• The Journal of the Acoustical Society of Korea
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• v.34 no.5
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• pp.385-393
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• 2015

The speed of train has rapidly been increased in accordance with the developed railway technology. Nowadays, high-speed trains were introduced which has the speed faster than 400 km/h. In Korea, a lots of efforts were undertaken to increase the speed of train faster than 350 km/h, however noise and vibration are still the main problems to solve for realization of the high-speed train. In the case of operation speed faster than 350 km/h, it can be easily presumed that the noise and vibration damages could be increased in the train stations which are close to the passing railway tracks. Thus, the noise in the five different types of high-speed train stations were analyzed including stations built on the ground, underground, under rail, and two types on rail. The present paper predicts noises inside the stations depending on the speed of the passing trains and analyze the noise comparing with noise criteria (NC). Sound insulation performance of each part of buildings was calculated using the transmission noise formula and computer modeling, Finally, a series of processes were introduced to satisfy the aural environment with the optimum interior noise criteria by changing interior finishing materials.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.58-65
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• 2019

Polymer concrete is expected to be widely used as a building material because it has a shorter hardening time and excellent compression, tensile, bending, bond strength, frictional resistance and abrasion loss compared to general concrete. The polymer concrete has excellent vibration damping performance and research on the use of various reinforcing materials is being conducted. However, in order to completely replace the general concrete and the general anti-vibration reinforcement, such polymer concrete requires an overall review of vibration reduction performance considering physical properties, dynamic properties, productivity and field applicability. In this study, the physical and dynamic properties of polymer concrete by epoxy mixing ratio were compared with those of general concrete. It was appeared that compression, tensile, bending and bond strengths of polymer concrete by epoxy mixing were significantly higher than those of general concrete. Especially, the tensile strength was more than 4 ~ 6.5 times. Based on the basic physical properties of polymer concrete, the damping ratio, which is a dynamic characteristic according to the epoxy mixing ratio, was derived through analytical models and experiments. As a result, the dynamic stiffness of polymer concrete was 20% higher than that of general concrete and the loss rate was about 3 times higher.

• Journal of The Korean Association of Information Education
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• v.9 no.2
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• pp.197-208
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• 2005

For the wide spread of cyber education, it is important to understand the instructional characteristics of cyber education and its applications in the educational sites which help to cope with the practical needs and problems. This study was conducted to analyze the experience of cyber classes(working hours, tasks and evaluation, satisfaction level and instructional effectiveness, suggestions for cyber education) and use of instructional methodology (instructional activities, interaction frequencies, cooperative learning activities, instructional activities toward knowledge building). The data was collected from pre-service teachers(403) and in-service teachers(318) in June 2004. The results were that pre-service and in-service teachers all consider the satisfaction level and academic achievement level of cyber classes lower than that of FTF classes. Particularly the boring presentation of instructional materials and the inadequate instructional strategies for cyber classes were the biggest complains, and lack of interaction among peer groups and with instructors, lack of learning opportunity for cyber instructional strategies, limited group activities, lack of interaction with experts were followed. Limited types of evaluation also showed that cyber classes focus on results more than the process of students' academic achievement.

• Journal of the Korean housing association
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• v.21 no.2
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• pp.19-30
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• 2010

The aim of this research is to understand the characteristics and status of existing public facilities, in order to propose the necessary basic materials for the planning and development of improved public facilities to assist communities. Objects of this research are the public facilities provided by the Government throughout the 25gu in Seoul. The methods of this research were carried out through the home page of each facility, telephone inquiries and gujung backseo. Investigations were carried out 3 times between the periods of January-June and September in 2009. Results of the research are as follows - 1) Through the investigations of classifications and distribution status of 5 public facilities over 25gu, quantity supply problems were analyzed. 2) Building distributions of 5 public facilities were classified by types and analyzed. 3) A number of compound facilities were classified and analyzed to determine the complexities of the 5 public facilities. 4) Complex types and characteristics of public facilities in 25gu in Seoul were analyzed. Based on the results of the research, the following conclusions are drawn: 1) Public facilities throughout the 25gu in Seoul have common characteristics and functions and they are spread out evenly in each gu. This means that public facilities are standardized in Seoul. Characteristic public facilities suitable to each gu should be planned accordingly. 2) Public facilities in Seoul show a single form of one facility. Therefore, initiative plans for the complexity of facilities are required. 3) Complex public facilities in Seoul need to be the center of community life in each gu. It is necessary to take into account the diverse life styles and classified needs of residents for complex facilities. Based on the research, complex types such as public administrative+cultural facilities, culture+welfare facilities, medical+welfare facilities can be presented. These complex types should not be classified according to any particular use, but they should be commonly used by diverse generations and every social class. The inquiries of users of public facilities and the programs of each public facility are not included in this research. Thus, the reseaarch limits the proposals for complex public facilities. In the future, the characteristics of each gu in Seoul should be studied and understood, so that appropriate public facilities and their complex plans can be researched continuously and necessarily.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.357-367
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• 2017

Bending and axial forces simultaneously occur at the cross-section of a shotcrete lining reinforced with steel supports due to the tunnel geometry. The shotcrete has changing flexural stiffness depending on the axial forces and, as a result, severely nonlinear behavior. The mechanical properties of a shotcrete-steel composite also depend on the type of steel support. This study presents a fiber section element model considering the effect of axial force to evaluate the nonlinear behavior of a shotcrete-steel composite. Additionally, the model was used to analyze the effects of different types of steel supports on the load capacity. Furthermore, a modified hyperbolic model for ground reaction, including strain-softening, is proposed to account for the ground-lining interaction. The model was validated by comparing the numerical results with results from previous load test performed on arched shotcrete specimens. The changes in mechanical responses of the lining were also investigated. Results show a lining with doubly reinforcement rebar has similar load capacity as a lining with H-shaped supports. The use of more materials for the steel support enhances the residual resistance. For all types of steel reinforcement, the contribution of steel supports during peak load decreases as the ground becomes stiffer.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.139-145
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• 2011

Objectives: This investigation is purposed to evaluate the airborne asbestos concentrations in the public buildings having asbestos containing materials(ACMs) in Seoul. Methods: The Seoul Metropolitan Government carried out an asbestos survey to the city-owned public buildings to identify the level of risk exposure, classified into low, moderate and high risk. To evaluate the airborne concentration of asbestos, 11 sampling sites in ten buildings based on the survey were selected. The air samples from the eleven sites were analyzed by Phase Contrast Microscopy(PCM) and Transmission Electron Microscopy (TEM), and compared the analytical results from the both. Results: 1. The airborne fiber concentrations by PCM were less than the detection limit($7f/mm^2$) in 9(82%) out of 11 sampling sites. The highest concentration was 0.0043 f/cc, but it was below the guideline value for indoor air quality(0.01 f/cc), proposed by the Ministry of Environment, Korea. 2. In two sampling sites, having moderate risk level, the chrysotile was identified and showed it's concentrations of 0.0102 s/cc and 0.0058 s/cc, less than $5{\mu}m$ lengths. 3. The ACMs identified in the two sampling sites were a packing material(65% of chrysotile) in mechanical area and a thermal system insulation(5% of chrysotile) in a boiler room. Having more possibility of asbestos emission in the mechanical area, it would be required to set up and carry out the asbestos management plan. Conclusions: Based on the result of this study, the airborne asbestos concentrations in the public buildings with ACMs were generally lower than the guideline value for indoor air quality. There are widespread concerns about the possible health risk resulting from the presence of airborne asbestos fibers in the public buildings. Most of the previous studies about airborne asbestos analysis in Korea were performed based on PCM method that asbestos and non-asbestos fibers are counted together. In the public and commercial buildings, having ACMs, it is suggested that the asbestos be analyzed by TEM method to identify asbestos due to concerns about asbestos exposure to workers and unspecified people.

• Science of Emotion and Sensibility
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• v.9 no.1
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• pp.63-75
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• 2006

This is a basic research aimed at enhancing a brand image by unifying color images of a brand at both online and offline stores. h survey was conducted on color images of online and offline stores to measure the level of consistency between consumers' perception of the color image and the brand's color strategy. A brand preference survey was also performed to shed light on the relationship between the brand preference and the consistency of color images at online and offline stores. This study is committed to building an effective color strategy, based on the brand strategy, through web color planning that is consistent with the offline color image. This paper started with a specific purpose of devising solutions in regard to the prior study, entitled 'Study on Color Strategies in Brand Coffee', which recognizes the need for consistent color images, or integrated color strategies, in online and offline stores. I specifically took the approach of looking at color planning in the stage of designing a website. Two standards were used to analyze emotional and functional aspects of color images: color grading by I.R.I and five communicators of color information by Rouge. Direct visits were made to the offline stores for surveys to address the shortcomings of the prior study, in which offline stimuli were limited to printed materials. The direct visits enabled a study of an overall color image of the offline stores, while providing a set of substantial and specific guidelines for designing colors for a website. I hope this study goes a long way toward enhancing the level of consistency between online and offline color images based on the brand's unique color strategy, and thereby improving the overall level of brand image.

• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.41-48
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• 1985

In near future about 500,000 hectares of Japanese larch and pitch pine need thinning to improve crop-tree spacing and reasonable species composition in Korea. Although thinned trees show very little high quality wood, in fact, all the sawed products are suitable for construction and farming materials. Studies on the utilization of thinned small-diameter trees have been implemented in order to increase lumber yield and display the skeleton of farm buildings. The results obtained in this study were summarized as follows: 1. According to Korean Conifers Log Grading System, log grade 3 was 87.4 percent in Japanese larch bolts and 95.8 percent in pitch pine bolts from thinned trees. The ability to identify defects was essential for grading logs. 2. Cutting diagrams of sawing were developed for 1-sided sawing, 2-sided sawing and 3-sided sawing by small end diameter class of bolt and cutting sizes also were found to use effectively lumber with wane. 3. Lumber recovery of Pitch pine was a little higher than that of Japanese larch. The maximum lumber yields of pitch pine by sawing patterns were 87.2 percent for 1-sided sawing, 80.8 percent for 2-sided sawing an 64.1 percent for 3-sided sawing, up yield compared with 58.1 percent for 4-sided sawing. The lumber yield of 1, 2 and 3-sided sawing significantly was higher value than that of 4-sided sawing. 4. Lumber was inspected and graded. Lumber quality of diameter class 12cm was a little better than that of diameter class 8cm, but 90 percent of lumber in diameter c1ass 16cm fell into grade 3. The lumber grade was classified by Korean standard grades of confiers lumber. 5. Lumber from 1, 2 and 3-sided sawing was used to build the skeleton of a farm house ($53m^2$) and greenhouse ($60m^2$) in order to display more efficient use of small diameter trees from thinning 6. Total volume of timber for building a farm house was $8.1m^3$ of imported timber. Timber of $7m^3$, 70 percent of total volume would be substituted imported timber for domestic timber.

• Korean Journal of Oriental Medicine
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• v.18 no.2
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• pp.1-16
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• 2012

Objectives : The 10th Conference of the Parties to the Convention on Biological Diversity (COP 10) was held in Nagoya, Japan in October 2010, during which an international convention on access to genetic resources and conventional knowledge and sharing of benefits thereof was adopted. The Oriental Medicine field uses medicinal herbs based on genetic resources, as well as traditional knowledge about genetic resources. As such, if Korea, China and Japan compete over the ownership of such traditional knowledge, it will almost certainly trigger disputes over the payment of royalties among other problems. Notably, since the traditional medicine industry is closely related with China, it is highly likely this will adversely affect Korea's production of medicines using natural materials, including Korean herbal doctors' prescription, formulation and preparation of medicinal herbs. Methods : This study also analyzed the recent situation in Japan, which is the chair nation of the Nagoya Protocol and a member nation like Korea. It analyzed the Japanese people's awareness of the Nagoya Protocol and its strategies in the two years since its adoption, as well as the Guidelines for Genetic Resources, which were newly revised in 2012. Conclusions : The Nagoya Protocol requires the preparation of legislative and administrative measures and policies in order to pave the way for sharing the benefits deriving from the use of genetic resources and the relevant traditional knowledge with the providers of such resources. Thus, corresponding domestic legal measures need to be taken. Such measures include the refining of the procedure of accessing genetic resources, the designation of liaison offices, a competent agency and a supervisory agency, and the building of a system designed to issue internationally acknowledged certificates. It is also important to operate related professional consulting offices, as is the case in Japan. In addition, in the case of genetic resources, there is a need to seek multinational and bilateral cooperation including free trade agreements. Regarding traditional knowledge about genetic resources, measures need to be prepared to enable the three East Asian countries, namely, Korea, China and Japan, to commonly use ancient literature on Oriental medicine and to claim exclusive rights to such intellectual properties. Notably, with China now moving to expand the scope of traditional knowledge through the WIPO, Korea needs to prepare response measures.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.2
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• pp.75-84
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• 2018

Thermal stress of livestock has been issued due to recent climate change trends and this causes reproductive disorders, decreased feed consumption, immunosuppression, and increased mortality of animals. Concept of THI has been widely used to quantitatively evaluate the degree of thermal stress for animals, however use of this concept is restricted for animals living in the enclosed facilities such as mechanically ventilated broiler houses. In this study, time-based internal energy flow and variation trends of temperature and humidity were analyzed based on BES technique. Local weather data, insulation characteristics of building materials, heat and moisture generation rate from broilers according to age, algorithm of ventilation operation were adopted for boundary condition of the model to accurately compute THI values inside the mechanically ventilated broiler house. From the BES computation, excess frequency of THI threshold in Jeju city was highest on the assumption that air conditioning equipments were not installed. When general raising density ($39kg\;m^{-2}$) was adopted, total 2,191 hours were exceeded. Excess hours of THI threshold were strongly related to the cumulative air temperature ($R^2=0.87$).