• The Korean Journal of Financial Management
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• v.27 no.1
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• pp.121-156
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• 2010

Back-door-listing can be viewed both as M&A and an alternative to IPO. If IPO is an access to the capital market through regulations, back-door-listing would be the way of entering the market through trading. Back-door-listing can be a better choice considering the common wisdom that regulations hinder the functioning of free market system. One would, however, prefer IPO, for the informational asymmetry isless severe in case of IPO. This paper examines if IPO is superior to back-door-listing as to the informational efficiency. The excess buy-and-hold returns of the Kosdaq back-door-listing firms are estimated over the three-year-period since the event. They are compared against the excess buy-and-hold returns of the Kosdaq IPO firms over the same period of time. The results confirm this paper's prediction that IPO should be more information-efficient. Both IPO and back-door-listing firms start with high short-term excess returns and end up with long-term under-performance. However, back-door-listing firms show more significantly damaging long-term results. Furthermore, back-door-listing firms record poorer accounting results over the research period. These results imply that there exists fad at the time of both events and, in case of back-door-listing, this fad is reinforced by the possibility of window dressing.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.227-238
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• 2014

There is no question that railroad investment is crucial for better transport systems and the Korean government has continued to invest in railroad facilities. Nevertheless, the modal share of railroad, in particular, for freight has decreased. This is because rail freight transport can hardly meet customer needs such as just-in-time(JIT), a door-to-door service, compared to road transport, to be specific, trucking which can directly carry the freights to the final destinations. This has made the value of the railroad infrastructure less, which has been operated for the past 114 years. This study proposes a new freight movement concept called Piggy Back System. This system can carry freight trucks on the trains and deliver the freights to the final destinations. It can make a door-to-door deliver system possible for railroad transportation, which is the key factor for modal shift from road to railroad. For implementing this, this study proposes three important things: the cost-efficient reforming way of railroad yard that has been used for the past 114 years, the diagram plan of train services, and some technical reviews like clearance limits. This is the first study with practical proposals and solutions on this topic in Korea. The suggestions of this study cut down distribution costs by more than seven trillion won.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.357-360
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• 2011

In these days, the passenger vehicles usually have equipped various comfort & security systems to appeal to customers. And then, the importance of emotional quality gives added weight to the noise performance of those system devices. Door inside handle system is one of the most popular devices for passenger. This paper shows developing process about the operating sound of door inside handle. We used DFSS process to develop the door inside handle snap back sound and confirmed the improvement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3B
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• pp.199-206
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• 2006

In this paper, we analyzed the weakness of the Back-door type private network which was effective method of system security and transmission speed in the same area without firewall system, and presented the solution to improve it. To prove the effect of this solution, Windows based systems and UNIX based systems are set up in same area, data transmission was tried. According to the result, this solution can maintain the advantage of the Back-door type private network and can have the advantage of removing file server and increasing operation efficiency by reducing the number of operation.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.99-116
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• 1999

Wooden hollow core flush door is one of the main products of furniture manufacturing and woodworking industries. Warping and buckling of the door is serious problems in service. It has been reported that warping is caused by differences of physical and mechanical properties of face and back of skin panel for the door. This study focused on the prediction of warping and buckling phenomena of the flush door using numerical models. Predictions from the models were also compared with the experimental results obtained from the doors with plywood and hardboard skin panels under various environmental conditions. Three elastic constitutive models, so called elastic beam model, plate model and plate-buckling model, were employed to predict warping and buckling of the doors. It was observed that warping was more pronounced in low humidity condition than in high humidity condition. The plate model considering Poisson's effect was reliable to predict warping more closely than elastic beam model in low humidity condition. The plate-buckling model, however, was the best in the fitting of predictions with the experimental results under high humidity condition because buckling was developed in face and back of skin panel at that condition.

• Fire Science and Engineering
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• v.27 no.1
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• pp.31-38
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• 2013

The pressurized smoke control system is important for fire safety in building because it is directly concerned with egress time of people. Even though the damper plays an essential role in the pressurized smoke control system, the phenomena of backflow smoke occurs for a certain the damper position. The research for a position of damper effects on distribution of air flow at the fire door is not performed. In this study, numerical simulation using FDS 5.5 was carried out to analyze the effect of the position of damper on flow distribution at the fire door. To simulate real situation, effects of opening and closing of fire door was considered. As a result, when HRR was between 200 kW and 400 kW, in the case which the damper was on the opposite wall of the fire door, the back flow to the vestibules was large compared to the two other cases of damper position. But when HRR was above 400 kW, Effect on damper position was not occurred.

• Journal of architectural history
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• v.15 no.5
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• pp.7-18
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• 2006

A lot of relics were unearthed in the Shinchang-dong wetland site, which can help restore prehistoric life style, including construction tools such as wood doors, wood hammers, ax handgrips, sickle handgrips, wedges, awls, wood pillars and connection members, food vessels made of earth or wood and fish, shell fish, seeds and remains of weapons. In particular, a door was found in the site, which was measured at 110cm long and 37cm wide. If restored it will be 75cm wide. The door seems to date back as far as the 1st century B. C., which would be the oldest one ever discovered in Korea. This paper is intended to explore the implications of the door by investigating the environment of the Shinchang-dong wetland site bearing the relics intact, manufacturing techniques and times of manufacturing of the door as well as attributes of doors presented in the literature related to old time architecture such as Goguryeo tomb paintings and house-shaped vessels. It also intends to provide basic data for study of residential architecture in prehistoric times.

• Design & Manufacturing
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• v.17 no.2
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• pp.47-54
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• 2023

The research direction of the automobile industry worldwide is speeding up research to improve fuel efficiency through weight reduction as the weight of automobiles increases due to environmental problems, convenience demands, and safety problems. As a way to solve weight reduction, there is a method of improving mechanical properties by improving the development and manufacturing method of lightweight materials with replaceable mechanical properties. Therefore, research on the molding and processing technology of aluminum, which is a lightweight material, is being actively conducted. In this study, aluminum material was applied. By using Autoform S/W, a press forming analysis program, the blank holding force, mold die R, and bead restraint force were selected in three levels, respectively, and the results and optimization of formability and shape freezing were carried out. In this study, aluminum material was applied. By using Autoform S/W, a press molding analysis program, the blank holding force, mold die R, and bead restraint force were selected in three levels, respectively, and the results and optimization of formability and shape freezing were carried out. The optimized results were confirmed by comparative analysis of formability and Spring Back. As a result of the experiment, it was possible to confirm the result value of the Spring Back of the final product according to the tensile change of the material.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.65-71
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• 1997

Computer simulations and test trials are carried out to get the optimal conditions about the stamping die design of the tailor laser welded automotive door inner. Firstly, the stamping process including gravity deflection, bead calibration, binder wrap, forming and spring back, are analyzed by the computer simulation. The results of simulation shows good correspondance with those of test trial under the same conditions. The variables of parametric study which will be investigated in the simulation and test trials, are determined form the results of the first run. The formability under the various conditions is evaluated, which are the initial postion of blank, blank holding force, corner radius and the shape of drawbead. Finally, well controled sound product without fracture, wrinkling and excessive weldline movement is obtained.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.333-336
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• 2022

With the development of IT technology, cybercrime is becoming sophisticated and intelligent. In particular, in the case of BackDoor, which is used in the APT attack (intelligent continuous attack), it is very important to detect malicious behavior and respond to infringement because it is often unaware that it has been damaged by an attacker. This paper aims to build an EDR platform that can monitor, analyze, and respond to malicious behavior in real time by collecting, storing, analyzing, and visualizing logs in an endpoint environment in real time using open source-based analysis solutions ELK Stack and Sysmon.