions by themselves based on what they learned before the end of the classes. The four effects of the instruction were studied: students' achievement, metacognition, self-efficacy, and the level of the questions created by the students according to different proficiency levels. Research data was gathered from 65 second grade students at a middle school in Busan. The comparative group was instructed in traditional lecture-type teaching method. The experimental group was instructed with questioncreation training. Students in the experimental group were asked to make 3 questions by themselves and then, to solve their peers' questions about 15 minutes before the end of the classes. Both groups were divided into 3 groups by proficiency level according to the results of last semester's science test. Before the research, a metacognition test and a self-efficacy test were conducted. After the research, an achievement test, a question level test, a metacognition test, and a self-efficacy test were conducted and analyzed by t-test. The research data for question level was analyzed by one-way ANCOVA. The results of this study revealed that question-creation training has a positive effect on student's achievement, metacognition, and self-efficiency. It also showed most of the students have gained an ability to make higher-level questions regardless of their proficiency level due to the increased number of students who made higher-level questions. It also showed that most of the students could gain an ability to make higher-level questions regardless of their proficiency level from the fact that the number of students who made higher-level questions increased in every proficiency level.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.3
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• pp.1-16
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• 2012

Under the international business circumstance, global supply chain management is considered a vital strategic challenge to small and medium-sized enterprises(SMEs) suffering from deficient resources and capabilities to exploit overseas markets comparing with large corporations. That is because they can expand their business domains into overseas markets by establishing strategic alliances with global supply chain partners. Although a wide range of previous researches have emphasized the cooperative networks in the chain, most are ignoring the importance of developing relational characteristics such as trust and reciprocity with the partners. Besides, verifying the relational factors influencing firms' export performances, some studies proposed different and inconsistent factors. According to the social capital theory, which is the social quality and networks facilitating close cooperation of inter-individual and inter-organization, provides the integrated view to identify the relational characteristics in the aspects of network, trust and reciprocal norm. Meanwhile, a number of researchers shows that global entrepreneurship is the internal and intangible resource necessary to promote SMEs' internationalization. Upon closer examination, however, they cannot explain clearly its influencing mechanism in the inter-firm cooperative relationships. This study is to verify the effect of social capital accumulated within global supply chain on SMEs' qualitative and quantitative export performance. In addition, we shed new light on global entrepreneurship expected to be concerned with the formation of social capital and the enhancement of export performances. For this purpose, the questionnaires, developed through literature review, were collected from 192 Korean SMEs affiliated in Korean Medium Industries Association and Global Chief Executive Officer's Club focusing on their memberships' international business. As a result of multi-regression analysis, the social capital - network, trust and reciprocal norm shared with global supply chain partner - as well as global entrepreneurship - innovativeness, proactiveness and risk-taking - have positive effect on SMEs' export performances. Also global entrepreneurship affects positively social capital which has mediating effect partially in the relationship between global entrepreneurship and performances. These results means that there is a structural process - global entrepreneurship(input), social capital(output), and export performances(outcome). In other words, a firm should consistently invest in and develop the social capital with global supply chain partners in order to achieve common goals, establish strategic collaborations and obtain long-term export performances. Furthermore, it is required to foster the global entrepreneurship in an organization so as to build up the social capital. More detailed practical issues and discussion are made in the conclusion.