• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.83-90
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• 2020

Plate heat exchangers(PHE) have been commercialized since the 1920s. Since then, although the basic concept of PHEs has changed little, its design and construction have progressed significantly to accommodate higher temperatures, higher pressures, and large heat exchanging capacities. The development trend of PHEs is consistent with heat plate developments with better thermal efficiency, lower pressure drop, and good flow distribution. The purpose of this paper is to introduce the main development processes of a plate cooler for medium-speed engine lubricant oil cooling in vessels which is in line with the development trend of PHEs and to provide its thermal performance data that were found out during experimental tests. The plate cooler in this study cannot measure the wall temperatures directly due to its structural characteristics, so the heat transfer coefficients were calculated using the modified Wilson Plot method. The water-to-water tests were first conducted experimentally to figure out the characteristics of heat transfer coefficients and pressure drops on the water side and then the water-to-oil tests followed to obtain the heat transfer coefficients on the oil side. The test results showed that heat transfer coefficients and pressure drops on both water and oil side increased with flow rates, and it was also found that all the development targets of the plate cooler in this study were achieved successfully.

• Journal of Distribution Science
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• v.11 no.4
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• pp.23-35
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• 2013

Purpose - This paper attempts to identify the problems and limitations of a market maintenance project conducted according to the 「Special Act for the Development of Traditional Markets and Shopping Street」 and to present a revised direction for the special law and lay the groundwork for market maintenance projects to be promoted smoothly. Research design, data, and methodology - The revised direction for the legislation and the proposal were written based on an investigation of the problems and the legal system, and proposed measures for market maintenance operation and system improvements to derive the improvements needed for market maintenance projects. Results - A market maintenance project has been conducted as a means to reinvigorate traditional markets that are economically depressed, and to revive the local economy. It was largely conducted in the form of reconstruction and redevelopment and represents the interests of landowners and merchants. Thus, it is most likely to contribute to the gradual disappearance of traditional markets. First, as part of a market maintenance project, many companies are building multipurpose buildings or high-rise residential buildings to increase profits. In these high-rise buildings, they can raise rents, which may not be affordable for some existing small businesses. To solve such problems, the large-scale store registration requirement needs to be relaxed or abolished once the market maintenance project is completed. If the large-scale store registration requirement is to be abolished, the term 'large retail store' should be changed in the 「Special Act for the Development of Traditional Markets and Shopping Street」. After registration, the Small and Medium Business Administration should train merchants, offer consultations, and support events, to the extent that the existing traditional market management modernization project permits, and further continue to manage and support its ongoing activities. However, unless large-scale store registration is abolished, adding an exception clause in the special law to relax large-scale store registration criteria, and permitting changes to building use is another option. At the end of a market maintenance project, empty stores should be purchased by the Small and Medium Business Administration, and local government, etc., at the actual construction cost, to utilize them as public rental shopping areas, which in turn may be re-utilized as a temporary market for another market maintenance project. The second problem in market maintenance projects is merchant-protection. Currently, the special law prescribes that a temporary market be created for merchants to conduct business during the rental period of a market maintenance project. Conclusions - In reality, a market maintenance project is conducted usually in big metropolitan cities with 500,000 residents or more. The main building type created under these projects is a multipurpose building. For this reason, it is very difficult to secure a location for a temporary market in the surrounding area of such a project. To solve this problem, this study suggests 'public rental shopping areas' as mentioned above.

• Journal of Distribution Science
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• v.11 no.4
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• pp.89-97
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• 2013

Purpose - The purpose of this study is to systematically review the background of the Korean distribution promotion policy and distribution adjustment policies along with related regulations and policies. Research design, data, and methodology - Domestic distribution policy and relevant laws were examined through a review of existing research literature. The results of the development process of the domestic distribution policy, promotion policies, and adjustment policies are summarized below. Results - The results are summarized as follows. First, the purpose of the development of the domestic distribution promotion policy was to strengthen the competitiveness of the small and medium business industry through structural advancement of the small and medium industry. By expanding the managerial base for the small and medium industry, a new balance could be created in the national economy. There was a requirement for an early assistance policy for small and medium businesses as a base of these businesses in the distribution industry developed from their original model of catering to a traditional market of retail shops. Since 1996, there was a need for this early assistance policy due to the expansion and rapid growth of large scale stores causing a change in the consumption pattern for distribution markets and the decline of large enterprises. Second, the government supports small and medium business distribution through distribution promotion policies by supporting an organization promoting small business and supporting innovation in the distribution system. Third, in 1961 a business mediation system was established to protect small and medium industries. The Small and Medium Business Administration advises conglomerates to postpone acquisitions, restrain expansion of the business, or to reduce business scale if small businesses undergo an adverse effect such as decreasing demand because large companies are expanding into their areas. Fourth, the Distribution Adjustment Policy managed large-scale store regulation as follows: ① limitation on construction by urban planning ordinance, ② limitation on location based on traffic impact assessments, ③ regulation based on business guidelines by chiefs of autonomous bodies, ④ regulation on mandatory holidays and limitation of business hours. This large-scale store regulation is a policy introduced by authority to increase competitiveness of small and medium business distribution by the government. Conclusions - As discussed in this study, the distribution promotion policy and distribution adjustment policy are government distribution policies focused on the protection of the small and medium distribution businesses. This study is timely, since it was planned when the strengthening of the revisions of the Distribution Industry Development Act, aimed to protect small and medium retailers and merchants, was under discussion. The significance of this study is that it offers insights for the development of new policies in the future and an opportunity to consider the background of the distribution policy by the government.

• The Journal of Industrial Distribution & Business
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• v.9 no.8
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• pp.51-60
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• 2018

Purpose - Civil affairs are increasing in various forms, but civil servants who are able to handle them want to reduce the complaints and provide keywords that will help in the future due to their lack of time. While various ideas are presented and implemented as policies in solving civil affairs, there are many cases that are not policies that people can sympathize with. Therefore, it is necessary to analyze the complaints accurately and to present correct solutions to the analyzed civil complaint data. Research design, data, and methodology - We analyzed the complaints data for the last three years and found out how to solve the problems of Yongin City and alleviate the burdens of civil servants. To do this, the Hadoop platform and Design Thinking process were reviewed, and proposed a new process to fuse it. The big data analysis stage focuses on civil complaints - Civil data extraction - Civil data analysis - Categorization of the year by keywords analyzing them and the needs of citizens were identified. In the forecast analysis for deriving insights, - The case of innovation case study - Idea derivation - Idea evaluation - Prototyping - Case analysis stage used. Results - Through this, a creative idea of providing free transportation cards to solve the major issues of construction, apartment, installation, and vehicle problems was discovered. There is a specific problem of how to provide these services to certain areas, but there is a pressing need for a policy that can contribute as much as it can to the citizens who are suffering from various problems at this moment. Conclusions - In the past, there were many cases in which free traffic cards were issued mainly to the elderly or disabled. In other countries, foreign residents of other area visit the areas for accommodation, and may give out free transportation cards as well. In this case, the local government will be able to set up a framework to present with a win-win scenario in various ways. It is necessary to reorganize the process in future studies so that the actual solution will be adopted, reduce civil complaints, help establish policies in the future, and be applied in other cities as well.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.730-743
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• 1997

Community structure and distribution patterns of benthic polychaetes were studied in Aug. 1983 and Feb. 1984 in Kwangyang Bay, Korea. During the study period, the large-scale reclamation and dredging operations were taking place. Polychaetes were composed of 76 species with a mean density of $342\;ind.{\cdot}m^{-2}$ during the summer 1983 and 77 species with a mean density of $437\;ind.{\cdot}m^{-2}$ during the winter 1984. Community structure indices were applied to the seasonal data. The stations influenced by the Seomjin river are characterized by a low species number and low diversity, while the stations located in channel regions represent high species richness and highdiversity. The inner bay stations showed the intermediate level in terms of species richness and diversity. On the basis of taxa composition and abundance in summer, the cluster analysis indicated that the study area was divided into live regions. The main factors that govern the polychaete distributions appeared to be the fresh water run-off and bottom sediment composition. However, a slight difference was observed in winter community, and changes in composition of the dominant species were found from Lagis bocki and Chone teres to Glycinde gurjanovae and Heteromastus filiformis. As a result, the broad scale reclamation and dredging activities may have played a role in changes of the polychaete community structure and the dominant species composition in Kwangyang Bay.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.723-734
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• 2010

To understand temporal variations in geochemical characteristics of intertidal surface sediments around Byeonsan Peninsula (in the middle of the western coast, Korea) after the construction of Saemanguem dyke, the sedimentation rate and various geochemical parameters, including mean grain size (Mz), water content (WC), ignition loss (IL), chemical oxygen demand (COD), and acid volatile sulfide (AVS), were measured along four transects (A.D lines) at monthly intervals from February 2008 to March 2009. The average monthly sedimentation rate ranged from -5.3 to 3.8 mm/month (mean $-0.8{\pm}2.7\;mm$/month), which showed an erosion-dominated environment in the lower part of the intertidal zone. In addition, surface sediments were eroded in summer and autumn, but were deposited in spring and winter. The Mz of surface sediments ranged from -0.8 to $3.4{\varnothing}$ (mean $2.8{\pm}0.5{\varnothing}$), indicating that the surface sediments consist of coarser sediments (sand and slightly gravelly sand). The Mz of surface sediments did not show large monthly and/or seasonal variations, although the sedimentation rates of surface sediment showed large seasonal variation. This may be due to lateral shifting and effective dispersion of surface sediments by wind, tide, and longshore current. The concentrations of IL and COD in the surface sediments ranged from 0.2 to 2.9% (mean $1.4{\pm}0.4%$) and from 0.2 to $18.5\;mgO_2$/g-dry (mean $3.9{\pm}3.4\;mgO_2$/g-dry), respectively, which were slightly higher in spring than in the other seasons. This may be related to spring blooms of phytoplankton in seawater and/or benthic microalgae in surface sediments. On the other hand, no AVS concentrations were detected in surface sediments at any of the sampling stations during the study period.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.181-194
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• 2020

Due to the changes in the distribution market, issues related to storage and distribution of agricultural, aquatic and livestock products, and storage and transportation of processed and fresh food are rapidly emerging, and as a result, Cold Chain is naturally receiving attention as one of the logistics services. The purpose of this study is to evaluate the competitiveness of location in the construction of a cold chain cluster centered on the metropolitan area, which has attracted attention in relation to the distribution of cold chains, such as recently refrigerated frozen foods. To this end, this study evaluated the competitiveness of cold chain cluster candidates in the metropolitan area by utilizing the CFPR (Consistent Fuzzy Preference Relations) method that can efficiently extract and quantify expert knowledge. As a result, the location competitiveness was found to be superior to Incheon New Port's hinterland, Gyeonggi South Area (Yongin), Gyeonggi West Area (Gimpo Logistics Complex), and Pyeongtaek Oseong Logistics Complex. In particular, this study extracted the knowledge of refrigerated and refrigerated logistics warehouse operation experts, and conducted detailed competitiveness assessments for cold chain cluster candidates in the metropolitan area, and suggested the optimal cluster candidates. In the future research, it is necessary to classify the questionnaire into the owner, large business group, and public business group, etc., who have the right to purchase and build to secure ownership of the fresh food distribution center.

• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.527-534
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• 2006

This paper outlines a new strengthening technique for concrete beams using externally unbended high-strength bars. The advantages of proposed method lie in speed and simplicity of construction compared to the alternative strengthening method. Externally unbended reinforcement retains many of the advantages over external unbended prestressed tendons. It eliminates time consuming stressing operations. Clearance requirements around anchorages are reduced as access is not required for prestressing jacks. Test results of eight specimens on reinforced concrete beams using different reinforcement materials such as carbon fiber sheet, steel plate and high-tension bar are reported. The beam strengthened by carbon fiber sheet showed a brittle failure mode due to the separation of fiber. As a result of draped profile of external bar, the maximum strength of the beam were increased by up to 212 percent and the deflections were reduced by up to 65 percent. Test results show that the beams reinforced with high-tension bar are superior to reference specimens, especially for the strength and deformation capacity.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.711-718
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• 2010

The requirement of the maximum yield strength of shear reinforcement in the KCI-07 code is quite different to those in the ACI-08 code, EC2-02, CSA-04, and JSCE-04 codes. Eighteen RC beams having high strength shear reinforcement were tested. Test results indicated that even if the yield strength of shear reinforcement in beams was much greater than the maximum yield strength required by the KCI-07 design code, the shear reinforcement of these beams reached their yield strains. Furthermore, the shear strengths of tested beams increased almost linearly with the increase of the amount of shear reinforcement. In addition, larger numbers of diagonal cracks developed in the web of the beam having greater yield strength than the beams having lower yield strength of shear reinforcement. The maximum crack width of the beam having high strength shear reinforcement was approximately the same to the crack with of the beam having normal strength shear reinforcement.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.97-110
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• 2007

A laser scanning technique has been attracting much attention as a new technology to acquire location information. This technique might be applicable to a wide range of areas, most notably in geomatics, due to its high accuracy of location and automation of high-density data acquisition. A alignment information extraction system on highway has been developed in this study by utilizing the advantages of the laser scanning technique. The system can accurately interpret the alignment information of highway and can be applied to actual works. To develop the alignment information extraction system on highway, an algorithm that can automatically separate a horizontal alignment into a straight line, a transition curve, and a circular curve was developed. It can increase its efficiency compared to the conventional methods. In addition, an algorithm that can automatically extract design elements of horizontal and vertical alignments of highway was developed and applied to an object highway. This yielded higher practicality with more accurate values compared to those from previous studies on the extraction of design elements of highway alignment. Furthermore, the extracted design elements were used to perform a virtual driving simulation on the object highway. Through this, data were provided for a visual judgment for judging visually whether the topography and structures were harmonized in a three-dimensional manner or not. The study also presents data that can serve as a basis to determine highway surface freezing sections and to analyze three-dimensional sight distance models. Through the establishment of a systematic database for diverse data on highway and the development of web-based operating programs, an efficient highway maintenance can be ensured and also they can provide important information to be used when estimating a highway safety in the future.