• Journal of The Korean Association For Science Education
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• v.26 no.4
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• pp.537-545
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• 2006

The purpose of this study was to analyze the effects of the SWH application to problem-solving type inquiry modules. The modules were applied to 23 3rd grade students in middle school located in Chungbuk and the SWH strategy was applied to 3 experimental groups. The blue and green cards were presented at the problem emerging situation to the students to give enough thinking time. Using blue cards students propose solution to the problem in advance individually, then they discuss with group members using green cards and conduct experiments to solve the problem. SWH students exhibited better problem recognition and attitude.

• Industrial Engineering and Management Systems
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• v.7 no.3
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• pp.257-265
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• 2008

This paper deals with the joint decisions on pricing and ordering for a monopolistic retailer who sells perishable goods with a fixed lifetime or demand period. The newsvendor-typed problem is formulated as a two-period inventory system where the first period represents the inventory of fresh or new-arrival items and the second period represents the inventory of items that are older but still usable. Demand may be for either fresh items or for somewhat older items that exhibit physical decay or deterioration. The retailer is allowed to adjust the selling price of the deteriorated items in the second period, which stimulates demand and reduces excess season-end or stale inventory. This paper develops a stochastic dynamic programming model that solves the problem of preseason decisions on ordering-pricing and a within-season decision on markdown pricing. We also develop a fixed-price model as a benchmark against the dual-price dynamic model. To illustrate the effect of the dual-price policy on expected profit, we conduct a comparative study between the two models. Extension to a generalized multi-period model is also discussed.

• Journal of the Korean Applied Science and Technology
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• v.26 no.2
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• pp.143-150
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• 2009

Today, wastes of much quantity by fast industrialization and increase in population, population concentration etc. of modem society are increasing. Much oyster shell is breeding by character and conduct of oyster-industry for a long time among them. Oyster shell which breed by-product in oyster cultivating industry that specific gravity of domestic seashore cultivating industry is high is causing environmental problem by problem and so on hindrance, nature spectacle's waste and health hygiene on administration if it is pollution of district along the coast fishing ground, number of public ownership being stored in open area in seashore. About new material just-in-time through recycling and he of oyster shell by these problem wide that study. Go forward more and investigate special quality that is oyster shell's physical chemistry red in this research and oyster shell oyster shell which cause several environmental problems developing ability agricultural chemicals that use this encapsulating micro by ability carrier that is environmentally application possibility examine wish to.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.331-341
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• 2011

This paper considers an inbound lot-sizing and outbound dispatching problem for a single product in a thirdparty logistics (3PL) distribution center. Demands are dynamic and finite over the discrete time horizon, and moreover, each demand has a delivery time window which is the time interval with the dates between the earliest and the latest delivery dates All the product amounts must be delivered to the customer in the time window. Ordered products are shipped by multiple vehicle types and the freight cost is proportional to the vehicle-types and the number of vehicles used. First, we formulate a mixed integer programming model. Since it is difficult to solve the model as the size of real problem being very large, we design a conventional genetic algorithm with a local search heuristic (HGA) and an improved genetic algorithm called adaptive genetic algorithm (AGA). AGA spontaneously adjusts crossover and mutation rate depending upon the status of current population. Finally, we conduct some computational experiments to evaluate the performance of AGA with HGA.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.159-165
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• 2014

For the hydrogen economy system being tried starting with the 21st century, the fields that was not dealt with so far, such as the safety measure for large leakage accidents, the safety problem at infrastructures like a hydrogen station, the safety problem in terms of automobiles depending on introduction of hydrogen cars, the safety problem in a supply for homes like fuel cells, etc., are being deeply reviewed. In order to establish a safety control system, an essential prerequisite in using and commercializing hydrogen gas as an efficient energy source, it is necessary to conduct an analysis, such as analysis of hydrogen accident examples, clarification of physical mechanisms, qualitative and quantitative evaluation of safety, development of accident interception technologies, etc. This study prepared scenarios of hydrogen gas leakage that can happen at hydrogen stations, and predicted damage when hydrogen leaks by using PHAST for this.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.167-168
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• 2018

The importance of business problem-solving creativity (BPSC) becomes crucial much more as competitive situations go on in the market. However, how to assess the BPSC remains an unsolved research issue yet in the literature. In this sense, this study proposes an exploratory analysis of the BPSC from the view of neuro-science experiments called fNIRS. The fNIRS represents a functional near-infrared spectroscopy, a new type of neuro-science research paradigm. This study proposes an exploratory level of how to conduct the fNIRS-based experiments to analyze the BPSC.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.541-552
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• 2018

The purpose of this study was to investigate the effects of 'problem posing from mathematical problems' on the students' affective domain of mathematics, and to conduct evaluation and management of teachers' respectively. The quantitative and qualitative approaches were combined to analyze the changes in the affective achievement of all the students and individual students in the study. The conclusions of this study are as follows: First, problem-posing class improved the problem-solving ability and meaningful experience in the learning activity itself, thus improving students' self-confidence, interest, value, and desire to learn. Second, The students' affective domain of mathematics should be emphasized, and systematic evaluation and management should be carried out from the first grade of middle school to high school senior in mathematics. Third, it is necessary to present and disseminate them in detail on the national-level to evaluation system and method of affective domain of mathematics. Therefore, the teacher should actively implement the problem-posing teaching and learning in the classroom lesson and help students' affective achievement. and teachers need to measure and manage the affective achievement of all students on a regular basis.

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.1
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• pp.93-114
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• 2018

The purpose of this study was to analyze mathematical the effects of problem posing activities on students' characteristics toward mathematics to encourage active learning. We will also examine various examples of the characteristics of the problems made by students with different mathematical characteristics. We chose one 6th grade group to conduct this research. From the results of this study, we obtained the following conclusions. First, problem posing activities are effective in improving students' mathematical interest and confidence, value recognition. Second, Students with different mathematical characteristics showed different results in problem posing activities. We confirmed the effectiveness of problem posing activities on students' positive characteristics of mathematics. In this regard, we were able to confirm examples of various problems that students made. In the future, we would like to propose generalization by conducting research on students of various school ages.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.4
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• pp.344-365
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• 2009

The performance of a tracking system is greatly increased if multiple types of sensors are combined to achieve the objective of the tracking instead of relying on single type of sensor. To conduct the multi-modal tracking, we have previously developed a multi-modal sensor-based tracking model where acoustic sensors mainly track the objects and visual sensors compensate the tracking errors [1]. In this paper, we find a network synchronization problem appearing in the developed tracking system. The problem is caused by the different location and traffic characteristics of multi-modal sensors and non-synchronized arrival of the captured sensor data at a processing server. To effectively deliver the sensor data, we propose a time-based packet aggregation algorithm where the acoustic sensor data are aggregated based on the sampling time and sent to the server. The delivered acoustic sensor data is then compensated by visual images to correct the tracking errors and such a compensation process improves the tracking accuracy in ideal case. However, in real situations, the tracking improvement from visual compensation can be severely degraded due to the aforementioned network synchronization problem, the impact of which is analyzed by simulations in this paper. To resolve the network synchronization problem, we differentiate the service level of sensor traffic based on Weight Round Robin (WRR) scheduling at the routers. The weighting factor allocated to each queue is calculated by a proposed Delay-based Weight Allocation (DWA) algorithm. From the simulations, we show the traffic differentiation model can mitigate the non-synchronization of sensor data. Finally, we analyze expected traffic behaviors of the tracking system in terms of acoustic sampling interval and visual image size.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1142-1147
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• 2015

As a method to increase the scalability and efficiency of wireless sensor networks, a scheme to construct networks hierarchically has received considerable attention among researchers. Researches on the methods to construct wireless networks hierarchically have been conducted focusing on how to select nodes such that they constitute a backbone network of wireless network. Nodes comprising the backbone network should be connected themselves and can cover other remaining nodes. A problem to find the minimum number of nodes which satisfy these conditions is known as the minimum connected dominating set (MCDS) problem. The MCDS problem is NP-hard, therefore there is no efficient algorithm which guarantee the optimal solutions for this problem at present. In this paper, we propose a novel multi-start local search algorithm to solve the MCDS problem efficiently. For the performance evaluation of the proposed method, we conduct extensive experiments and report the results.