• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.4
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• pp.159-166
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• 2018

The Korean fenestration energy consumption efficiency rating system only considers thermal performance of the heat transfer coefficient (U-value) and airtightness excluding optical characteristics of the solar heat gain coefficient (SHGC). This study analyzed annual heating and cooling energy requirements on the middle floor of apartment by optical and thermal performance of windows to evaluate the suitability of the rating system. One hundred and twenty-eight windows were analyzed using THERM and WINDOW 7.4, and energy simulation for a reference model of an apartment house facing south was performed using TRNSYS 17. The results showed that window performance was the main factor in the heating and cooling load. The heating load of the reference model was 539 kWh to 2,022 kW, and the cooling load was 376 kWh to 1,443 kWh. The coefficient of determination ($R^2$) of the heating and cooling loads driven from the SHGC were 0.7437 and 0.9869, which are more compatible than those from the U-value, 0.0558 and 0.4781. Therefore, it is not reasonable to evaluate the energy performance of windows using only the U-value, and the Korean fenestration energy consumption efficiency rating system requires a new evaluation standard, including SHGC.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.217-225
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• 2014

The objective of this study is to propose the implications using theory of reasoned action(TRA) on u-Tour system. This research model through TRA is consisted as three constructs: user-friendliness(cognitive), perceived usefulness(cognitive) and purchase intention(affective). This study analyzes with a total of 153 respondents and used PLS-SEM method considering the small number of samples. Also, with the analysis, WarpPLS software is used in order to ferret out non-linear relationship between the constructs of research model. As a result of analysis, this research model shows statistical level significantly on proposed hypotheses and the applicability of TRA model in u-Tour system. Furthermore, additional analysis presents the possibility of non-linear relationship on each path between the constructs of research model showing J-shape. Also, the result showes the fact that the relationship had partly negative (-) effect on dependent factor. Additional analysis proposes that income variable as base of purchase intention has a moderating effect on all paths of research model.

• Journal of agricultural medicine and community health
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• v.19 no.2
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• pp.107-118
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• 1994

Health effects of pesticide among vinylhouse workers in Sangjoo County, Kyungpook Province were assessed by measuring cholinesterase, glutathion reductase, and methemoglobin. Activities of cholinesterases among vinylhouse workers and general farmers were 3.89U and 3.98U in serum and 5.29U and 5.50U in red blood cells, respectively. While levels of methemoglobin between vinylhouse workers(0.16%) and general farmers(0.17%) were very similar, glutathione reductase among vinylhouse workers were 8% lower than that of general farmers. Inhibition of RBC cholinesterase among vinylhouse workers was two times greater than general farmers, suggesting a greater exposure of vinylhouse workers to the organophosphate pesticides. Methemoglobin level among vinylhouse workers with more than or equal to 10 vinylhouse units was 13% higher than that of the workers with less than 10 units. Vinylhouse workers using protective gears during pesticide spray showed higher level of reduced glutathione and lower level of methemoglobin, as compared to the non-users. This indicates that protective gears play an important role against pesticide exposure. Vinylhouse workers practicing good personal hygiene showed a higher level of reduced glutathione, as compared to those with poor personal hygiene, indicating that personal hygiene is also an important factor in reducing pesticide exposure. The present study represents a first attempt to analyze cholinesterase, methemoglobin and glutathione reductase activities among the vinylhouse workers. While neither vinylhouse workers nor general farmers showed abnormal findings among biochemical parameters used in the present study, increased level of methemoglobin and decrease of glutathione reductase activity among vinylhouse workers suggest that these workers have been subject to a higher exposure of pesticide than general farmers.

• Journal of the Korean Magnetics Society
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• v.13 no.3
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• pp.121-126
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• 2003

The electromagnetic properties and microstructures of the basic composition of (N $i_{0.2}$C $u_{0.2}$Z $n_{0.6}$)$_{1.085}$(F $e_2$ $O_3$)$_{0.915}$ were invested by changing of the additive Sn $O_2$, CaO amounts and ferrite processes. There is no variation of grain size by changing additive amount. It can reduce the total loss when (N $i_{0.2}$C $u_{0.2}$Z $n_{0.6}$)$_{1.085}$(F $e_2$ $O_3$)$_{0.915}$ composition sintered at 1150 $^{\circ}C$ better than 130$0^{\circ}C$. Additive CaO confirmed of useful addition for the reduce total loss, because it increasing sintering density. Decreasing total loss were observed by adding both Sn $O_2$ 0.06 wt％ and CaO 0.4 wt％.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.193-196
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• 2008

The vortical structures in a turbulent boundary layer (TBL) developed over a flat plate have been investigated experimentally. The flow conditions tested in this study were Re$_{\theta}$ = 3700, Re$_{\delta}$ = 11${\times}$105 and the shape factor H = 1.3. Instantaneous velocity fields in the streamwise-wall-normal planes were measured by using a dynamic PIV system. A trip-wire and sandpapers were placed behind the leading edge to promote the turbulent transition. 1000 velocity fields were obtained consecutively with a time interval of 1 millisecond. Streamwise u-velocity components were temporally averaged in the measuring plane. In addition, 2000 velocity fields were obtained randomly and ensemble-averaged to get the fully-developed turbulent characteristics. Profiles of the normalized u-component, turbulent intensities and Reynolds shear stress were evaluated. The structures of spanwise vortices were extracted from the instantaneous velocity fields by determining the swirling strength, ${\lambda}_{ci}$. The wall-normalized locations of vortices were temporally averaged in the measuring plane with respect to their rotational direction. The correlations between the temporally averaged u and the temporally averaged $y^+$ of vortices were evaluated. For the case of positive vortices, the correlation is not significant. However, the negative vortices show a strong negative correlation. The y-location of negative vortices tends to increase, as the averaged u decreases and vice versa. These findings indicate that the number of negative vortices in the outer layer increases during the outward bursting events.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.81-112
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• 1998

This study reviews the industrialization process of the United States-Mexico Borderlands and the economic relations between the U.S. and Mexico and examines their impact on the borderlands. Main factor in the industrialization of the borderlands was the U.S. investment on the maquiladora program of Mexico since 1965. It contributed to the increase in employment and population of borderlands and the development of service industries. Low wage level of Mexico induced not only standardized labor-intensive industries but also the high-tech automated industries because they still use a lot of labor in manufacturing and assembly process, while the functions of management. R & D, and distribution remained in the U.S. This is a typical case of international division of labor and satellite industrial district. The rules of origin in NAFTA, however forced branch Plants of multinational companies to form the local linkages between firms.

• Animal cells and systems
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• v.16 no.4
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• pp.329-336
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• 2012

This study evaluated ecological health, using various biomarkers and bioindicators, of pale chub (Zacco platypus) as a sentinel species, in Daejeon Stream, South Korea, during AprilMay 2011. The biomarkers and bioindicators were compared among three sites of control: Reference ($C_z$), transition ($T_z$), and the urban zones ($U_z$); and the 7-Ethoxyresorufin-O-deethylase (EROD) activity, DNA damage, acetylcholinesterase (AChE) activity, and vitellogenin (VTG) concentrations were more significantly increased in the $U_z$ than in the $C_z$. Also, physiological markers such as condition factor, liver somatic index, visceral somatic index, and gonad somatic index were significantly increased in the $U_z$ than in the $C_z$. For the health assessments, three categorized parameters of blood chemistry, molecular biomarkers, and physiological bioindicators were standardized and calculated as a star-plot, representing values of Integrated Health Response (IHR). Values of IHR had more significant (P<0.05) increases in the $U_z$ than any other zones, indicating an impairment of ecological health by organic matter, nutrients (N, P), and toxic chemicals. This study is based on low levels of biological organization approach of molecular and physiological biomarkers and bioindicators, so further study of high-levels of biological organization approach such as community and population is required for overall range of health assessments. The approach of IHR values, however, may be useful in providing early warning of future impacts on ecological health.

• Analytical Science and Technology
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• v.17 no.4
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• pp.308-314
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• 2004

When the polymer was used for the guard raw materials of electronic device, the content of U, Th and their daughter nuclides were known as a factor of soft error. Because emitted alpha ray could be caused of mis-operation. And ionic impurities such as Cl, Fe, Na could shorten the device life-time. For the analysis of trace impurities in the polymer, neutron activation analysis(NAA) and ICP/AES have been studied. To improve the accuracy and sensitivity of the trace and ultratrace metallic impurities in the epoxy and phenol polymer, sample pretreatment method and optimum analytical condition of NAA were developed. Using the above method, U, Th and other 23 trace impurity elements were analyzed.

• Korea Real Estate Review
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• v.24 no.1
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• pp.53-62
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• 2014

A test on the significance of style factors which were revealed to be significant in U.S. and U.K. literature is conducted in this study using appraisal-based returns of offices in Korea. Region, size (appraisal value), value-growth propensity (yield gain gap) and leasing conditions (the number of tenants, the length of average leased period and the proportion of key tenant) are included in the analysis model as style factors. The empirical result suggests that firstly core region and large size are significant but they increase risk as well as return contrary to general belief, secondly value propensity significantly decreases risk as well as return as it does in U.S. and U.K., finally the number of tenants among leasing conditions decreases risk as well as return but the length of average leased period and the proportion of key tenant are not significant.

• Journal of the Korea Society of Computer and Information
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• v.28 no.5
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• pp.39-47
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• 2023

The purpose of this study is to examine the progress of negotiations between the two countries regarding the implementation of AFKN's satellite broadcasting on October 4, 1983, as well as the opposition of domestic public opinion, which emerged as an important variable in the negotiation process. Through this, it was intended to lay the foundation for the historical facts necessary to interpret the negotiation process between the two countries over the implementation of AFKN's satellite broadcasting in the context of world history of cultural globalization. As a research method, the historical literature research method was used, focusing on archive documents stored in diplomatic archives. The study revealed that public opinion's movement toward cultural imperialism under domestic political conditions, which had authoritarian control over the media, served as an accidental factor to help carry out the regime's interests of regime protection. Through these findings, this paper interpreted that AFKN-TV's satellite broadcasting, which was implemented under the U.S. Department of Defense plan without the prior consent of the Korean government, clearly shows that Korea has been "semi-forced" into the U.S.-led cultural globalization order.