• Knowledge Management Research
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• v.5 no.1
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• pp.39-56
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• 2004

Mergers and Acquisitions(M&A) have long played an important role in the growth of firm. M&A has been considered a effective strategy for Korean government to restructure industry. Previous studies provided mixed results on the synergy effect of M&A This study provides investigation on 39 mergers occurred over the sample period from 2000 to 2001. In this study, event study methodology arc used to calculate abnormal return(AR) and cumulative abnormal return(CAR) based on mean-adjusted model. The testing period of this study from date -30 through date +30, where date zero is the date of the first public announcement of the merger. The empirical results in this study can be summarized as follows. First, the return rates of KOSDAQ registered firms with M&A appears higher than that of KSE listed firms. This means that public announcement of M&A is more influential on stock price for KOSDAQ registered firms than KSE listed firms. Second, The difference between actual merging price and fair value is significant in KSE listed firms and KOSDAQ registered firms. This means that the investors take M&A of KOSDAQ registered firms as a good news. Third, the impact on the market prices of merging firms take place after the first public announcement of the merger in KSE registered firms. But the impact on the market prices take place not only merging firms but also merged firms in KOSDAQ registered firms. This result shows that the investors recognize a M&A is a strategy of technology transfer in small & venture business.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.47-54
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• 2008

In this paper, we studied how and why did abnormal IMC growth at component affect on board level mechanical reliability. First, interfacial reactions between Sn2.5Ag0.5Cu solder and electrolytic Ni/Au UBM of component side were investigated with reflow times and thermal aging time. Also, to compare mechanical reliability of component level, shear energy was evaluated using the ball shear test conducted with variation of shear tip speed. Finally, to evaluate mechanical reliability of board level, we surface-mounted component fabricated with each condition on PCB side. After conducting of 3 point bending test and impact test, we confirmed solder joint crack mode using cross-sectioning and dye & pry penetration method.

• Knowledge Management Research
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• v.13 no.5
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• pp.139-160
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• 2012

Win-win growth between large companies and small and medium enterprises (SMEs) become a critical encomic and social issue in Korea. Korea government has been attempted to establish strong policy to build right win-win relationship between large companies and SMEs. Along with this strong drive from Korea government, a variety of strategies that enhance win-win relationships between large companies and SMEs have been adopted. Win-win growth policy is expected to provide positive impact on sustainable competitive advantage of firms. Therefore, many studies have focused on the win-win growth policy success factors, type of the policy, and the results of the policy. Although there is much literature on the win-win growth policy, the effects of win-win policy on firm value is not well understood. We addressed this issue by exploring how win-win growth policy influences a firm's market value using event study methodology. We evaluated the cumulative abnormal returns for win-win growth policy announced by Korean large firms from 2004 to 2012. The results of this study insisted that the announcements of win-win growth policy show negative impact on firm's market value, which is not consistent with previous studies. The findings of this study offer insights that may help government policy makers and managers to revise their policy for better outcomes of their win-win growth policy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.197-204
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• 2021

If a failure or an abnormal maneuver occurs during the flight test of a missile, the missile is deliberately self-destructed so as not to continue the flight. At this time, debris are produced and it is important to estimate the impact area in real-time whether it is out of the safety area. In this paper, we propose a method to estimate the debris dispersion area and falling time in real-time using a Fully-Connected Neural Network (FCNN). We applied the Unscented Transform (UT) to generate a large amount of training data. UT parameters were selected by comparing with Monte-Carlo (MC) simulation to secure reliability. Also, we analyzed the performance of the proposed method by comparing the estimation result of MC.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10067-10070
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• 2015

Background: Unopposed estrogen has a central role in development of endometrial benign, premalignant and malignant lesions. The aim of this study was to evaluate the anti-estrogenic effect of metformin on endometrial histology in comparison with progesterone. Materials and Methods: A total of 43 patients who were referred to our center for abnormal uterine bleeding and had a histologic diagnosis were disordered proliferative endometrium or simple endometrial hyperplasia were included and randomly distributed in two groups treated with metformin (500mg Bid) or megestrol (40mg daily), respectively, for three months. After this period the patients were evaluated by another endometrial biopsy to assess the impact of the two drugs in restoring normal endometrial histology. Results: Our findings revealed that metformin could induce endometrial atrophy in 21 out of 22 patients (95.5%) while this positive response was achieved in only 13 out of 21 patients (61.9%) in the megstrol group. In addition two low grade endometrial carcinomas in the metformin group responded very well. Conclusions: We conclude that metformin could be used as an effective antiestrogenic agent in control of abnormal endometrial proliferative disorders.

• Journal of Internet of Things and Convergence
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• v.5 no.2
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• pp.95-101
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• 2019

Entering the era of the 4^th Industrial Revolution and the Internet of Things, various services are growing rapidly, and various researches are actively underway. Among them, research on abnormal behaviors on various devices that are being used in the IoT is being conducted. In a hyper-connected society, the damage caused by one wrong device can have a serious impact on the various connected systems. In this paper, We propose a technique to cope with the problem that the threats caused by various abnormal behaviors such as anti-debugging scheme, anomalous process detection method and back door detection method on how to increase the safety of the device and how to use the device and service safely in such IoT environment.

• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.10-18
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• 2013

Oil spills have occurred throughout the years of industrialization and represent a global challenge as they affect vast areas of the ocean. The toxicity of crude oil to aquatic organisms has been extensively investigated, but the potential impacts of crude oil on vertebrate development remain largely unknown. Here, we investigated the effects of dispersants used in treating a recent oil spill, as well as that of crude oil, on vertebrates by using the zebrafish (Danio rerio) model species, which has been widely used in empirical studies of both early embryonic development and adult physiology. Chronic exposure to crude oil resulted in marked developmental abnormalities, including pericardial edema, abnormal trunk vessel development, retardation of axonal branching, and abnormal jaw development. Embryonic development was affected more severely by exposure to the oil-dispersant combination than to the oil alone. Thus, the zebrafish in vivo model system suggests that dispersant treatment can have detrimental developmental effects on vertebrates and its potential impact on marine life, as well as humans, should be carefully considered in clean-up efforts at the site of an oil spill.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.1
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• pp.14-17
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• 2016

Hoarseness is a postoperative complication of thyroidectomy, mostly due to damage to the recurrent laryngeal nerve (RLN). Hoarseness may also be brought about via vocal cord dysfunction (VCD) due to injury of the vocal cords from manipulations during anesthesia, as well as from psychogenic disorders and respiratory and upper-GI related infections. The clinician or surgeon should 1) document assessment of the patient's voice once a decision has been made to proceed with thyroid surgery ; 2) examine vocal fold mobility, or refer the patient to a clinician who can examine vocal fold mobility 3) examine vocal fold mobility, or refer the patient to a clinician who can examine vocal fold mobility, once a decision has been made to proceed with thyroid surgery 4) educate the patient about the potential impact of thyroid surgery on voice once a decision has been made to proceed with thyroid surgery ; 5) inform the anesthesiologist of the results of abnormal preoperative laryngeal assessment in patients who have had laryngoscopy prior to thyroid surgery ; 6) take steps to preserve the external branch of the surperior laryngeal nerve(s) when performing thyroid surgery ; 7) document whether there has been a change in voice between 2 weeks and 2 months following thyroid surgery ; 8) examine vocal fold mobility or refer the patient for examination of vocal fold mobility in patients with a change in voice following thyroid surgery ; 9) refer a patient to an otolaryngologist when abnormal vocal fold mobility is identified after thyroid surgery ; 10) counsel patients with voice change or abnormal vocal fold mobility after thyroid surgery on options for voice rehabilitation.

• The Korean Journal of Financial Management
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• v.20 no.1
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• pp.61-92
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• 2003

As an extension of previous researches with the conclusion that the announcement of adopting stock options generates positive abnormal returns, this paper examined whether the abnormal return changes over time or varies depending on the number of stock options granted. Empirical analysis was made to find whether the announcement of stock option awards has the same response in the stock market from the early days when stock option plans had been introduced in the Korean stock market till today when it was widespread. Results indicate that the announcement effect had been on a gradual decline since 2000. In addition, it is found that if a company announces stock option awards several times, the abnormal return gradually declines in proportion of the number of stock options granted. This implies that as the stock option awards become widespread, the positive effect that the announcement of adopting stock options generates as news has been on a relatively steady decrease. In short, it leads to a conclusion that the more companies grant stock options, and the more stock options a company announces, the less impact it has on the increase in the firm's value.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4209-4212
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• 2016

Purpose: To study clinical factors related to adequacy of transformation zone (TZ) components in cervical smears. Materials and Methods: Medical and Papanicolaou (Pap) smear reports from Thammasat University Hospital, Thailand during January to December 2015 were collected. Demographic data was reviewed by attending physicians and impact of clinical factors onTZ adequacy was primary outcome. A total of 3,251 smears were reviewed. Finally, 2,098 smears met The inclusion criteria and enrolled into this study. Results: Average age and bodyweight of participants in this study were 43.0 years and 60.0 kg, respectively. Ninety seven percent of smears were classified as satisfactory for evaluation according to the Bethesda system 2001. Adequacy (group A) and inadequacy (group B) of TZ were equal in percentage (50.9/46.0). Prevalence of abnormal cervical cytology was 4.4%. Percentages of abnormal Pap smears in group A and B were 7.3 and 1.4, respectively (p<0.001). Factors associated with increased adequacy of TZ were old-age (${\geq}50yr$), nulliparity, within 3-months postpartum, history of TZ inadequacy and abnormal smears. Sexually transmitted disease (STD), hormonal usage, previous cryotherapy and smears collected by staff were associated with inadequacy of TZ. Conclusions: Collection of cervical specimens should be carefully performed. STD history, hormonal usage and previous cryotherapy are risk factors for TZ inadequate specimens.