• Imaging Science in Dentistry
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• v.39 no.1
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• pp.27-33
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• 2009

Purpose: The purpose of this study was to evaluate the clinical usefulness of the recently developed multi-detector computed tomography and cone beam computed tomography in pre-operative implant evaluation, by comparing them with the single detector computed tomography, already confirmed for accuracy in this area. Materials and Methods: Five partially edentulous dry human mandibles, with $1{\times}1mm$ gutta percha cones, placed in 5mm intervals posterior to the mental foramen on each side of the buccal part of the mandible, were used in this study. They were scanned as follows: 1) Single detector computed tomography: slice thickness 1mm, 200mA, 120kV 2) Multi-detector computed tomography: slice thickness 0.75mm, 250mA, 120kV 3) Cone beam computed tomography: 15mAs, 120kV Axial images acquired from three computed tomographies were transferred to personal computer, and then reformatted cross-sectional images were generated using V-Implant $2.0^{(R)}$ (CyberMed Inc., Seoul, Korea) software. Among the cross-sectional images of the gutta perch a cone, placed in the buccal body of the mandible, the most precise cross section was selected as the measuring point and the distance from the most superior border of the mandibular canal to the alveolar crest was measured and analyzed 10 times by a dentist. Results: There were no significant intraobserver differences in the distance from the most superior border of the mandibular canal to the alveolar crest (p>0.05). There were no significant differences among single detector computed tomography, multi-detector computed tomography and cone beam computed tomography in the distance from the most superior border of the mandibular canal to the alveolar crest (p>0.05). Conclusion: Multi-detector computed tomography and cone beam computed tomography are clinically useful in the evaluation of pre-operative site for mandibular dental implants, with consideration for radiation exposure dose and scanning time.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.2
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• pp.27-47
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• 1997

The purpose of this study was to evaluate the accuracy and usefulness of spiral tomography through the comparison and analysis of SCANORA cross-sectional tomographs and DentaScan computed tomographic images of dry mandibles taken by a SCANORA spiral tomographic machine and a computed tomographic machine. Thirty-one dry mandibles with full or partial edentulous areas were used. To evaluate the possible effect of location in the edentulous area, it was divided into 4 regions of Me (region of mental foramen), MI (the midportion between Me and M2), M2 (the midportion between mental foramen and mandibular foramen) and S (the midportion of the mandibular symphysis). A ZPC column (sized 4 mm x 5 mm) was seated on the edentulous regions of Me, MI, M2 and S using the acrylic stent. Then SCANORA spiral tomography and computed tomography were taken on the edentulous regions which contained the ZPC column. The ZPC columns and cross-sectional images of the mandible were measured in the radiographs by three observers and the differences between the two imaging modalities were analysed. The results were as follows: 1. In comparing the actual measurements of the ZPC column and measurements in the radiographs, the mean error of the DentaScan computed tomography was 0.07 mm in vertical direction and -0.06 mm in horiwntal direction, while the mean error of the SCANORA spiral tomography was 0.06 mm in vertical direction and -0.12 mm in horizontal direction. There was a significant difference between the two radiographic techniques in the horizontal measurement of the ZPC column of the symphysis region (p<0.05). But there was no significant difference in the measurements of other regions (p>0.05). 2. In measurements of the distance from the alveolar crest to the inferior border of the mandible (H), and of the distance from the alveolar crest to the superior border of the mandibular canal (Y), there was no significant difference between the two radiographic techniques (p>0.05). 3. In measurements of the distance from the lingual border of the mandible to the buccal border of the mandible (W), and of the distance from the lingual border of the mandible to the lingual border of the mandibular canal (X), there was a significant difference between the two radiographic techniques in measurements of the midportion between the mental foramen and the mandibular foramen (M2) (p<0.05). But there were no significant differences in measurements of the other regions of symphysis (S), mental foramen (Me), the first one-fourth portion between the mental foramen and the mandibular foramen (M1) (p>0.05). 4. Considering the mean range of measurements between observers, the measurements of SCANORA spiral tomography showed higher value than those of DentaScan computed tomography, except in measurements of symphysis (S). 5. On the detectability of the mandibular canal, there was no significant difference between the two radiographic techniques (p>0.05). In conclusion, SCANORA spiral tomography demonstrated a higher interobserver variance than that of DentaScan computed tomography for implant site measurements in the posterior edentulous area of the mandible. These differences were mainly the result of difficulty in the detection of the border of the mandible in SCANORA spiral tomography. But considering the cost and the radiation exposure, SCANORA spiral tomography can be said to be a relatively good radiographic technique for implant site measurement.

• Korea Trade Review
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• v.41 no.4
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• pp.157-183
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• 2016

This study examines the effects of the acquirer's experience on cross-border mergers and acquisitions(CB M&A) performance. We posit that various types of experience on M&A, including heterogeneity of experience, strategic alliance experience, first CB M&A, domestic and CB M&A experience may have an influence on the performance of CB M&A. The hypotheses are tested with multiple regression on global M&As made by Korean firms over the period of more than fifteen years. The empirical results indicate that firms with domestic M&A experience and the ones with CB M&A experience improve firm performance. Specifically, CB M&A experience more strongly and positively affects CB M&A performance. It also reveals that M&A experience and first CB M&A positively affect CB M&A performance. However, heterogeneity of experience negatively affects CB M&A performance and it has found no significant relationship between strategic alliance and firm performance. In addition, data show that the better explanation is an overall U-shaped relationship than a linear one between CB M&A experience and Performance. Overall, this study contributes to the literature on CB M&A by examining the effect of various types of experience such as heterogeneity of experience and alliance experience and offering a different explanation based on experience, more specifically, addressing the negative relationship between heterogeneity of experience and M&A performance.

• ETRI Journal
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• v.24 no.1
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• pp.56-64
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• 2002

This paper investigates how market participants react to mergers and acquisitions (M&As) involving telecommunications companies. The empirical evidence suggests that such activities convey bad news to the market. This is consistent with the synergy trap hypothesis and extant empirical findings of value-reducing diversification strategies in recent literature. The evidence also indicates that a cross-border, rather than a domestic M&A deal, is the main driver of the negative market reaction. Further, our evidence of negative impacts on the bidder's business after an M&A reinforces our main finding that market participants, on average, perceive M&A activities to be detrimental to shareholder value. This suggests that value creation or synergy through an M&A deal is not warranted even though it can generate an increase in size of the firm.

• Management & Information Systems Review
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• v.35 no.4
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• pp.79-98
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• 2016

A large number of Chinese enterprises have grown up and become increasingly competitive. Chinese firms have ventured abroad to search for new sources of growth. Overseas mergers and acquisitions of Chinese companies has been developed rapidly through extensive opening policy and active support system by government. The main purpose of this study is to identify the factors that affect the outcomes of overseas mergers and acquisitions made by Chinese firms in recent years, particularly, financial performance of the acquiring firms. This study aims to analyze systematically financial performance and its determinants of Chinese overseas M&A in recent years. This study chooses a sample of 167 overseas mergers and acquisitions in the manufacturing industry in China and the relevant data were collected during the period 2006 to 2012. The data were analyzed by using a multiple regression analysis to identify determinants of corporate performance. We showed that cultural distance, past performance, state ownership, and interaction between cultural distance and past performance. Findings of this study can provide useful guidance to outward Chinese M&A in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.583-585
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• 1995

Following importation of temperate Australian breeds of sheep into Malaysia, it was demonstrated that there was variability in libido and semen productivity. Consequently, a study was conducted to determine the concentration of testosterone and relate it with libido and semen production. A total of 10 rams each of Dorset Horn, Cross of Merino with Border Leicester, Siamese Long Tail, Suffolk and local Malin were used to study the composition of testosterone in the blood plasma of these breeds. The study showed that there was significant difference between the testosterone level of different breeds in Spring and Summer but not in Autumn and Winter. The difference was pronounced in August and January. A significant difference (p > 0.05) was recorded in the testosterone levels of the different breeds during the day where Malin had better libido compared to the other breeds. There was no significant difference between the testosterone levels of the different breeds at night. The testosterone level of Suffolk, however, was elevated throughout the night (2.00 ng/ml and over) which resulted in better libido at night compared to the other breeds.

• Korea Trade Review
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• v.47 no.4
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• pp.233-254
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• 2022

Although there is growing literature evidence of linkages between global value chains (GVCs) and foreign direct investment (FDI), the results are mixed and ambiguous by geographic dimension, time period and sectoral scope. Moreover, bilateral approaches on these connections have been rarely analyzed. In this context, we investigate the effect of bilateral greenfield FDI and cross-border M&A on GVC linkages between host countries and source countries. We match three-year averages of bilateral FDI and UNCTAD-Eora GVC value-added data from 2005 to 2019 between 37 OECD sources and 176 host countries (37 OECD versus 139 non-OECD countries). In the structural gravity model, the empirical specification includes bilateral and country-period fixed effects and uses a Poisson Pseudo-Maximum Likelihood (PPML) estimator. We find that greenfield and M&A FDI promote forward and backward GVC linkage for all sectors between OECD countries, whereas greenfield FDI promotes backward GVC linkage between OECD and non-OECD countries. In addition, the results indicate that the degree of influence of GVCs by FDI flows is greater for forward GVC than backward GVC among OECD countries.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.175-178
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• 1994

A study was conducted at Ijok, Malaysia, to determine the relationship of testicular measurements with libido and semen quality in tropical and imported temperate breeds of sheep. Ten rams each of Malin (M), Siamese Longtail (L), Cross of Merino with Border Leicester (C), Dorset (D) and Suffolk (S) were used for the study. Libido, semen volume and semen quality were recorded monthly for a year together with testicular length, width and circumference. The results showed that there were breed differences in volume and quality of semen where the tropical breeds had better semen compared to the temperate breeds. There was positive and significant correlation between testicle length and semen volume in all the breeds. Testicular length was found to be positively and significantly correlated with motility and sperm concentration in the tropical breeds (L and M). The relationship between libido and testicle measurements in the tropical breeds was not significant (p<0.05). There was variable relationship between the testicular measurements and libido in the temperate breeds where the relationship was significant and negative in breeds C and D and highly significant and positive in S. It was evident that the long testicles influenced the quality of the semen whereas testicles with greater circumference influenced the libido of the rams.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.989-992
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• 2015

해외 글로벌 쇼핑 사이트들을 통한 직접 구매를 일컫는 해외직구 금액이 2013년 5881억원 발생하며, 대한민국 전체 경제의 0.2%를 차지하게 되었다. 구입지역도 미국 뿐만 아니라 중국, 독일로 점차 확대되고 있다. 해외직구의 시장은 향후에도 지속적으로 증가 될 것으로 예측되는데, 이처럼 해외직구가 발전하게 된 성장 배경에는 내수시장보다 저렴한 가격, 해외 온라인 쇼핑 사이트들의 진화, 전문 배송업체의 등장, 커뮤니티 정보 공유 활성화 등으로 인하여 해외직구에 대한 폭발적인 반응으로 연결된 것으로 보인다. 하지만 최근에 정치권의 움직임은 해외직구를 규제하여 통제하려는 움직임이 크다. 제 물품을 확인하지 않고 목록 신고만으로 수입통관이 허용되어 허위 신고 가능성이 높아졌다는 것과 이에 따른 관세 탈루 및 마약을 비롯한 수입금지 물품의 국내 반입 위험성 또한 증가한다고 정부는 말하고 있다. 이것은 매우 잘못된 해석으로 판단된다. 소비자들의 소득 발생으로 인한 소비 할 수 있는 절대치는 감소하고 있는데도 불구하고, 국내 대기업들의 상품 판매 하락이 합리적인 가격으로 판매하고 있는 해외 사이트들로 피해자가 된듯한 표현을 하여, 해외 제품을 구매하려는 소비자를 규제한다는 것은 어불성설에 해당된다. 소비자들은 항상 합리적인 선택을 추구하려고 하기 때문에 여러 가지 요소들을 고려한다. 이러한 소비자들의 심리를 파악하여 국내 소비자들이 불만을 가지고 있는 내수시장의 가격 부분에 대한 심리적 회유책을 적용하여 가격 경쟁력에 대한 인식을 새롭게 고려 할 수 있도록 하는 개선안을 제시해 본다.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.49-63
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• 2017

The purpose of this study is to analyze the effects of the collective characteristics of SMEs on M&A activity on the disclosure effect of mergers and long-term business performance after mergers. From 2000 to 2012, we examine 717 cases of small and medium-sized enterprises (SMEs) using multiple regression analysis and difference analysis. The results of this study are as follows. First, it is confirmed that the effect on the merger announcement effect is the same as the previous study on the Korean capital market listed companies except for the effect of diversification, listing effect, and cross-border effect. In addition, we have found that firms with higher performance in the past have higher excess returns in the disclosure effect of mergers and acquisitions. Second, unlike the previous studies that non-related mergers have a positive effect on long-term operating performance, for the characteristics of SMEs with lower market competitiveness than that of average listed companies, SMEs merging with same industry group companies have a positive effect on long-term operating performance. This study provides a new perspective on the merger and acquisition of SMEs by examining the effects of M&A announcement and long-term performance.