• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.451-456
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• 2014

Lab scale experiment was carried out to study biological wastewater treatment technology developed for shipboard. RCM process using BM(Beneficial Microorganisms) was investigated for practical application on shipboard sewage treatment. RCM process is an environmental friendly treatment system, with minimum production of sludge. In the test, BOD5, CODcr, T-N and T-P were reduced a 96%, 97%, 78% and 81.68% respectively. From the result it was suggested that RCM process with BM might be a suitable process for shipboard sewage treatment, maintenance of useful microorganisms and creating special environment as the SDC tank is circulating in the non-biodegradable organics sludge generated during the wastewater treatment, thus reducing the amount of sludge generated. Therefore, the RCM process does not require additional equipment to strengthen it to meet the marine pollution standards.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1458-1464
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• 2007

Today, domestic and foreign manufacturing industries have to cope with obsolescence of manufacturing equipment because the shifting market trends drive the rapid changes in the production process resulting in stressful operation. Quality control process for manufacturing and production involves a familiar step - when the production process is completed, every item is subjected to various routine tests to determine that it meets the minimum quality standards. Typically, when a faulty product is found, the production line has to be stopped and the current batch is marked for further inspected and exhaustive testing. In this research, we propose a quality monitoring system for productivity enhancement. Our approach aims to reduces the operational down time in the production line of a car-component factory. The proposed monitoring system for productivity enhancement is designed to collect the data through testing at each phase of the assembly line and uses predictive methods on the collected data to achieve early detection of faults in the production process and minimize the number of products in a faulty batch thus minimizing the losses incurred from defective products. More importantly, this system aims to forecast and proactively detect faults and activate warnings when they are detected thus minimizing items in the defective batch, reducing the damage to manufacturing equipment and ultimately reducing the operational downtime or the delay in the resumption of normal factory operation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4C
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• pp.321-329
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• 2008

H.264/AVC video coding standard enables a considerably higher improvement in coding efficiency compared with previous standards such as MPEG-2, H.263 and MPEG-4. To achieve this, for each macro-block in H.264/AVC, Rate-Distortion Optimization (RDO) technique is employed to select the best motion vector, reference frame, and macro-block mode. As a result, computational complexity is increased significantly whereas RDO achieve higher improvement. This paper presents fast intra mode selection algorithm based on constraints of frequency characteristics which are derived from intra coding modes of H.264/AVC. First of all, we observe the features of each intra mode through the frequency analysis of image. And then proposed Frequency Error Costs (FECs) are calculated to select the best mode which has minimum cost. Computational complexity is considerably reduced because rate-distortion costs only calculate the candidate modes which are set of best mode and its neighbouring two modes. Experimental results show that proposed algorithm reduces the complexity dramatically maintaining the rate-distortion performance compared with H.264/AVC reference software.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.11-20
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• 2014

The behaviors and stability of reinforced subgrade with short geogrid were examined and evaluated during construction. First of all, analytical approach for the minimum length of geogrid was performed to guarantee stability during construction loading state. Secondly, the economic aspects for reinforced subgrade were compared with between domestic standards applying with 0.7 H reinforcement length and new way to mix short and long reinforcement. Full scale railroad subgrade was constructed with the size of 5 m high, 6m wide, and 20m long to verify the stability of the subgrade with the length of 0.3 H, 0.35 H, 0.4 H reinforcement. Total 51 sensors were installed to measure settlement, bulging, and the change of stress of the subgrade. It is concluded that the reinforced subgrade with short(0.35H, 35% of height) geogrid had stability within allowable level of deformation and stress increment during construction.

• Tribology and Lubricants
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• v.31 no.2
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• pp.69-77
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• 2015

Recently, there have been reports of severe symptoms of wear in bearings due to foreign substances mixed in lubricants. Therefore, studying the effects of foreign substances (such as combustion products and metallic debris) on the wear characteristics of journal bearings and proposing appropriate management standards for lubricant cleanliness have become necessary. Studies on the effect of particle size and concentration of foreign substances on surface damage have actively progressed in the recent times. These studies indicate the possibility of foreign substances causing direct wear of bearing surfaces. However, experiments conducted until now involve only basic tests such as the Pin-on-Disk test instead of those involving real bearing systems. This study experimentally examines the damage to the surface of a journal bearing due to foreign substances (combustion products and alumina) mixed with the lubricant, as well as the effect of the type and size of particles on its wear characteristics. The study uses an experimental journal bearing similar to a real bearing system for conducting the lubrication test. Hydrodynamic Lubrication (HL) numerical analysis, experiment results, and film parameters are used for calculating the operating conditions required for achieving the desired film thickness, and the results of the analysis are modified for considering the surface roughness. The run-time of the experiment is 10 min including the stabilization process. The experiment results show that alumina particles larger than the minimum film thickness cause significant surface damage.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.507-518
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• 2021

The application of an adhesive calcium carbonate-based hybrid insulation board with quasi-combustibility in the external thermal insulation composite system(ETICS) ensures effective thermal performance and fire safety. This study aimed to conduct a mechanical test of the quasi-non-combustible hybrid insulation board as well as its constituent materials to obtain the basic data for the structural design of the adhesive ETICS. Test specimens were fabricated based on domestic and foreign test standards to examine and evaluate their tensile, compressive, flexural, and shear strengths. The strength characteristics of the quasi-non-combustible hybrid insulation board were identified from the test results, which verified that the minimum required physical properties suggested by the current KS M ISO 4898 were met. Furthermore, the quasi-non-combustible ETICS used in this study was found to be suitable for use as an external insulation system for walls unless subjected to continuous gravity load, such as a heavy exterior finish.

• Journal of the Korean Solar Energy Society
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• v.39 no.5
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• pp.11-28
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• 2019

Governments are increasing energy efficiency in buildings through various policies to reduce building energy consumption. In 2002, the European Union adopted a building energy performance guideline to set minimum efficiency standards for residential and commercial buildings. Starting in 2020, all EU member states should ensure that all buildings are Near-Zero Energy Buildings (NZEB). In Korea, the government issued a zero-energy certification system. Since 2020, public buildings are required to cover energy consumption with the energy produced in buildings. As the demand for building energy simulation has increased to increase the energy efficiency of these buildings, the International Standard Organization (ISO) has created a standard for calculating building energy requirements called ISO 13790. This standard was revised to ISO 52016 in 2017. In this research, ISO 13790, which calculates the energy needs of existing buildings, and ISO 52016, which replaces them, are compared and analyzed, and applied to the calculation of heating energy needs of buildings. For models without thermal zoning(Case A), the difference in annual heating energy needs calculated from each criterion is $1.08kWh/m^2$, which is about 2% higher in ISO 52016. In the case of the thermal zoning model(Case B), the difference in annual heating energy needs calculated by each standard was $0.97kWh/m^2$, which was about 2% higher than ISO 52016. The heating energy needs model without thermal zoning has a higher energy needs than the heating energy needs model with thermal zoning. It is about 16% energy at $8.58kWh/m^2$ for ISO 13790 and $8.69kWh/m^2$ for ISO 52016.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.4
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• pp.27-34
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• 2018

Flat or Multiple Dwelling Houses are relatively vulnerable to crime safety. Crime prevention measures are urgently needed because crime is 2.6 times higher than in real apartments. Through the analysis of domestic and foreign crime prevention design standards, field survey, and interviews with experts, 27 items of crime prevention design criteria for flat or multiple dwelling house were derived, and ten design criteria that should be considered first by the expert AHP were derived. As a result of the pilot evaluation of existing flat or multiple dwelling house, the houses completed after 2015 have relatively high level of crime prevention, but the houses constructed before that are very vulnerable. The policy and system improvement plan based on the analysis result is as follows. First, new housing should be promoted to meet minimum criteria by supplying and educating public officials, architects, and building owners in the short term to provide criteria for flat or multiple dwelling house crime prevention plans. Second, existing housing should be supported with basic crime prevention support projects such as security windows for flat or multiple dwelling house where security of residential environment such as urban renewal policy is poor. Third, the Enforcement Decree of the Building Act shall be revised to make the crime prevention environment design of flat or multiple dwelling house obligatory, and the criteria of flat or multiple dwelling house crime prevention plan should be reflected in the notice of crime prevention building standard.

• Nutrition Research and Practice
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• v.16 no.2
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• pp.233-247
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• 2022

BACKGROUND/OBJECTIVES: The objective of this study was to describe the development process of the Korean Healthy Eating Index (KHEI) based on the Korea National Health and Nutrition Examination Survey (KNHANES). SUBJECTS/METHODS: The components of KHEI were selected based on Dietary Guidelines for Koreans, domestic and overseas dietary quality indices, and results of the analysis of association with chronic diseases. The standards for scoring of KHEI were selected based on the 2015 Dietary Reference Intakes for Koreans (KDRI). The KHEI scores of Korean adults were calculated using a 1-day 24-h recall data in the 2013-2015 KNHANES. RESULTS: The KHEI included eight adequacy components evaluating the proper intake of recommended foods such as fruit, vegetable, and milk and three moderation components evaluating the consumption of food that limit intake such as sodium and saturated fatty acid. In addition, three balance components assessing the balance of energy intake were included. The KHEI score was defined to range from the minimum of 0 point to the maximum of 100 points. Among Korean adults, the total KHEI score was 63.2 out of 100. Gender and age differences were found in the average of total KHEI scores. Women showed higher score than men (61.7 in men and 64.7 in women, respectively). By age group, 20s and 30s showed the lowest scores with 57.4 and 61.1 respectively, and the scores increased with age by peaking at 67.8 in ages 60-69 and slowed down again in ages 70 or over. CONCLUSIONS: The KHEI can be useful for establishing and assessing national nutritional policies and in epidemiological studies to assess the relationship between overall dietary quality and chronic diseases. KHEI will need to be continuously updated to reflect changes in dietary guidelines and the KDRI.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.39-52
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• 2021

Purpose: Recently, due to increasing usage of high-tech equipment for facility inspection, the need of verifying high-tech equipment is being emphasized. Therefore, the purpose of this paper is to develop performance evaluation methodology of tunnel scanners that inspect tunnel facilities. Method: This paper describes literature reviews regarding the performance evaluation methodology of high-tech based equipment for facility inspection. Based on these investigations and expert advisory meetings, this paper suggests a performance evaluation methodology of tunnel scanner. Result: First evaluation indicator states minimum performance standards of tunnel scanners. Second evaluation indicator is related to tunnel scanner quality. Conclusion: The performance evaluation methodology can provide reliable equipment performance catalogues, helping users to make a proper selection of equipment. Also, developers of equipment can get authorized verification of performances, preventing poor maintenance of facilities.