• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.599-608
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• 2012

A numerical analysis has been performed through implicit dynamic finite element analysis using the commercial package, ABAQUS in order to investigate effect of laser peening on welding residual stress mitigation of dissimilar metal welds in a safety injection nozzle of integral reactor. The implicit dynamic finite element analysis are compared with the previous experimental results. By comparison, it is identified that the implicit dynamic finite element analysis is valid for residual stress mitigation via laser peening. Implicit static finite element residual stress analysis has been performed for the dissimilar metal welds subject to inner repair welding. The analysis results represent that both axial and hoop residual stresses are tensile on inner surface of safety injection nozzle due to inner repair welding. Also Parametric study has performed to investigate effect of laser peening variables such as maximum impact pressure, duration time of pressure, spot diameter and peening direction on the welding residual stress mitigation. As a result, it is found that laser peening has the preventive maintenance effect to mitigate mainly residual stresses of region near inner surface.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.609-618
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• 2021

The spread and damage of COVID-19 are putting significant pressure on the world, including Korea. Most countries place restrictions on movement and gathering to minimize contact between citizens and these policies have brought new changes to social patterns. This study generated traffic volume data on the scale of a road network using taxi movement data collected in the early stages of the COVID-19 third pandemic to analyze the impact of COVID-19 on movement patterns. After that, correlation analysis was performed with the data of confirmed cases in Daegu Metropolitan City and Local Moran's I was applied to analyze the effect of spatial characteristics. As a result, in terms of the overall road network, the number of confirmed cases showed a negative correlation with taxi driving and at least -0.615. It was confirmed that citizens' movement anxiety was reflected as the number of confirmed cases increased. The commercial and industrial areas in the center of the city confirmed the cold spot with a negative correlation and low-low local Mona's I. However, the road network around medical institutions such as hospitals and spaces with spatial characteristics such as residential complexes was high-high. In the future, this analysis could be used for preventive measures for policymakers due to COVID-19.

• Journal of the Economic Geographical Society of Korea
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• v.26 no.2
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• pp.123-136
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• 2023

Upon examining land prices in the eastern district of Gyeongseong, it was observed that there were variations in land prices between the northern and southern areas, with the central part being densely populated with modern facilities such as hospitals, schools, and research institutions. As a result, the eastern district of Gyeongseong was further divided into specific sub-areas, namely the northeastern and southeastern, for a more detailed analysis of the land market in each area. In the northeastern area, factors such as distance from the central area and proximity to planned roads were found to have an impact on land prices. On the other hand, in the southeastern area, the distance between the main road, whice were IHyun Road and Jongro, was identified as a significant influencer of land prices. Therefore, the northeastern area exhibited characteristics of a hinterland, influenced by the concentration of major facilities in the central area, while the southeastern area had a strong commercial orientation, largely shaped by the influence of Jongro as a bustling commercial district. This study is significant in that it sheds light on certain aspects of the modern land market by demonstrating that factors such as accessibility to roads and anchor facilities, as well as the segmentation of the land market, were also influential in the land market a century ago.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.275-282
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• 2015

Recently, Vecna BEAR type robot to save injured individuals from inaccessible areas has been developed to minimize the loss of life. Because this robot is driven on rough terrain, there is a risk of rollover and vibration, which could impact the injured. In order to guarantee its stability, an algorithm is required that can estimate the speed limits for various environments in real time. Therefore, a dynamic model for real-time analysis is needed for this algorithm. Because the tracks used as the driving component of Vecna BEAR type robot consist of many parts, it is impossible to analyze the multibody tracks in real time. Thus, a lumped track model that satisfies the requirements of a short computation time and adequate accuracy is required. This study performed lumped track modeling, and the traction force was verified using RecurDyn, which is a dynamic commercial program.

• Knowledge Management Research
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• v.21 no.1
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• pp.175-195
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• 2020

The development of platform service based on the information and communication technology has revolutionized patterns of commercial transactions, driving the growth of global economy. Furthermore, the radical advancement of artificial intelligence(AI) presents the huge potential to innovate almost all the industrial and economic activities. Given these technological developments, the goal of this paper is to investigate AI's impact on the platform service innovation as well as its influence on the business performance. For the goal, this paper presents the review of the types of service innovation, the nature of platform services, and technological characteristics of leading AI technologies, such as chatbot and recommendation system. As an empirical study, this paper performs a multiple case study of Kakao Group which is the leading mobile platform service with the most advanced AI in Korea. To understand the role and effect of AI on Kakao platform service, this study investigated three cases, including chatbot agent of Kakao Bank, Smart Call service of Kakao Taxi, and music recommendation system of Kakao Mellon. The analysis results of the case study show that AI initiated innovations in platform service concepts, service delivery, and customer interface, all of which lead to a significant decrease in the transaction costs and the personalization of services. Finally, for the successful development of AI, this research emphasizes the significance of the accumulation of customer and operational data, the AI human capital, and the design of R&D organization.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3111-3111
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• 2001

The implementation of NIR and chemometrics in the Pharmaceutical industries is still in strong progress, both regarding qualitative and quantitative applications and beneficial results are seen. Looking at the development so far, NIR will change the pharmaceutical industry even more in the future. This presentation will address the experiences and progress achieved regarding the application and implementation of quantitative methods for determination of content uniformity and assay of tablets with less than 10% w/w of active, using Near Infrared transmittance spectroscopy in combination with PLS. Also qualitative methods for identification of the same tablets by Near Infrared reflectance spectroscopy will be discussed. Four commercial tablet strengths are formulated and produced from two different compositions by direct compression. Three different strengths are dose proportional, i.e. fixed concentration by varying in size. The aim was to replace the conventional primary methods for analysing content uniformity, assay and identification by NIR. Studies were performed on comparing transmittance versus reflectance spectroscopy for both applications on the dose proportional tablets. The model for determination of content uniformity and assay was developed to cover both coated and uncoated tablets, whereas the qualitative model was developed to identify coated tablets only. The impact of the tablet formulation, tablet size and coating, resulted in individual models far each composition The best calibration was achieved using diffuse reflectance for the identification purposes and diffuse transmittance for the quantitative determination of the active content within the tablets. As NIR in combination with other techniques opens up the possibility of total quality management within the production, the transfer of the above-mentioned models from a laboratory based approach to an at-line approach at H.Lundbeck will be addressed too.

• Atmosphere
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• v.25 no.2
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• pp.309-322
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• 2015

The objective of this study is to evaluate the impact of the high resolution topographies and landuses data on simulated meteorological variables (wind speed at 10 m, temperature at 2 m and relative humidity at 2 m) in WRF. We compare the results with WRF simulation using each resolution of the topographies and landuses, and with 37 AWS observation data on the Seoul metropolitan regions. According to results of using high-resolution topography, WRF model gives better topographical expression over domain. And we can separate more detail (Low intensity residential, high intensity residential, industrial or commercial) using high resolution landuses data. The result shows that simulated temperature and wind speed are generally higher than AWS observation data. However, simulation trend with temperature, wind speed, and relative humidity are similar to observation data. The reason for that is that the high precipitation event occurred in CASE 1 and 2. Temperature have correlation of 0.43~0.47 and standard deviation of $2.12{\sim}2.28^{\circ}C$ in CASE 1, while correlation of more than 0.8 and standard deviation of $3.05{\sim}3.18m\;s^{-1}$ in CASE 2. In case of wind speed, correlation have lower than 0.5 and Standard Deviation of $1.88{\sim}2.34m\;s^{-1}$ in CASE 1 and 2. In statistical analysis shows that using highest resolution (U01) results are more close to the AWS observation data. It can be concluded that the topographies and landuses are important factor that affect model simulation. However, the tendency to always use high resolution topographies and landuses data appears to be unjustified, and optimal solution depends on the combination of scale effect and mechanisms of dynamic models.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.763-778
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• 2019

Abrasive waterjet cutting technology has been used for rock excavation of tunnels and underground structures due to various advantages. In order to cut rocks by using the abrasive waterjet system, abrasive is essential to enhance impact energies for fracturing the target rock. Since garnet abrasives are not produced in Korea, alternative abrasives, instead of garnets, are needed to achieve the economical waterjet cutting. This study is to analyze cutting performance for rocks with sandy particles as alternative abrasive. Cutting tests were carried out on granite specimens at the constant waterjet energy (e.g., water pressure or water flow rate). The five kinds of sands, sampled by construction fields and natural sites, were prepared to perform the experimental tests. When sea sand was used as an alternative abrasive, cutting performance was secured to be 60~70% compared to the commercial garnet abrasive. Thus, it is expected that sand abrasives can be applied on the waterjet cutting process for the economical excavation construction.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.611-633
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• 2017

This research was designed to verify the causal relationships between organization managers' unmet expectations and job burnout and the mediating effects of overcommitment based on the effort-rewards imbalance theory. It was also intended to evaluate the moderating effect of LMXSC on the relationship between overcommitment and job burnout. 172 branch managers working at commercial bank were selected as the target research group. This study was validated by The SPSS 24.0, the reliability was justified through the factor analysis, and the casual relationship was confirmed through the three-step regression. As a result, unmet expectations had a strong positive correlation with job burnout and overcommitment. Overcommitment had a strong positive correlation with the mediating effect between unmet expectations and job burnout. Moderating effects of LMXSC were not significant. This study showed the practical implication between unmet expectations, overcommitment, and job burnout. Additionally it exhibited the job design and management practice in manager groups where the importance of their role has been expanded. Lastly, we found the interdisciplinary implication from making an effort to elaborate the antecedent of variables.

• Journal of Arbitration Studies
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• v.18 no.2
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• pp.3-31
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• 2008

At its thirty-ninth session(New York, 19 June - 7 July 2006), United Nations Commission on International Trade Law(hereinafter referred to as the Commission) agreed to give priority to the topic of revising the UNCITRAL Arbitration Rules. From the forty-fifth through the forty-seventh session, the Working Group checked various issues based on the draft revised version of the UNCITRAL Arbitration Rules prepared by the Secretariat. At its forty-eighth session, the Working Group is going to finish its first reading of articles 38 to 41 of the draft revised version of the UNCITRAL Arbitration Rules, and to commence its second reading of the draft revised version of UNCITRAL Arbitration Rules. Korea is keen on enticing foreign direct investment into its territory. From the 1960s, Korea has concluded more than 80 BITs. Korea is making efforts to conclude FTAs with its trading partners. As of January, 2008, 3 FTAs have taken into effect with respect to Korea. According to provisions on dispute settlement found in such BITs and FTAs involving Korea, the Rules can be chosen for Investor-State Arbitration. Furthermore, the Rules is followed by the arbitration rules for domestic and international arbitrations administered by the Korean Commercial Arbitration Board. If the Commission adopts the revised version of UNCITRAL Arbitration Rules, the Rules will be able to give impact on the arbitration law and practice around the world of arbitration. That is the reason why we should keep attention to the development of the deliberations of the Working Group.