• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.58-65
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• 2014

A recent issued Internet of Things (IoT) is based on the service that everything around us is exchanging the information and reacting upon these information. These IoT services are mainly dealing with the information that was generated by the information nodes of IoT networks such as sensors, where the way how the information from information nodes should be dealt with is very important in terms of service reliability in IoT networks. This paper introduces a new scheme for service reliability and energy efficiency that is reducing the energy consumption of actuator node reacting upon the request messages from the information nodes in IoT networks.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.191-213
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• 2008

This study tests and reconfirms the wealth transfer of mergers and acquisitions(M&As) by examining the changes in and the relationship between shareholder and bondholder wealth after the announcements of M&As for the publicly listed firms in Korea Stock Exchange and KOSDAQ market during $1999{\sim}2006$. The change in shareholder wealth is measured by the Cumulative Abnormal Return(CAR) at the M&A announcements, and the change in bondholder wealth is calculated using the Yield Spread Change(YSC) and the change in acquiring firms' credit ratings. The empirical tests show that the CAR of 344 sample acquiring firms at the announcement is 3.59%, which confirms results of the prior research on M&As in Korean market. The average YSC for 35 sample acquiring firms between $2001{\sim}2006$ proves to be negative when we use the yield spread of firms with comparable credit ratings as a benchmark, which means that the acquiring firms' bondholders gain with the announcements of M&As. We find the same result using another benchmark-the yield spread of government bonds. The improvement in the acquiring firms' credit ratings one year after the M&As also indicates that the M&As, on average, increase bondholder wealth. Our test results are consistent with those of the existing studies on the effect of bondholder wealth after the M&As in the United States, which shows that the bondholder wealth increases after the M&As. We do not find the evidence that there is a wealth transfer from the acquiring firms' bondholders to the shareholders after the M&A announcements. Rather, this study confirms that the wealth of the acquiring firms' bondholders increases in the M&As in Korea.

• The Korean Journal of Financial Management
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• v.27 no.2
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• pp.145-167
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• 2010

We investigate the dynamic relationship between stock returns and investors' behavior. For the putpose of the paper, daily KOSPI returns are decomposed into two parts: overnight returns and daytime returns. Overnight return is measured by the closing price of the previous day and the opening price of the current day. And daytime return is measured by the opening and closing prices of the current day. Qvernight returns are assumed to reflect global economic information, and daytime returns, domestic or local information. Major results are as follows: Foreign investors' behavior has an effect on the overnight returns more than the daytime returns. Individual investors' behavior, however, has little effect on the overnight returns, but not the daytime returns. Consequently, forecast error variance decomposition shows that the variance explanation power of foreign investors is higher in overnight returns rather than in the daytime returns. And the variance explanation power of individual investors is higher in daytime returns rather than in overnight returns. It implies that foreign investors employ dynamic hedging strategies and give more weight to global economic information rather than to domestic information. We conclude that investment behavior of foreign investors and domestic individuals is based on different economic information. This paper's findings are consistent with the economic situation that the Korean capital markets have faced since the global financial crisis of August 2008.

• The Korean Journal of Financial Management
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• v.27 no.2
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• pp.85-114
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• 2010

Using the financial institutions that have adopted performance-based stock option plan, this paper examines whether performance-based executive stock options improves effectively firm value. Over the period 2002~2005, we investigate short-term and long-term effects of the performance-based stock options on stock price. The empirical results are summarized as follows. First, the announcement of plain vanilla stock options generates no significant effects on firm value. Meanwhile, the announcement of performance-based stock options results in negative and significant abnormal returns, which is contrary to the expectation. In addition, we find that there are strong, significant and negative announcement effects when banks grant performance-based stock options. Secondly, there is no significant difference between the long-term performance of the sample granting stock options and that of the benchmarks, which is similar to the findings of the previous research. Also, we fail to get any evidence that performance-based stock option awards have improved the long-term firm value.

• The Korean Journal of Financial Management
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• v.23 no.1
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• pp.1-47
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• 2006

This study investigated the effect of tender-offer on the value of the firms in Korea. For this purpose, the study applied an event study methodology to 55 cases(bidding firm : 26, target firm : 39) of tender-offer and 164 cases(bidding firm : 144, target firm : 20) of merger announcements made between January 1st, 1994 and September 30th 2004. We found the following results. For tender-offer announcements, there was a significant increase in target firm's value while there was no significant change in bidding firm's value. In contrast, for merger announcements, there was a significant increase in bidding firm's value while there was no significant change in target firm's value. In addition, the synergy effect of tender-offer was higher than that of merger. The results support the Berkovitch and Khanna(1991)'s prediction that bidding firms choose tender-offer rather than merger in the presence of higher synergy profit from M&A.

• Korean Business Review
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• v.16
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• pp.169-184
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• 2003

IR(Investor Relation) is an active management activity to provide well balanced information to investors which can reduce asymmetry of information between investors and management. This activity could contribute to the long-term development of corporation with increased mutual trust between investors and management. Consequently, in these days, ill is widely recognized as an effective measure of securing corporate transparency, maximization corporate value, and stock-holder oriented management. The purpose of this study is to examine the effect of corporate IR activity on investment behavior as well as stock price. It is assumed that if asymmetry of information between investors and management is cured by active ill activity from a corporation, with more transparent and reliable information of the firm at hand investors would more actively involved in trading. Statistically speaking, I assumed that the more information provided by ill activities, the higher value of a corporation at the stock trading.

• The Korean Journal of Financial Management
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• v.26 no.4
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• pp.165-189
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• 2009

According to disclosure regulation, insider can hide their trading until disclosure day, because there be interval between trading time and disclosure time. To accommodate strategic trade, they have an incentive to be brought disclosure interval as long as possible. This research investigate whether strategical behaviour of informed traders using disclosure intervals exists in domestic stock market.ls xt, we aney he whether they can get abnormal return through stealth strategy after announcement date. We also evaluate the effect of mimicking trading on price impact with the assumption of existence of mimicking trading. Our major research results are as follows: In case of main shareholder without having no prompt disclosure duty, the frequency of trading started at the beginning of month is shown significantly higher than others. This result shows a direct evidence that informed traders buy or sell their equity strategically using disclosure intervals. Also, we find the result that the coefficient of strategic variables has highest value in middle size information. However, the empirical evidence that informed trader get abnormal return through strategic trading was not shown in this study. Meanwhile, stock price over-reacts for selling transaction on trading point and is recovered after disclosure date., so we assume possibility of mimicking trading exists in domestic stock market.

• Applied Microscopy
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• v.27 no.1
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• pp.71-86
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• 1997

The regeneration and differentiation of the cutaneous pigment system in the goldfish, Carassius auratus during the wound healing process were studied with high magnification electron microscope. The cutaneous pigment cells of the normal tissues were composed of three kinds of dermal chromatophores-xanthophores, leucoiphores and melanophores. While xanthophores contain two kinds of pigment granules-pterinosomes and carotenoid vesicles, leucophores and melanophores contain amorphous pigment granules (leucosomes) and oval shaped electron dense melanin pigment granules (melanosomes) respectively. After injury, primary wound healing responses being carried out by migration of epidermal cells and hemocytes spreading over the wound surface at the day of wounding. And at the time of primary wound closure, 5 to 7 days after wounding, rER rich cells-presumably common precursors of dermal chromatophores-immigrated into the wound area. First redifferentiated chromatophores appeared 3 weeks after wounding. Pigment granules of the chromatophores were emerged from the cytoplasmic Golgi complex via rough endoplasmic reticulum. Pinocytotic vesicles which associated with accumulation of pigment material, appeared only at the inner surface of the chromatophores adhering to the rER rich cells, characteristically. The differentiation of each chromatophore in addition to integumental wound repair were accomplished within 4 weeks after wounding at most cases, however the total numbers and densities of these repaired chromatophores still primitive state. Moreover, It has been revealed that complete repair of chromatophores at wounded tissues from burns requirs more than 3 months in normal environment.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.23-32
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• 1998

The pathogenic potential of Acnnthamoebc strains was evaluated by experimental infection of murine AIDS (MAIDS) model. C57BL/6 mice were induced to immunocompromized state by intraperitoneal injection of LP-BM5 MuLV and revealed the typical splenomegalty and Iymphatic enlargement of axillar and inguinal regios on necropsy 4 weeks after viral infection. Although there was no significant difference in the mortality rate of MAIDS mouse according to the culture temperature, it was very different in the mortality rate from strain to strain of Accnthnmoebc. A. henIHi OC-3A strain isolated from the brain of a GAE patient showed !he highest mortality rate and A. culbertsoni A-1 strain from tissue culture was the second. KA/S3 and KA/S2 strains isolated from soil revealed very low virulence. The mice infected by intranasal inoculation of Acanthnmoebc showed relatively chronic course than intravenous inoculation. The gross findings of lungs and brains from infected mice were variable among mice. On the microscopic observations, the lungs showed much more severe inflammation and necrosis than the brains microscopically. This MAIDS model would be useful to study the opportunistic protozoan infections of AIDS patients. In the light of these results. the pathogenic potential and the virulence of Acnnthamoebo may be determined genetically.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.175-182
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• 2021

Focusing on the recently announced "KOSPI 200 ESG Index," this study intends to examine whether the "KOSPI 200 ESG Index" has any relevance to stock prices. Specifically, it was empirically analyzed whether companies included in the KOSPI 200 ESG index showed average abnormal return and cumulative average abnormal return of stock prices due to incorporation into the index. As for the research method, the case study was conducted using the return by the market model using the coefficient estimated by the OLS for the normal expected return. The study results are summarized as follows. First, the initial incorporation of a company into the KOSPI 200 ESG index showed significant positive(+) average abnormal return and cumulative average abnormal return. Second, the incorporation of a company into the KOSPI 200 ESG index showed significant positive(+) average abnormal return and cumulative average abnormal return. Through this study, it was confirmed that investors in the market are aware of ESG indicators as non-financial information, not just financial information. In addition, it can be said that the contribution of this study to the fact that investors perceive ESG index as information for investment. This study differs in that it uses the latest ESG index, but at the same time, it has limitations in that the study period is short and the study sample is limited.