• Hwankyungkyoyuk
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• v.19 no.2 s.30
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• pp.133-146
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• 2006

The purpose of this study was to examine how environmental education teachers think about environmental teaching materials of their use in primary and secondary schools. For this purpose, six primary and secondary school teachers were selected for focus group discussion on October 17th, 2005. The discussion of focus group was recorded both on video and audio tapes. Teachers' discussion could be analyzed in the perspectives of two big ideas, 'content selection' and 'content organization and presentation'. The big ideas were categorized into several areas: 1) The idea of 'content selection' was classified into 4 areas such as integration, difficulty level, locality, and timeliness, 2) The idea of 'content organization and presentation' was classified into 4 areas such as learning motivation, teaching and teaming strategy, evaluation method, application of teaching materials. This study provided meaningful ideas, which can be used in developing environmental education materials as well as effective teaching and teaming strategies for school environmental educators.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3542-3566
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• 2018

In this paper, we investigate a buffer-aided wireless powered cooperative communication network (WPCCN), in which the source and relay harvest the energy from a dedicated power beacon via wireless energy transfer, then the source transmits the data to the destination through the relay. Both the source and relay are equipped with an energy buffer to store the harvested energy in the energy transfer stage. In addition, the relay is equipped with a data buffer and can temporarily store the received information. Considering the buffer-aided WPCCN, we propose two buffer-aided relaying protocols, which named as the buffer-aided harvest-then-transmit (HtT) protocol and the buffer-aided joint mode selection and power allocation (JMSPA) protocol, respectively. For the buffer-aided HtT protocol, the time-averaged achievable rate is obtained in closed form. For the buffer-aided JMSPA protocol, the optimal adaptive mode selection scheme and power allocation scheme, which jointly maximize the time-averaged throughput of system, are obtained by employing the Lyapunov optimization theory. Furthermore, we drive the theoretical bounds on the time-averaged achievable rate and time-averaged delay, then present the throughput-delay tradeoff achieved by the joint JMSPA protocol. Simulation results validate the throughput performance gain of the proposed buffer-aided relaying protocols and verify the theoretical analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1257-1265
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• 2015

In this paper, we describe a greedy user selection scheme for multiuser multiple-input multiple-output (MIMO) systems. We propose a new metric which has significantly improved performance compared to the Frobenius norm metric. The approximation of projection matrix is applied to increase the accuracy of Frobenius norm of effective channel matrix. We analyze the computational complexity of two metrics by using flop counts, and also verify the achievable sum rate through numerical simulation. Our simulation result shows that the proposed metric can achieve the improved sum rate as the number of user antenna increases.

• Journal of the Korean Solar Energy Society
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• v.25 no.2
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• pp.63-69
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• 2005

This study is the survey of a transition procedure of building services systems(heat source, HVAC, water supply) through the survey of existing office buildings, building design documents. The preference & major consideration of system selection is the engineer's opinions. The results of this survey can be used in selection of building services system design. In this survey, "Hot & cold water generator system" and "single duct CAV+FCU system", "Elevated water tank system" are selected. The most important consideration in system selection is the energy saving in heat source system, and comfort in HVAC system, and water pressure in water supply system. They prefer "steam boiler+absorption chiller system" for heat source system, "steam boiler+ice thermal storage system", "hot & cold water generator system", "district heating+absorption chiller system" : "single duct CAV+FCU system" and "single duct VAV+convector system" for HVAC system: and "booster pump system" for water supply system.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.443-454
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• 2014

In this paper, an intuitive emotional expression of the 3D avatar is presented. Using the motion selection control of 3D avatar, an easy-to-use communication which is more intuitive than emoticon is possible. 12 pieces different emotions of avatar are classified as positive emotions such as cheers, impressive, joy, welcoming, fun, pleasure and negative emotions of anger, jealousy, wrath, frustration, sadness, loneliness. The combination of lower body motion is used to represent additional emotions of amusing, joyous, surprise, enthusiasm, glad, excite, sulk, discomfort, irritation, embarrassment, anxiety, sorrow. In order to get the realistic human posture, BVH format of motion capture data are used and the synthesis of BVH file data are implemented by applying the proposed emotional expression rules of the 3D avatar.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.485-493
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• 2006

Lactococcus species are noninvasive and nonpathogenic microorganisms that are widely used in industrial food fermentation and as well-known probiotics. They have been modified by traditional methods and genetic engineering to produce useful food-grade materials. The application of genetically modified lactococci in the food industry requires their genetic elements to be safe and stable from integration with endogenous food microorganisms. In addition, selection for antibiotic-resistance genes should be avoided. Several expression and secretion signals have been developed for the production and secretion of useful proteins in lactococci. Food-grade systems composed of genetic elements from lactic acid bacteria have been developed. Recent developments in this area have focused on food-grade selection markers, stabilization, and integration strategies, as well as approaches for controlled gene expression and secretion of foreign proteins. This paper reviews the expression and secretion signals available in lactococci and the development of food-grade markers, food-grade cloning vectors, and integrative food-grade systems.

• Smart Structures and Systems
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• v.2 no.2
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• pp.189-208
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• 2006

Monitoring large-scale civil engineering structures such as offshore platforms and high-large buildings requires a large number of sensors of different types. Innovative sensor data information technologies are very extremely important for data transmission, storage and retrieval of large volume sensor data generated from large sensor networks. How to obtain the optimal sensor set and placement is more and more concerned by researchers in vibration-based SHM. In this paper, a method of determining the sensor location which aims to extract the dynamic parameter effectively is presented. The method selects the number and place of sensor being installed on or in structure by through the tolerance domain statistical inference algorithm combined with second order sensitivity technology. The method proposal first finds and determines the sub-set sensors from the theoretic measure point derived from analytical model by the statistical tolerance domain procedure under the principle of modal effective independence. The second step is to judge whether the sorted out measured point set has sensitive to the dynamic change of structure by utilizing second order characteristic value sensitivity analysis. A 76-high-building benchmark mode and an offshore platform structure sensor optimal selection are demonstrated and result shows that the method is available and feasible.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.430-438
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• 2021

The spatial distribution of neutron flux or reaction rate was calculated by cell or mesh tally in traditional Monte Carlo simulation. However, either cell or mesh tally leads to the increase of memory consumption and simulation time. In this paper, the function expansion tally (FET) method was developed in Reactor Monte Carlo code RMC to solve this problem. The FET method was applied to the tallies of neutron flux distributions of uranium block and PWR fuel rod models. Legendre polynomials were used in the axial direction, while Zernike polynomials were used in the radial direction. The results of flux, calculation time and memory consumption of different expansion orders were investigated, and compared with the mesh tally. Results showed that the continuous distribution of flux can be obtained by FET method. The flux distributions were consistent with that of mesh tally, while the memory consumption and simulation time can be effectively reduced. Finally, the convergence analysis of coefficients of polynomials were performed, and the selection strategy of FET order was proposed based on the statistics uncertainty of the coefficients. The proposed method can help to determine the order of FET, which was meaningful for the efficiency and accuracy of FET method.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.9
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• pp.351-360
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• 2022

This study aims to determine the factors that can influence investors in selecting stocks in the Indonesian capital market to establish an optimal portfolio, and find phenomena that occurred during the COVID-19 pandemic so that buying interest / the number of investors increased in the Indonesian capital market. This study collection technique uses primary data obtained from the survey questionnaire and secondary data which is market data, stock price movement data sourced from the Indonesia Stock Exchange, Indonesian Central Securities Depository, and Bank Indonesia, as well as empirical literature on behavior finance, investment decision, and interest in buying stock. The method used in this research is the survey questionnaire analysis with the SEM (statistical approach). The results of the analysis using SEM show that investor behavior influences the stock-buying interest, investor behavior, and the stock-buying interest influences investor decision-making. However, risk management does not influence investor-decision making. This occurs when the investigator's psychological capacity produces more decision information by decreasing all potential biases, allowing the best stock selection model to be selected. When the investigator's psychological capacity creates more decision information by reducing biases, the optimum stock selection model can be chosen.

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.226-239
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• 2007

The purpose of this study was to identify the problems related to the purchasing processes of school foodservices that should be corrected for the food service safety, by examining the purchasing processes and the status of supplier selection. A questionnaire was given to 300 dietitians working at self-operated food services. Ninety-eight responses, excluding incomplete answers, were used for the statistical analysis. The survey consisted of three parts: the general characteristics of the school foodservice and dietitian, purchasing processes and supplier selection, and the purchase specifications. We found that 84% of the contract was made by informal purchasing, and the contract period was 6 months or one year. For supplier selection, problems related to the document screening systems were the superficiality of the content(45.7%) and the absence or lack of clarity of the appraisal criteria(34.8%). The important factors for the facility and equipment standards of suppliers were included unclear evaluation methods for content(41.1%) and inappropriate appraisal lists(21.1%), while unclear evaluation methods for content(41.9%) and absence or lack of clarity of the appraisal criteria(20.4%) were the problems pertaining to the supplier evaluation checklist. When using the Food Labeling Standards to select suppliers, confirmation of the sell-by date and the storage method had the highest score at 3.85 out of 5. For supplier selection, only 25% of the contract was made by using the purchase specifications. The levels of satisfaction of with Kimchi and rice cakes suppliers were significantly different according to employment type and educational background, respectively. Depending on working experiences, satisfaction was significantly different for the use of document screening, as a standard for the selection and management of suppliers, and for the facility and equipment standards of suppliers, The use of purchase specifications was different by employment type, while the use of purchase specifications for contracts was different by working experience. These results imply that the specialization of suppliers is necessary to unsure food safety. Therefore, the objective methods to evaluate the suppliers should be developed by the government, and appropriate education programs for dietitians should be prepared to enhance the utilization of purchase specifications.