• Nuclear Engineering and Technology
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• v.25 no.3
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• pp.361-370
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• 1993

Low power physics tests should be peformed for the domestic pressurized light water reactors (PWRs) after refueling. The tests are peformed to ensure that operating characteristics of the core are consistent with predictions and that the core can be operated as designed. But in some low power physics tests, slow but steady reactivity increasing phenomena were noticed after step reactivity insertion by the control rod movement. These reactivity increasing phenomena are due to the low flux level and the gamma background because an uncompensated ion chamber (UIC) is used as the ex-core neutron detector. The gamma background may affect the results or the lour power physics tests. The aims or this paper are to analyze the grounds of such phenomena, to simulate a reference bank worth measurement test and to present a resolution quantitatively. In this study, the gamma background level was estimated by numerically solving the point kinetics equations accounting the gamma background effect. The reactivity computer check test was simulated to verify the model. Also, an appropriate neutron flux level was determined by simulating the reference bank worth measurement test. The determined neutron flux level is approximately 0.3 of the nuclear heating flux. This level is about 3 times as high as the current test upper limit specified in the test procedure. Then, the findings from this work were successfully applied to Kori unit 4 cycle 7 and Yonggwang unit 1 cycle 7 physics tests.

• Korean Journal of Construction Engineering and Management
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• v.23 no.4
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• pp.26-35
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• 2022

The 7th education reform in 1997 has led changes in the way buildings were constructed and such changes drove educational facilities to steadily consume more energy every year. Also, these facilities take several years' estimated expenditure as well as the increased unit price of electricity into account when planning their annual operating budget. Such circumstances may adversely affect the establishment of their budget plan since improper allocation of operating costs could take place. To propose educational facilities' operating budget management plan on electrical energy consumption, this study developed a model that help oversee the facilities' consumption of electrical energy. For the model development, the primary core variables related to electrical energy factors from the aspects of surroundings, physics, policy, etc. were derived from taking both literature research and the characteristics of these facilities into account. The secondary core variables were then derived using the correlation analysis. Lastly, the electric energy use prediction model was developed by performing regression analysis based on the derived secondary core variables.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.172-187
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• 2022

In the era of 'Experience Economy' user experience has emerged as a core value of a product, affecting the sustainability of the product and the long-term market viability. However, studies on product user experience factors (PUX factors) that affect the sustainability of the product still limited. Therefore, the purpose of this study is to investigate the relationship between the PUX factors and the continuance usage intention with wireless earphones, which is a wearable product that is widely used to enjoy music in everyday life. The study uses three types of wireless earphones as the target product to insight into the differentiation of this relationship represents in different types of product. The research process consisted of four steps: 1) "Investigation on the current status of wireless earphones market", 2) "User survey and derivation of PUX factors", 3 "Analyzing the relationship between PUX factors and continuance usage intention", 4) "Output of analysis results and direction of product experience design". Through this research process, it was found that the core PUX factors that influence product sustainability were different depending on the type of wireless earphone. According to the differentiation of the core PUX factors, a variety of design methods for improving product experience and product sustainability was presented.

• Journal of Arbitration Studies
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• v.30 no.2
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• pp.145-164
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• 2020

With the development of the Internet, e-commerce is rapidly developing, and e-commerce through the Internet has become a major distribution channel for selling products and services to consumers and buyers. However, as Internet shopping develops, consumer dissatisfaction and conflict are increasing. In this regard, this study examined how consumer dissatisfaction caused by using an Internet shopping mall, which is currently taking the core position in commerce activities, leads to consumer complaints, and how these complaints affect the necessity and intention to use the arbitration system. As a result of the study, the following implications were obtained. First, it will be necessary to remove the root cause of consumer complaints by continuously monitoring consumer complaints, rather than staying at passive consumer complaints such as defective product exchange and damage compensation for dissatisfaction with Internet shopping malls. Second, it can be said that the function of the arbitration system is required to protect the rights and interests of consumers using the Internet shopping mall and to actively improve the problems in the event of a damage situation or a problem situation. Lastly, academia's continuous research will be needed, and governments and related organizations will need to continuously provide and promote information to users of Internet shopping malls.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.185-192
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• 2002

The performance of old and the new concrete construction depends upon bond strength between old and the new concrete. Current adhesive and strength measurement method ignores the effect of stress concentration from shape of specimens. Therefore, this research calculates stress concentration coefficient as the ratio of drilling depth to drilling diameter($h_s/D$), the ratio of overlay thickness to drilling diameter($h_0/D$), the ratio of steel disk thickness to drilling diameter(t/D), the ratio of overlay elastic modulus to substrate modulus($E_1/E_0$), the distance from core to corner border(L_$_{corner}$) and the distance between cores(L_$_{coic}$) vary. The finite element method is adapted to analysis The results from 'the F.E.M analysis are as follows. The stress concentration effects can be minimized when the ratio of drilling depth to drilling diameter($h_s/D$) is 0.20~0.25, the elastic modulus ratio($E_1/E_0$) is 06~1.0, and the ratio of steel disk thickness to drilling diameter(t/D) is 3.0. The overlay thickness, the distance from specimens to corner border(L_$_{corner}$), the distance between cores(L_$_{coic}$) almost do not affect to the stress concentration.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.485-490
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• 2002

Demands of customers are being changed and varied. And in this circumstance, it become a main issue of management that the company should produce and sell products according to the customer demands. With these trends, each company has been concentrating effects on generalization of product development technique and distinction of service for customer. To fulfill these demands of customer, they need a concept of eCRM(Web based Customer Relationship Management), and go from soiling products and services, or gathering customer requests, up to the phase of solving customer's problem by real time or previous action. With the help of internet, the frequency and speed of the problem solving has improved greatly. In the Supply chain, The ATP(Available to Promise) function doesn't only give customers to conformation of delivery. It can be used by the core function with ATP rule that can reconcile supplies and demands on the supply chain. Therefore We can be acquire the conformation about on the due date of supplier by using the ATP function of management about real and concurrent access on the supply chain, also decide the affect about product availability due to forecasting or customer's orders through the ATP. In this paper, It consolidates the necessity on a ATP and analyzes data which is concerned of ATP. Under the these environments, defines the ATP rule that can improve the customer value and data flow related the eCRM and builds on a algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2355-2363
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• 2002

The accompanying paper, Part 1, has presented the physical modeling and basic numerical analysis results of both the flow-induced and thermally-induced residual stress and birefringence in injection molded center gated disks. The present paper, Part II, has attempted to investigate the effects of various processing conditions of injection/compression molding process on the residual stress and birefringence. The birefringence is significantly affected by injection melt temperature, packing pressure and packing time. Birefringence in the shell layer increases as melt temperature gets lower. The inner peak of birefringence increases with packing time and packing pressure. On the other hand, packing pressure, packing time and mold wall temperature affect the thermally-induced residual stress rather significantly in the shell layer, but insignificantly in the core region. Injection/compression molding has been found to reduce the birefringence in comparison with the conventional injection molding process. In particular, mold closing velocity and initial opening thickness in the compression stage of injection/compression molding process have significant effect on the flow-induced birefringence, but not on tile thermal residual stress and the thermally induced birefringence.

• Journal of Internet Computing and Services
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• v.17 no.4
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• pp.161-172
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• 2016

The following research investigates core factors required for IT professionals to achieve and remain happy on their jobs through dynamic and structural CLD and suggests personal, organizational, and government level (happiness) promoting factors. Researcher adopted the system dynamics methodology which is qualitative research techniques pursue behavior probability by using CLD. It spotlights 6 CLD: job satisfaction, organizational commitment, positive sensitivity, negative sensitivity, amicable relationship, job sustainment intention, in addition to numerous factors that affect them from an integrative perspective. It differentiates itself from one-way relationship focused qualitative research to an advanced mutual and realistic perspective exploratory research.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.3
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• pp.54-60
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• 2001

A newly designed inductive micro displacement detecting system is presented. The proposed inductive system consists of driving coils, position-detecting coils, cores, and closed-loop formed magnetic blocks. The cores and magnetic blocks are made of Mn-Zn ferrite. When AC sine wave is applied to the driving coils, the time derivative flux is generated within the system, and then induced voltages arise in the position-detecting coils according to the core\`s position. Putting the cores to be moved proportionally to the input displacement, the induced voltage is proportional to input displacement. The parameters that affect the system characteristics are turn ratio, air-gap size, excitation frequency, overlap area, load resistance, capacitance effect, and so forth. Based on the experimental results, the system parameters are selected in such a way as to have high sensitivity ad stable responses. The sensitivity of the proposed inductive displacement-detecting system is greater than 2800mV.V-1mm-1 and the linearity error is below $\pm$0.10% in the range of $\pm$200㎛.

• Journal of the Korean Ceramic Society
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• v.48 no.4
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• pp.293-297
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• 2011

The thermodynamic behavior of phenolic resin was investigated to verify the relation between the properties of porous ceramics with $ZrO_2$-C system for submerged entry nozzle and the characteristics of phenolic resin with various relative humidity. The green and the sintered density were decreased between 25% and 50% relative humidity, whereas they were gradually enhanced above 50% relative humidity. The highest value of apparent porosity was 20.1% and the minimum compressive strength was 69MPa in the specimen using the powder exposed to 50% relative humidity. As a result of thermal analysis for phenolic resin, the shift of endothermic peak to low temperature and the reduction of exothermic peak were observed, and the peaks corresponded to melting and curing of phenolic resin, respectively. The melting and the curing of phenolic resin generate the change of green density, and it can affect the properties of submerged entry nozzle.