• Journal of the Korea Convergence Society
• /
• v.9 no.10
• /
• pp.257-263
• /
• 2018

The purpose of this study is to develop an automatic inspection system for a part of the differential drive gear into the transmission. This technology will make using the microvision automatic test equipment and automatic test equipment microlaser. This is that the operator intends to make the defect rate 0 in the inspection stage of the product which has been carelessly processed. The equipment developed in this research project will be applied to many areas. Packaging companies, nut bolt processing company, precisely supplier for printing on top of the semiconductor, SMT, etc. The company wants to sell the vision inspection equipment for various applications. If the defective rate of 0 is achieved through this research project, it is also possible to secure a stable supply from the parent company, and to lay the foundations for exporting based on product reliability. When the automatic inspection system is applied to domestic automobile parts processing companies, the reliability of automobiles in Korea will be greatly increased.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1297-1300
• /
• 2008

A conventional linear accelerator system requires a flat-topped pulse with less than ${\pm}$ 0.5% ripple to meet the beam energy spread requirements and to improve pulse efficiency of RF systems. A pulse transformer is one of main determinants on the output pulse voltage shape. The pulse transformer was investigated and analyzed with the pulse response characteristics using a simplified equivalent circuit model. The damping factor ${\sigma}$ must be >0.86 to limit the overshoot to less than 0.5% during the flat-top phase. The low leakage inductance and distributed capacitance are often limiting factors to obtain a fast rise time. These parameters are largely controlled by the physical geometry and winding configuration of the transformer. A rise time can be improved by reducing the number of turns, but it produces larger pulse droop and requires a larger core size. By tradeoffs among these parameters, the high-voltage pulse transformer with a pulse width of 10 ${\mu}s$, a rise time of 0.84 ${\mu}s$, and a pulse droop of 2.9% has been designed and fabricated to drive a klystron which has an output voltage of 284 kV, 30-MW peak and 60-kW average RF output power. This paper describes design optimization of a high-voltage pulse transformer for high-power pulsed applications. The experimental results were analyzed and compared with the design. The design and optimal tuning parameter of the system was identified using the model simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.3
• /
• pp.74-80
• /
• 2006

This paper deals with the control and fault monitoring of a DDV hydraulic actuation system. A hydraulic servo system has a nonlinear dynamics of an orifice flow through a valve spool. A full nonlinear model for a DDV actuation system is driven, and linearized to a simple model which is convenient for a control loop and fault monitor design. A top level requirement on the performance and safety for the actuation system is introduced. A control system and fault monitoring structure which can meet these requirements are discussed. A simulation package for a DDV actuation system which has a triplex redundant structure is developed.

• Journal of Digital Convergence
• /
• v.18 no.1
• /
• pp.23-33
• /
• 2020

This study discussed 'inclusive growth', which recently has gained attention as the 4th Industrial Revolution spreads, and considered innovative growth as a requirement for inclusive growth. Combining inclusiveness and innovativeness, a new concept of 'Digital New Deal' is suggested. Specifically, the new market creation strategy through digital transformation of existing industries and public sectors, and solving social problems were presented. It also analyzed problems of the past government-led top-down innovation drive and suggested the "Hybrid" approach as a new way of promoting digital New Deal. Finally, we looked at the 'job creation' effect, discussed the meaning of it in terms of inclusiveness and innovativeness, and proposed a policy alternatives to create lasting effects.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.2 s.257
• /
• pp.277-284
• /
• 2007

The steam generator in a nuclear power plant is a large heat exchanger that uses heat from a reactor to generate steam to drive the turbine generator. Rupture of a steam generator tube can result in release of fission products to environment outside. Therefore, an accurate integrity assessment of the steam generator tubes with cracks is of great importance for maintaining the safety of a nuclear power plant. The steam generator tubes are supported at regular intervals by support plates and rotations of the tubes are restrained. Although it has been reported that the limit load for a circumferential crack is significantly affected by boundary condition of the tube, existing limit load solutions do not consider the restraining effect of support plate correctly. In addition, there are no limit load solutions for circumferential cracks in U-bend region with the effect of the support plate. This paper provides detailed limit load solutions for circumferential cracks in top of tube sheet and the U-bend regions of the steam generator tube with the actual boundary conditions to simulate the restraining effect of the support plate. Such solutions are developed based on three dimensional finite element analyses. The resulting limit load solutions are given in a polynomial form, and thus can be simply used in practical integrity assessment of the steam generator tubes.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.3
• /
• pp.1-12
• /
• 2009

This study aims to analyze the existing problem of geo-spatial information maintenance and then, show maintenance strategies suitable for new integrated environments. We look for AS-IS which is provider-centered, top-down, and also drive implications from analyzing oversea best practice. For analyzing of geo-spatial maintenance pattern, we polled about 20 local governments and private enterprise to find out AS-IS of geo-spatial information and result in maintenance pattern and component. From this, we suggest 4 kinds of strategies. This study shows the strategy not only which decide the question about the problem of existing geo-spatial maintenance but which find a way of combining and utilizing all geo-spatial information which is 8 criteria basic geographical information. This is a win-win program of all organization which produce, construct, make full use of national geo-spatial information.

• Convergence Security Journal
• /
• v.18 no.4
• /
• pp.53-61
• /
• 2018

Recently 4th Industrial Revolution era has come up and autonomous vehicle gets a huge attention for its commercialization as well as development. To this end, many countries such as US, UK, Germany are looking into laws and policies related to autonomous vehicle making a new law system, laws, policies or at least modifying the existing ones. Korea is also facing commercialization and development of autonomous vehicle yet it's law system, laws and policies are far beyond comparing to those of advanced countries. This paper details current law system comparison of several countries providing differences and characteristics for the purpose of success of auto drive vehicle industry. On top of that we suggest a new law system, laws and policies and then provide directions as steps for mature implementation. In addition, we discuss how the new laws and policies can bring out successful commercialization as well as industrial success of autonomous vehicle at the points of consumers, vehicle makers, insurance companies, and government.

• Korean Journal of Metals and Materials
• /
• v.47 no.11
• /
• pp.716-721
• /
• 2009

The major drive for the application of low-temperature plasma treatment in nitrocarburizing of austenitic stainless steels lies in improved surface hardness without degraded corrosion resistance. The low-temperature plasma nitrocarburizing was performed in a gas mixture of $N_{2}$, $H_{2}$, and carbon-containing gas such as $CH_{4}$ at $450^{\circ}C$. The influence of the processing time (5~30 h) and $N_{2}$ gas composition (15~35%) on the surface properties of the nitrocarburized layer was investigated. The resultant nitrocarburized layer was a dual-layer structure, which was comprised of a N-enriched layer (${\gamma}_N$) with a high nitrogen content on top of a C-enriched layer (${\gamma}_C$) with a high carbon content, leading to a significant increase in surface hardness. The surface hardness reached up to about $1050HV_{0.01}$, which is about 4 times higher than that of the untreated sample ($250HV_{0.01}$). The thickness of the hardened layer increased with increasing treatment time and $N_{2}$ gas level in the atmosphere and reached up to about $25{\mu}m$. In addition, the corrosion resistance of the treated samples without containing $Cr_{2}N$ precipitates was enhanced than that of the untreated samples due to a high concentration of N on the surface. However, longer treatment time (25% $N_{2}$, 30 h) and higher $N_{2}$ gas composition (35% $N_{2}$, 20 h) resulted in the formation of $Cr_{2}N$ precipitates in the N-enriched layer, which caused the degradation of corrosion resistance.

• Journal of Korea Trade
• /
• v.25 no.4
• /
• pp.108-127
• /
• 2021

Purpose - On the basis of knowledge transfer theory, we empirically explored how three types of human resource (HR) innovation knowledge exchange within a Chaebol drive the global subsidiary performance of the headquarters (HQ) of a Chaebol's globally affiliated companies. Design/methodology - Using a sample of 176 Korean HQ firms of the top 53 Chaebols and 1,061 of their foreign manufacturing subsidiaries (n = 1,061), we tested the relationship between the exchange of explorative and exploitative sustainable HR innovation knowledge among HQ firms of Chaebols, their subsequent transfer of technical HR knowledge via technical schemas, and the subsequent impact on the global subsidiary performance. Findings - The Chaebols' decisions about the three strategic knowledge management options (i.e., the degree of exchange of explorative and exploitative technological HR innovation knowledge and the extent of HQ-subsidiary HR knowledge transfer) have highly significant relationships with the global subsidiary performance. The results help explains the conditions under which the explorative versus exchange of exploitative sustainable HR innovation knowledge pays off by showing the moderating role of the degree of HQ-to-subsidiary technical HR knowledge transfer, at least in the case of the Chaebol as one representative type of the emerging-market business groups. Originality/value - As the first of its kind in the field of sustainable HR innovation knowledge management at the business group level, the present study makes a clear contribution in demonstrating how the performance of Chaebols' manufacturing subsidiaries depends greatly on their strategy for management of knowledge, as reflected in the choices they make about sharing both explorative and exploitative sustainable HR innovation knowledge among HQ firms and the subsequent transfer of HQ's sustainable HR innovation knowledge to the foreign subsidiaries.

• Biomolecules & Therapeutics
• /
• v.31 no.2
• /
• pp.161-167
• /
• 2023

Despite the various medications used in clinics, the efforts to develop more effective treatments for depression continue to increase in the past decades mainly because of the treatment-resistant population, and the testing of several hypotheses- and target-based treatments. Undesirable side effects and unresponsiveness to current medications fuel the drive to solve this top global health problem. In this study, we focused on neuroinflammatory response-mediated depression which represents a cluster of depression etiology both in animal models and humans. Several meta-analyses reported that proinflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were increased in major depressive disorder patients. Inflammatory mediators implicated in depression include type-I interferon and inflammasome pathways. To elucidate the molecular mechanisms of neuroinflammatory cascades underlying the pathophysiology of depression, we introduced hycanthone, an antischistosomal drug, to check whether it can counteract depressive-like behaviors in vivo and normalize the inflammation-induced changes in vitro. Lipopolysaccharide (LPS) treatment increased proinflammatory cytokine expression in the murine microglial cells as well as the stimulation of type I interferon-related pathways that are directly or indirectly regulated by Janus kinase-signal transducer and activator of transcription (JAK-STAT) activation. Hycanthone treatment attenuated those changes possibly by inhibiting the JAK-STAT pathway and inflammasome activation. Hycanthone also ameliorated depressive-like behaviors by LPS. Taken together, we suggest that the inhibitory action of hycanthone against the interferon pathway leading to attenuation of depressive-like behaviors can be a novel therapeutic mechanism for treating depression.