• Proceedings of the KWS Conference
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• 1995.10a
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• pp.3-20
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• 1995

Development of Real-Time Quality Evaluation of Friction Welding by Acousitc Emission : Report 1 ABSTRACT : According as the friction welding has been increasingly applied in manufacturing various machine components because of its significant economic and technical advantages, one of the important concerns is the reliable quality monitoring method for a good weld quality with both joint strength and toughness in the process of its production. However no reliable nondestructive test method is available at present to determine the weld quality particularly in process of production. So this paper presents an experimental examination and quantitative analysis for the real-time evaluation of friction weld quality by acoustic emission, as a new approach which attempts finally to develop an on-line quality monitoring system design for friction welds using AE techniques. As one of the important results, it was confirmed, through this study, that AE techniques can be reliably applied to evaluating the friction weld qualify with 100% joint strength, as the cumulative AE counts occurring during welding period were quantitatively correlated with reliability at 95% confidence level to the joint strength of welds. Real-Time Evaluation of Automatic Production Quality Control for Friction Welding Machine : Report 2 Abstract : Both in-process quality control and high reliability of the weld is one of the major concerns in applying friction welding to the economical and qualified mass-production. No reliable nondestructive monitoring method is available at present to determine the real-time evaluation of automatic production quality control for friction welding machine. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the initial cumulative counts of acoustic emission(AE) occurring during plastic deformation period of the welding and the tensile strength of the welded joints as well as the various welding variables, as a new approach which attempts finally to develop an on-line (or real-time) quality monitoring system and a program for the process of real-time friction welding quality evaluation by initial AE cumulative counts. As one of the important results, it was well confirmed that the initial AE cumulative counts were quantitatively and cubically correlated with reliability of 95% confidence level to the joint strength of the welds, bar-to-bar (SCM4 to SUM31, SCM4 to SUM24L) and that an AE technique using initial AE counts can be reliably applied to real-time strength evaluation of the welded joints, and that such a program of the system was well developed resulting in practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro-structural defects.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.123-131
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• 2015

The purpose of this study was to find out the reason why the integration policy of local government in 2010~2014 has failed in the light of multi-dimensional model including normative, structural, constituentive, and technical dimension. Central government pushed integration policy of local government focused on increasing economic efficiency based on the theory of economy of scale on 16 regions and 36 local governments. Only one region(Cheong-Ju and Cheong-Won), however, completed integration procedure in 2014. Although most regions don't have common value on integration, and cultural, political ties in normative and structural dimension, central government pushed the integration policy. Futhermore central government failed to coordinate various interests of the participants and design incentive system including demands of local residents in constituentive and technical dimension. Based on this study central government should consider these policy implications when it propel the integration policy of local government in the future.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.2
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• pp.32-45
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• 2000

This paper presents the analytic derivation of the SINR, when a linear array antenna is accommodated into the cellular CDMA basestation receiver, in relation to the two major performance effecting factors in beamforming(BF) applications, i. e., the direction selectivity, which refers to the narrowness of the mainbeam width, and the direction-of-arrival(DOA) estimation accuracy. The analytically derived results are compared with the operation simulation of the receiver realized with the several BF algorithms and their agreements are confirmed, consequently verifying the correctness of the analysis and the operation simulation. In order to investigate separately the effects of the errors occurring in the direction estimation and in the interference suppression, which are the two major functional components of general BF algorithms, both the algorithms of steering BF and the minimum- variance- distortionless-response(MVDR) BF are applied to the analysis. A signal model to reflect the spatially scattering phenomenon of the RF waves entering into the .:nay antenna, which directly affects on the accuracy of the BF algorithm's direction estimation, is also suggested in this paper and applied to the analysis and the operation simulation. It is confirmed from the results that the enhancement of the direction selectivity of the away antenna is not desirable in view of both the implementation economy and the BF algorithm's robustness to the erroneous factors. Such a trade-off characteristics is significant in the sense that it can be capitalized to obtain an economic means of BF implementation that does not severely deteriorate its performance while ensuring the robustness to the erroneous effects, consequently manifesting the significance of the analysis results of this paper that can be used as a design reference in developing BF algorithms to the cellular CDMA system.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.73-79
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• 2020

With the recent strengthening of local autonomy and the recognition of the culture and tourism industry as a driving force for the fourth industrial revolution, the importance of research on the revitalization of the local culture and tourism industry is further emphasized. Thus, in this paper, the concept and type of local culture and tourism products were summarized and the research direction was presented through this. As a research method, the internal and external factors of the culture and tourism industry in Korea were used as the SWOT analysis method. In the text, three representative sites were selected and analyzed for the development of local cultural and tourism products, and Seoul, Jeju Island, and Gyeongju all found that they lacked local cultural and tourism products. It also found another value through its role of cultural development as well as the economic aspect of the development of cultural tourism products. In order to revitalize the local culture and tourism industry, which has become more important, the government proposed measures to promote differentiated creative products, efficient marketing, and legal security in various ways. In order for this study to be better data for researchers in the culture and tourism industry and related industries, research should be conducted with detailed surveys that could not be conducted due to various restrictions in the future.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.1-9
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• 2010

Objectives : The purposes of this study were to evaluate exhaust ventilation systems(EVSs) and to suggest problems and improvements. Methods : For 50 small and medium-sized enterprises, we carried out evaluation of EVSs. We evaluated hoods with smoke tester and measurement of capture velocity. In addition, we used several indicators for performance evaluation designed in this study. Results : 1. Based on the smoke flow pattern and the criteria of occupational health and safety act, 67.8% of hoods were rated 'good' level at smoke test whereas 26.3% were rated 'good' level at measurement of capture velocity. 2. 29.3% of hoods, of which ratio of measured actual air flow at hood(Qah) to required ideal exhaust air flow at hood(Qih) was 1 or more, were rated 'good' level. 3. The % of EVS, of which ratio of measured actual air flow at stack(Qast) to total required ideal exhaust air flow at hood(Qith) was 1 or more, was 29.0%. 4. For the ratio of measured Qast to existing air flow at fan(Qfan), only 5% of EVSs were 1 or more and 26.0% were 0.8 or more but less than 1.0. 5. For the ratio of measured Qast to total measured actual exhaust air flow at hood(Qath), 74.0% were 0.8 or more but less than 1.0. 6. The percentage of EVS, of which ratio of total measured Qath to existing Qfan was 0.8 or more, was 19.0%. 7. The percentage of EVS, of which ratio of total measured Qath to total required ideal exhaust Qith was 1 or more, was 26.0%. 8. For the comprehensive evaluation indicators designed in this study, 29.0% were 0.8 or more. Conclusions : We found that few exhaust local ventilations at small and medium-sized enterprises were rated 'good' level and that most exhaust local ventilations had 'poor' design and installation. Therefore, relevant professional manpower and enterprises have to construct exhaust local ventilation where it is needed, and technical guidance and economic support are needed to improve 'poor' exhaust local ventilation after self-evaluation.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.19-24
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• 2020

WHO declared a global pandemic on March 11th for Corona 19. However, there is a situation where you have to go to building for face-to-face education or seminars for economic and social activities. The first check method of COVID-19 infection is to measure body temperature, so the primary entrance and exit is blocked for near-field body temperature measurement. However, since it is troublesome to check directly, thermal camera is installed at the entrance of the building, and body temperature is measured indirectly using the infrared camera to control access. In case of middle and high schools, universities, and lifelong education center, we need a system that is possible to interoperate with attendance checks and automatically recognizes whether to wear masks and can authenticate students. We proposed the system that is to confirm whether to wear a mask with a camera that is embedded in a smart mirror, and that authenticates the user through voice recognition of the user who wants to enter the building by using voice recognition technology and determines whether to enter them or not. The proposed system can check attendance if it is linked with near-field temperature measurement and attendance check APP of student's smart phone.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.41-49
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• 2020

This study is a descriptive research study for the elderly who participated in the community's fair to identify the factors of the convergent impact of perceived health conditions, health promotion activities and dementia anxiety on the quality of health-related life. The research subjects were surveyed on 435 senior citizens aged 65 or older among the participants in the 2019 Regional Exposition, and analyzed using statistics, ANOVA, Pearson's correlation and multiple regression analysis using the SPSS 21.0 program. According to the study, the quality of life related to health affects 53.0% of the convergence factors such as perceived health conditions, health promotion activities, monthly income, and economic conditions. Therefore, various community events or programs that can lead to the reduction of dementia anxiety and the improvement of health promotion activities will have to be developed to motivate or make promotional efforts for senior citizens to participate in community events or programs, which will enable senior citizens to build social networks through the participation of various programs in the community, thereby improving health promotion activities and reducing dementia anxiety, which will improve the quality of life for senior citizens.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.515-524
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• 2001

Two experiments using growing and finishing pigs (Landrace$\times$Duroc$\times$Yorkshire) were conducted to determine the effects of different levels of vitamins and trace minerals (VTM) on growth performance, nutrient digestibility, carcass characteristics and meat quality of growing-finishing pigs, and to evaluate the suitability of vitamin-mineral levels commonly used in the swine industry in Korea. A total of 120 three crossbred (Landrace$\times$Duroc$\times$Yorkshire) growing (Experiment I: 20.90 0.44 kg average initial body weight) and finishing (Experiment II: 53.55 0.97 kg average initial body weight) were used in 6 and 9 weeks feeding trials, respectively. Pigs were allotted on the basis of sex and weight to 5 treatments with 6 replications per treatment with 4 pigs per pen in a completely randomized block design. Treatments were: 1) control, 2) fat soluble vitamin 200% vs. control, 3) water soluble vitamin 200% vs. control, 4) trace mineral 50% vs. control, 5) trace mineral 200% vs. control. In experiment I, during the overall experimental period (0 to 6 weeks, 21 to 54 kg body weight), ADG of the 200% trace mineral supplemented group was significantly higher than that of the 50% trace mineral supplemented group. There were no significant differences among other the treatments. Digestibility of crude protein was lowest in mineral 50% supplemented group (p<0.05). Calcium digestibility was significantly higher in the 200% fat soluble vitamin supplemented group than in the other treatments (p<0.05). In experiment II, during the overall experimental period (0 to 9 weeks, 54 to 106 kg body weight), growth performance was not significantly affected by dietary vitamin and trace mineral levels. However, increasing level of water soluble vitamins at the level of 200% compared to control had a tendency to improve the overall growth performance. Overall carcass characteristics except for carcass length did not differ among pigs fed the dietary treatments. Loin eye area, pH, drip loss and shear force of meat were not affected by dietary vitamin and trace mineral levels. There was a trend for less fat content (%) in pork when the level of vitamin and trace mineral was increased, but the difference was not significant. Flavor score was the lowest in control and highest in the 200% fat soluble vitamin supplemented group (p<0.05). Juiciness of muscle was lower in the 200% fat soluble vitamin supplemented group than other dietary treatments, except for trace mineral 50% supplemented group (p<0.05). Based on these results, it is suggested that "typical" commercial levels of vitamin and trace minerals used by feed companies in Korea are sufficient to meet requirement for the maximum growth of growing-finishing pigs. Our results suggests that a reduction in trace mineral levels in commercial diets could be considered to reduce feed cost and nutrient excretion with economic and environmental benefits.

• Spatial Information Research
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• v.21 no.3
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• pp.21-30
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• 2013

Recently, interest of submarine mineral resources has been increasing from the depletion of land resources around the world and many countries are involving in submarine mineral resource exploration work. South Korea is also in progress of mineral exploration and relevant study to ensure the submarine mineral resources from around the Korean Peninsula. As a result, the submarine mineral resource exploration data have been increasing annually. A database and 2D GIS-based system have been constructed for the management of the data. However, submarine mineral resource exploration data is explored and created on the sea-bed. Consequently, the visual confirmation of the water levels and marine landform is important for high dimension analysis. Therefore, the major aims of this study are to collect marine landform data from around the Korean Peninsula and to develop 3 dimension GIS based system that is linked to the submarine mineral resource exploration data. In detail, marine landform data were acquired for the Korean Peninsula and they were interpolated into raster file format. The raster file was then processed to be easily used and was entered into an Oracle database. Based on this database, 3D expression and overlap function between marine landform data and submarine mineral resource exploration data were designed using ArcScene offered by the ESRI. After design, 3D GIS based expression system was developed. Confirmations of locations and changes in the submarine mineral resource exploration data based on 3D GIS are enabled to support the efficient application of the proposed system. It is expected that this system will be highly useful for estimating the reserves of mineral resources and for providing valuable information for economic evaluations.

• The Journal of Bigdata
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• v.4 no.2
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• pp.159-173
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• 2019

Last-Mile delivery optimization plays a key role in the urban supply chain operation, which is the most expensive and time-consuming and most complicated part of the whole delivery process. The urban consolidation center (UCC) is regarded as a significant asset for supporting customer demand in the last-mile delivery service. It is the key benefit of UCC to improve the load balance of vehicles and to reduce the total traveling distance by finding the better route with the well-organized multi-leg vehicle journey in the urban area. This paper presents the model using multiple scenario analysis integrated with mathematical optimization techniques using Geographic Information System (GIS). The model aims to find the best solution for the distribution network consisted of DC and UCC, which is applied to the case of Ulaanbaatar Mongolia. The proposed methodology integrates two sub-models, location-allocation model and vehicle routing problem. The multiple scenarios devised by selecting locations of UCC are compared considering the general performance and delivery patterns together. It has been adopted to make better decisions the quantitative metrics such as the economic value of capital cost, operating cost, and balance of using available resources. The result of this research may help the manager or public authorities who should design the distribution network for the last mile delivery service optimization using UCC within the urban area.