• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.77-84
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• 2013

Degree-day method is very simple but essential index to estimate heating and cooling energy demand in buildings. It has been neglected, however, for the simplicity so it is difficult to find any DB for south Korean cities. Even meteorological department of S. Korea doesn't report the data officially. In this study, current methods that are being used in many countries are investigated and used to calculate degree-days of 35 south Korean cities with 30 years(1981~2010) historical data. The calculation result indicates that the error among 4 major methods are dependent on how daily or hourly temperature are treated in the calculation and how balance point temperature is defined. The errors of the methods are no larger than 6% relative to hourly degree-day method.

• Composites Research
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• v.32 no.6
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• pp.382-387
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• 2019

A single frequency strain mode test, a stress relaxation mode test, and a creep test using RH-DMA were performed to investigate the effects of relative humidity and temperature on the viscous properties of PET film. The relative humidity was 10%, 30%, 50%, 70%, and 90%. The temperature was considered to be 30~95℃ for single frequency strain mode tests, 30℃ and 70℃ for stress relaxation mode test, and 5~95℃ for creep test. According to the results, higher relative humidity results in lower storage modulus and loss modulus, but the maximum value of the loss modulus is not significantly affected by changes in relative humidity and is almost constant. Relaxation modulus decreases rapidly at the beginning and becomes constant, and as the temperature increases, it is susceptible to changes in relative humidity. Strain recovery also increases rapidly at the beginning and is susceptible to changes in relative humidity as the temperature increases. In addition, as the temperature increases, the degree of increase in creep compliance increases, and as the temperature rises above the glass transfer temperature, the degree of increase becomes very large. The master curve determined by the time-temperature superposition provides the information to predict the long-term performance under operating conditions such as relative humidity and temperature.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1845-1865
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• 2019

Current Internet is designed by lots of service providers with different objects and policies which make the direct deployment of radically new architecture and protocols on Internet nearly impossible without reaching a consensus among almost all of them. Network virtualization is proposed to fend off this ossification of Internet architecture and add diversity to the future Internet. As an important part of network virtualization, virtual network embedding (VNE) problem has received more and more attention. In order to solve the problems of large embedding cost, low acceptance ratio (AR) and environmental adaptability in VNE algorithms, cognitive method is introduced to improve the adaptability to the changing environment and a cognitive virtual network embedding algorithm based on weighted relative entropy (WRE-CVNE) is proposed in this paper. At first, the weighted relative entropy (WRE) method is proposed to select the suitable substrate nodes and paths in VNE. In WRE method, the ranking indicators and their weighting coefficients are selected to calculate the node importance and path importance. It is the basic of the WRE-CVNE. In virtual node embedding stage, the WRE method and breadth first search (BFS) algorithm are both used, and the node proximity is introduced into substrate node ranking to achieve the joint topology awareness. Finally, in virtual link embedding stage, the CPU resource balance degree, bandwidth resource balance degree and path hop counts are taken into account. The path importance is calculated based on the WRE method and the suitable substrate path is selected to reduce the resource fragmentation. Simulation results show that the proposed algorithm can significantly improve AR and the long-term average revenue to cost ratio (LTAR/CR) by adjusting the weighting coefficients in VNE stage according to the network environment. We also analyze the impact of weighting coefficient on the performance of the WRE-CVNE. In addition, the adaptability of the WRE-CVNE is researched in three different scenarios and the effectiveness and efficiency of the WRE-CVNE are demonstrated.

• Journal of the Korean Geotechnical Society
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• v.22 no.4
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• pp.85-94
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• 2006

Triaxial tests at isotropic confining pressure of 200 kPa were carried out to show the undrained shear behavior of artificially cemented sands, which were cemented by gypsum, and the influences of relative density and DOC (degree of cementation) were investigated from the results. The yield strength, the elastic secant modulus at yield point and the peak frictional angle of cemented sands increased abruptly compared to uncemented sands, and it was checked that cementation exerts more influence on the behavior of sand than the relative density. But after breakage of the cementation bonds, the relative density was more important factor on the behavior of sand than the cementation. Because the compressibility md the excess pore pressure of cemented sands were reduced due to the cementation bonds, the effective stress path of cemented sands was going toward to the total stress path of uncemented sands. The cementation of sand restricted the dialtion of sand at the pre-yield condition, but induced more dilation in the post-yield condition.

• Journal of the Korean Institute of Navigation
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• v.17 no.4
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• pp.43-51
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• 1993

The purposes of this study are to make an analysis the sensible degree in Korea by using the formulas prepared by Watanabe, and to divide the climatic classification by the sensible degree in order to apply in practical life. Most data(air temperature, relative humidity, wind velocity, atmospheric pressure) are extracted from the "Climatic Table of Korea, Volume II(1961~1990)" issued by the Korea Meteorological Administration. As a result of this study, distribution patterns of the sensible degree are similar to isotherms when the wind velocity is zero, and then the sensible degrees are reduced with the increase of latitude. And western coastal and inland regions have larger values than eastern coastal regions in summer. However, the cont-rary distributions are shown in winter. When the wind velocity is not zero, distribution patterns of the sensible degree are influenced by the wind velocity. In summer, the values of central and southern inland regions are especially higher than the coastal regions, and most northern districts and some inland regions (Kangnung, Ulchin, Yongju etc.) have low values in winter. Then, the climate of Korea is divided into four patterns as follows : Yow means the sensible degree when the wind velocity is zero in winter. Yow > 3 : Jeju Island and southern coastal regions Yow = 0~3 : Most southern district and eastern coastal regions of central districts Yow = -3~0 : Most central districts and some eastern coastal regions (Hamheung, Youngheung, Won-san etc.) of northern districts Yow < -3 : Most northern districts and some inland regions(Inje, Hongcheon, Yang-pyeong etc.) of cent-ral districts.districts.

• Journal of the Korean Home Economics Association
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• v.41 no.3
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• pp.165-180
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• 2003

The number of the functionally disabled elderly has been increasing in Korea and their families should have been in charge of supporting and taking care of them. This study was designed to grope for devices which were helpful to improve the psychological welfare of the functionally disabled elderly in the present situation. The results of this study were as follows: First, considering the level of psychological welfare of the functionally disabled elderly, the depression degree of the subjects was 52.9 which was higher than the middle point, 50. And the degree of family support the functionally disabled elderly were aware of, it also was high ; the score was 34.6 compared to the middle point, 33. On the other hand, the degree of public support that the functionally disabled elderly received was 2.01 which was lower than the middle point, 4.5. Second, the level of the depression of the functionally disabled elderly followed by background variables, the degree of agreement with family support, and public support represented significant differences among group according to religion, the type of previous occupation, the ownership of house, the type of residence, the presence of spouse, education level, and the source of income. Third, the relative influence toward the depression of the functionally disabled elderly was shown in the order of importance as follows: family support, the degree of functional disability, the ownership of house, public support, the presence of spouse, the source of income, the number of daughters, the degree of functional disablity.

• Journal of Labour Economics
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• v.34 no.2
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• pp.1-27
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• 2011

This paper analyzes the demand and supply structure of the market for college professors, and then characterizes the changes in the economic status of them for the last three decades. On the supply side, the number of Korean recipients of doctorate degrees from the U.S. institutions, relative to the number of newly hired professors, has declined dramatically since early 1990s. The relative remuneration of professors, which is found to be closely related to the 'number of students per professor', has also declined steadily. These suggest that the decline in the relative wage of professors has been a driving force for the decline in the relative size of new PhD's in the U.S.

• Korean journal of food and cookery science
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• v.23 no.1 s.97
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• pp.124-139
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• 2007

This study was conducted to evaluate the degree of value assigned to traditional Korean foods by residents from the Kyunggi(n=582) and Kangwon(n=189) areas of Korea. We determined the degree of value for 13 items classified as traditional Korean foods by asking subjects to score the items based on a 5 point Likert scale. Based on the total scores, resident in Kyunggi assigned Kimchi the high degree of value. Next was Tteok, then Eum-cheong, Jang, Hankwa, Muk, Bap, Jeon, Namul, and Guk, respectively. In the Kangwon area, the total scores showed that Kimchi also had the highest degree of value, followed by Tteok, Jang, Hankwa, Eum-Cheong, Muk, Bap, Namul, Jeon and Myeon, respectively. The female residents in Kyunggi gave Kimchi a higher degree of value than the male residents'. Also, subjects with overall higher positive perception of traditional foods had a higher degree of value for Kimchi. Relative to age, ther was a trend showing older subjects had a higher degree of value for Kimchi than Younger subjects. In the case of the head of the family, residents of the Kangwon area showed a trend toward a high degree of value for Kimchi. The residents in Kyunggi, compared to the residents in Kangwon, evaluated the Jang food group as inexpensive foods(p<0.05). However, there was no significant difference between the residence areas for the total score of the items. Overall, the resident's evaluation of the degree of value traditional Korean foods increased with increasing age.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.164-173
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• 2012

Landing ship tank with well dock has the important mission transferring troops or landing equipments from sea to shore. Such transfers are usually carried out using landing crafts, which are loaded or unloaded in flooded well dock. In this situation, as relative motions are occur between well dock and landing craft, safety verifications are demanded. In this paper, seakeeping and safety performances are investigated through model test. First of all, well dock dimensions are reviewed and model tests are performed with sea state 3&4 in 180degree wave direction. Model tests are conducted for three relative positions and seakeeping performances are investigated each position.

• Journal of the Korean Home Economics Association
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• v.35 no.4
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• pp.243-256
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• 1997

The purpose is to measure the level of quality of life and find the degree of importance of various elements of life domains taking into the area of residence and sex account. this paper is assuming that quality of life is a function of not only of the level of satisfaction but also of the relative importance of the elements. An instrument based on previous research was applied to 686 respondents living in Kyungsan area. Regression analysis indicates that the relative importance of the elements differes between the area of residence as well as the sex of the respondents. Similarities and differences between those factors are discussed and policy implications are porvided.