• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.89-93
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• 2014

Variable polarity (VP) arc welding is known as an effective solution for aluminum thanks to the cleaning effect, which means oxide removal, during the DCEP (direct current electrode positive) period. In this research, VP GTAW (gas tungsten arc welding) is adopted for lap joint fillet welding of 3mm thickness 5052 aluminum alloy. Various welding currents and DCEP duty cycles are applied as welding conditions with a fixed welding speed to investigate the influence of DCEP characteristics on weld bead formation. Results show a tendency of higher heat input for higher DCEP duty cycle, which result does not follow conventional arc theory because it is known that DCEN (DC electrode negative) polarity is more efficient for heat input than is DCEP. This phenomenonhas recently been reported by several VP-GTA researchers and is still controversial because the mechanism of oxide removal is not yet clear except for the previous, well-known idea of "ion bombardment", which cannot explain the situation. Finally, proper usage conditions for VP-GTAW are suggested; then, further, related theoretical topics in the field of cathode physics are brieflyintroduced.

• Proceedings of the Technology Innovation Conference
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• 1998.06a
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• pp.226-249
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• 1998

Technology diffusion policy can be defined as the role of government in linking knowledge production with usage. It has an importance due to the fact that linking knowledge between the producing agent and using agent does not automatically occur. If knowledge produced by an R&D agent is not used by somebody else, the knowledge may deteriorate to a social loss since knowledge production consumes a considerable degree of social resources. Explicit technology diffusion policies are not found in Korea. There we, however, a number of implicit policies to promote technology diffusion, mainly by promoting cooperation among universities, industries and research institutes. Government R&D programs have provided incentives for cooperative research projects, and many government sponsored institutes have been assigned the role of technology assistance for small and medium sized firms. Nevertheless, diffusion policies remain weak in comparison to other innovation and technology policies. This is reflected in the relatively small scale of government support for technology diffusion programs. In addition, there is no systematic approach between the different ministries for enhancing diffusion across technologies, institutions, sectors and regions. A comprehensive evaluation of government diffusion programs, which is necessary for improving policy and program design, is lacking. Enhancing the diffusion of technology in Korea will require the strengthening of policies at different levels, including; 1) increasing the orientation of science and technology policies towards diffusion; 2) increasing the scale of existing diffusion programs; 3) developing new diffusion programs, in particular sector-specific or manpower training programs; 4) developing policies to encourage a culture of cooperation that can facilitate technology diffusion; and 5) carrying out substantial policy research to develop diffusion policies.

• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.172-180
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• 2013

We herein consider a stochastic multi-item inventory management problem in which a warehouse sells multiple items with stochastic demand and periodic replenishment from a supplier. Inventory management requires the timing and amounts of orders to be determined. For inventory replenishment, trucks of finite capacity are available. Most inventory management models consider either a single item or assume that multiple items are ordered independently, and whether there is sufficient space in trucks. The order cost is commonly calculated based on the number of carriers and the usage fees of carriers. In this situation, we can reduce future shipments by supplementing items to an order, even if the item is not scheduled to be ordered. On the other hand, we can reduce the average number of items in storage by reducing the order volume and at the risk of running out of stock. The primary variables of interest in the present research are the average number of items in storage, the stock-out volume, and the number of carriers used. We formulate this problem as a multi-objective optimization problem. In a numerical experiment based on actual shipment data, we consider the item shipping characteristics and simulate the warehouse replenishing items coordinately. The results of the simulation indicate that applying a conventional ordering policy individually will not provide effective inventory management.

• Journal of Korea Multimedia Society
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• v.23 no.4
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• pp.574-580
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• 2020

Stress induces change to the body functions and causes chronic problems such as worsening a disease. Thus, humans want to evade anxiety and would try any means to reduce stressful situations. Generally, a person would handle their stress by either regulating their emotions or merely coping with the situation, for which the former is most widely used. Our research aims to effectively reduce stress by using the emotional response structure developed by Plutichik and the vitalization method. We extracted the relevant components of the stress-reduction method that would be applicable in any space using digital technologies such as sensors, IoT, and augmented reality. An architect or designer may incorporate these structural components into any structure to effectively reduce people's stress. The research aims to provide a new perspective of architectural space and to show applications of the stress-reducing architectural spaces, which should also fulfill the people's needs. Further research is needed to develop an automatic system to utilize spatial components more effectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.92-97
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• 2012

In the present the usage of bicycle has increased steeply due to well-being and convenient way of movement. In car to bicycle accident, the throw distance of bicycle is very important factor for estimating collision situation. In this study, simulations and collision tests in actual car to bicycle were executed for obtaining throw distance of bicycle. The simulations were executed by PC-CRASHTM s/w with vehicle of sedan type. Sand bags were used for the behavior of bicyclist instead of dummy and factors considered were vehicle velocity, the crashed angles and part of bicycle to vehicle, and bicycle was adult type. From the results, the throw distances of tire collision of 00 was longer than that of 450 tire crash, and the throw distances of 900 frame crash were longer than those of 450 frame crash. With based on actual crash tests and simulations, restitution coefficient of between vehicle and bicycle was estimated as 0.1. Finally the increaser vehicle velocity the longer the throw distances of bicycle and the simulation results were relatively good agreement to the results of experiment.

• Journal of Information Technology Services
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• v.15 no.1
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• pp.245-253
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• 2016

Background in a novel is most important elements with characters and events, and means time, place and situation that characters appeared. Among the background, spatial background can help conveys topic of a novel. So, it may be helpful for choosing a novel that readers want to read. In this paper, we are targeting Korean historical novels. In case of English text, It can be recognize spatial background easily because it use upper and lower case and words used with the spatial information such as Bank, University and City. But, in case Korean text, it is difficult to recognize that spatial background because there is few information about usage of letter. In the previous studies, they use machine learning or dictionaries and rules to recognize about spatial information in text such as news and text messages. In this paper, we build a nation dictionaries that refer to information such as 'Korean history' and 'Google maps.' We Also propose a method for recognizing spatial background based on patterns of postposition in Korean sentences comparing to previous works. We are grasp using of postposition with spatial background because Korean characteristics. And we propose a method based on result of morpheme analyze and frequency in a novel text for raising accuracy about recognizing spatial background. The recognized spatial background can help readers to grasp the atmosphere of a novel and to understand the events and atmosphere through recognition of the spatial background of the scene that characters appeared.

• Education of Primary School Mathematics
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• v.7 no.2
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• pp.85-99
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• 2003

In this paper, firstly examined various proofs types that cover informal empirical justifications by Balacheff, Miyazaki, and Harel ＆ Sowder and Tall. Using these theoretical frameworks, justification activities by 5th graders were analyzed and several conclusions were drawn as follow: 1) Children in 5th grade could justify using various proofs types and method ranged from external proofs schemes by Harel & Sowder to thought experiment by Balacheff This implies that children in elementary school can justify various mathematical statements of ideas for themselves. To improve children's proving abilities, rich experience for justifying should be provided. 2) Activities that make conjectures from cases then justify should be given to students in order to develop a sense of necessity of formal proof. 3) Children have to understand the meaning and usage of mathematical symbol to advance to formal deductive proofs. 4) New theoretical framework is needed to be established to provide a framework for research on elementary school children's justification activities. Research on proof mainly focused on the type of proof in terms of reasoning and activities involved. But proof types are also influenced by the tasks given. In elementary school, tasks that require physical activities or examples are provided. To develop students'various proof types, tasks that require various justification methods should be provided. 5) Children's justification type were influenced not only by development level but also by the concept they had. 6) Justification activities provide useful situation that assess students'mathematical understanding. 7) Teachers understanding toward role of proof(verification, explanation, communication, discovery, systematization) should be the starting point of proof activities.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.268-274
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• 2007

The present paper investigates a particular structure in Taiwan Mandarin, "(NP) + (intensifier) + $gei^3ta^1$ "give him/it"+ adjective" in terms of construction grammar. The structure is mostly observed in utterances of younger generation. Though it is not regarded as a grammatical or standard structure, it is still a register of language. The structure lays emphasis on speaker's attitude toward an undesired, unpleasant event. In most cases, the attitude tends to be negative. The events or propositions must have existed or been completed. The adjectives compatible with this structure belong to category of higher degree. The grammatical usage illustrates semantic bleaching of $gei^3ta^1$. And the changes from giving to a grammatical particle denoting subjective belief is a kind of subjectification. Moreover, $ta^1$ could refer to events or situation expressed by a more complicated grammatical structure, or denotes nothing as a dummy word. Though many previous studies paid attention to the newly developed structure resulted from language contact, the adequate account was not provided. It is hoped through this investigation, we will get a better understanding of this particular structure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.5
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• pp.1554-1566
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• 2014

Cloud Computing allows application providers seamlessly scaling their services and enables users scaling their usage according to their needs. In this paper, using queuing game model, we present service scheduling schemes which are used in software as a service (SaaS). The object is maximizing the Cloud Computing platform's (CCP's) payoff via controlling the service requests whether to join or balk, and controlling the value of CCP's admission fee. Firstly, we treat the CCP as one virtual machine (VM) and analyze the optimal queue length with a fixed admission fee distribution. If the position number of a new service request is bigger than the optimal queue length, it balks. Otherwise, it joins in. Under this scheme, the CCP's payoff can be maximized. Secondly, we extend this achievement to the multiple VMs situation. A big difference between single VM and multiple VMs is that the latter one needs to decide which VM the service requests turn to for service. We use a corresponding algorithm solve it. Simulation results demonstrate the good performance of our schemes.

• KIEAE Journal
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• v.16 no.2
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• pp.23-31
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• 2016

Purpose: Recently energy consumption is rapidly increasing due to continuous development of social evolution in various field. In this situation, there is a lot of effort to reduce this energy consumption in many ways, especially in building energy. Preceding studies already started to analyze the housing area such as zero energy house and passive house by researching annual building energy consumption, but to apply the results of housing to office building is insufficient since it has different consumption tendency. Method: In this study, eQuest program was used for simulation and the base model is selected among standard office building in ASHRAE 90.1. Variables are divided into passive and active factors for comparison. Result: In passive factors, glazing system showed the highest energy saving rate by 21.3% with triple low-e glass and enhancing wall u-value showed the lowest energy saving rate by 3.6% with 0.15 m2/K. In active factors, VAV system showed 30.9% energy saving rate when compared to CAV system, and heat exchanger showed 10.2% energy saving rate. For regeneration energy part, photovoltaic panel generated 10.4% of base annual energy usage.