• Management & Information Systems Review
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• v.12
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• pp.137-160
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• 2003

The association between accounting earnings and the stock price of an entity is the subject that has been most heavily researched during the past 25 years in accounting literature. Researcher's common finding is that there are positive relationships between accounting earnings and stock prices. However, the explanatory power of accounting earnings which was measured by $R^2$ of regression functions used was rather low. To be connected with these low results, The prior studies propose that there will be additional information, errors in variables. This study investigates empirically determinants of earnings response coefficients(ERCs), which measure the correlation between earnings and stock prices, using earnings level / change, as the dependent variable in the return/earnings regression. Specifically, the thesis tests whether the factors such as earnings persistence, growth, systematic risk, image, information asymmetry and firm size. specially, the determinable variables of ERC are explained in detail. The image / information asymmetry variables are selected to be connected with additional information stand point, The debt / growth variables are selected to be connected with errors in variables. In this study, The sample of firms, listed in Korean Stock Exchange was drawn from the KIS-DATA and was required to meet the following criteria: (1) Annual accounting earnings were available over the 1986-1999 period on the KIS-FAS to allow computation of variables parameter; (2) sufficient return data for estimation of market model parameters were available on the KIS-SMAT month returns: (3) each firm had a fiscal year ending in December throughout the study period. Implementation of these criteria yielded a sample of 1,141 firm-year observation over the 10-year(1990-1999) period. A conventional regression specification would use stock returns(abnormal returns) as a dependent variable and accounting earnings(unexpected earnings) changes interacted with other factors as independent variables. In this study, I examined the relation between other factors and the RRC by using reverse regression. For an empirical test, eight hypotheses(including six lower-hypotheses) were tested. The results of the performed empirical analysis can be summarized as follows; The first, The relationship between persistence of earnings and ERC have significance of each by itself, this result accord with one of the prior studies. The second, The relationship between growth and ERC have not significance. The third, The relationship between image and ERC have significance of each by itself, but a forecast code doesn't present. This fact shows that image cost does not effect on market management share, is used to prevent market occupancy decrease. The fourth, The relationship between information asymmetry variable and ERC have significance of each by. The fifth, The relationship between systematic risk$(\beta)$ and ERC have not significance. The sixth, The relationship between debt ratio and ERC have significance of each by itself, but a forecast code doesn't present. This fact is judged that it is due to the effect of financial leverage effect and a tendency of interest.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.3
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• pp.178-192
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• 2006

The buffer overflow attack is the single most dominant and lethal form of security exploits as evidenced by recent worm outbreaks such as Code Red and SQL Stammer. In this paper, we propose microarchitectural techniques that can detect and recover from such malicious code attacks. The idea is that the buffer overflow attacks usually exhibit abnormal behaviors in the system. This kind of unusual signs can be easily detected by checking the safety of memory references at runtime, avoiding the potential data or control corruptions made by such attacks. Both the hardware cost and the performance penalty of enforcing the safety guards are negligible. In addition, we propose a more aggressive technique called corruption recovery buffer (CRB), which can further increase the level of security. Combined with the safety guards, the CRB can be used to save suspicious writes made by an attack and can restore the original architecture state before the attack. By performing detailed execution-driven simulations on the programs selected from SPEC CPU2000 benchmark, we evaluate the effectiveness of the proposed microarchitectural techniques. Experimental data shows that enforcing a single safety guard can reduce the number of system failures substantially by protecting the stack against return address corruptions made by the attacks. Furthermore, a small 1KB CRB can nullify additional data corruptions made by stack smashing attacks with only less than 2% performance penalty.

• 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.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.71-75
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• 1985

The clinical state with EEG pattern similar to interval discharge of epileptics is named as latent epilepsy, which does not necessarily mean that the patient will develop epilepsy later. However, since there is possibility of developing epilepsy on later date, antiepileptic mainly dilantin was tried to control the abnormal EEG. Since January to October 1985, total 580 headache sases with more than moderately abnormal EEG Visited the Neurology clinic. Among them 162 cases with interval seizure pattern (ISP) of epilepsy were selected for the study. The main ISP was 1. diffuse theta and/or delta bursts and 2. spikes. Since the study is only analysis of clinical treatment of 162 cases Without previous planning based on financial aid, about 30% of the patients did not return after the 1st EEG examination, in 42% failed to follow the EEG after the treatment and only remaining 28% of the cases were studied. Among 29 patients who were treated with Dilantin 100mg tid po, 16 improved and 13 not. Of the 13, 4 showed partial Improvement and partial progression. Case 1. In 4 weeks of antiepileptic the ray (AR), spikes disappeared but in 2 months developed bursts. Case 2. In 17days of AR, spikes and bursts disappeared but in 3 months bursts reccured. Case 3. In 1 week of AR, bursts disappeared but spikes developed. Case 4. In 3 months of AR, no change of spikes and bursts and she discontinued the AR. In 6 months she developed grandmal seizure. Eighteen cases, treated with other drugs except antiepileptics, all showed improvement. The other drugs were vincaprol, polygammalon, aronamin, ATP and hydergine. The improved cases had spikes more often than theta bursts. In view of the small number of the cases due to dropping most patients out of present study, it is considered meaningless to perform statistical analysis. Further well planned study With more patients is to be expected.

• Management & Information Systems Review
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• v.33 no.2
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• pp.263-279
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• 2014

SPAC(Special Purpose Acquisition Company) is the paper company that aims the merger of private company only, and introduced in Korea at 2009. Until 2013, 22 SPACs were listed, and 10 of them made successful mergers but rest were delisted. When IPO, range of the volume of public offerings were 20~30 billion won. After IPO, some SPACs showed extreme price movements, but on average their prices were below IPO prices 1 year later and near IPO prices 2 years later. Successful SPACs showed positive and significant 2.94% 25 days Cumulative Average Abnormal Return(CAAR) before the public announcements of merger and also showed positive and significant 10.60% 45 days CAAR around the general meetings of shareholders. I concluded that SPAC market were constrained by several regulations, so deregulation is needed for SPAC market activation.

• Journal of Korean Society of Forest Science
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• v.74 no.1
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• pp.82-87
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• 1986

Noticed that large number of the Korean white pine (Pinus koraiensis S. et Z.) has lost its typical excurrent tree from by removal of apical shoot in the process of cone harvesting, the investigation and analysis for the species were made on the basis of the relationship among DBH, total height, merchantable height, and merchantable volume, compared with normally grown Japanese larch (Larix leptolepis Gordon). One hundred sample trees for each species were selected in the same aged stands for the study. Results have indicated that the pine has shown abnormal height growth pattern mainly by the disturbance of external artificial force. The pine's forked and/or crooked stems by the reason lave led the result of less merchantable volume in the same DBH classes. Consequently, the pine would have undesirable tree form in terms of timber production, unless free from apical shoot disturbances. Considered to the merit of the Korean white pine that can produce timber and pine nuts, management alternatives for the pine stand were suggested to achieve maximum rate of return for the silvicultural investment.

• The Korean Journal of Financial Management
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• v.8 no.1
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• pp.139-153
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• 1991

This paper examines the pecuniary effects stemming from insider trading in the equities of firms targeted for acquisition. Illegal exchanges by those having advantageous information are found to result in excessive returns to stockholders of the sought firms. However, unusual market activities are not typical immediately subsequent to the illegal trading date, suggesting that nonpublic information is synthesized by market mechanisms with sufficient speed so that others cannot profit by imitating the better informed traders. The obtained evidence does not support the contention that insider trading on nonpublic information harms the outsider stockholders of involved firms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2108-2114
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• 2011

I examine propping within chaebolgroups, using changes of bond rating events made by corporate credit evaluation institutions. Much studies related to the internal capital market and tunneling have enhanced our understanding of the important function of chaebolgroups in emerging market, but relatively little is known about propping within affiliated firms. In a common sense, propping implies capital reallocation within affiliated firms to save a financially troubled affiliate. In event study on announcement the changes of corporate bond rating, I found most positive numbers in chaebolgroup's CAR. Particularly when lower change than higher change, decrease ratio of CAR is higher positively in chaebolgroups, which relatively shows that there is more propping effects in chaebolgroups than non-chaebolgroups. In multi-regression analysis, after strengthen restriction of internal mutual investment, propping effects are decreased positively in chaebolgroups than non-chaebolgroups when credit rating adjust lower, which implies there was more propping in chaebolgroups.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.81-101
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• 2003

The financial statements purpose to provide useful information to decision-making process of business managers. The value-relevant information, however, embedded in the financial statement has been often overlooked in Korea. In fact, the financial statements in Korea have been utilized for nothing but account reports to Security Supervision Boards (SSB). The objective of this study is to develop earnings forecasting models through financial statement analysis using artificial intelligence (AI). AI methods are employed in forecasting earnings: artificial neural networks (ANN) for manufacturing industry and case~based reasoning (CBR) for banking industry. The experimental results using such AI methods are as follows. Using ANN for manufacturing industry records 63.2% of hit ratio for out-of-sample, which outperforms the logistic regression by around 4%. The experiment through CBR for banking industry shows 65.0% of hit ratio that beats the statistical method by 13.2% in holdout sample. Finally, the prediction results for manufacturing industry are validated through monitoring the shift in cumulative returns of portfolios based on the earning prediction. The portfolio with the firms whose earnings are predicted to increase is designated as best portfolio and the portfolio with the earnings-decreasing firms as worst portfolio. The difference between two portfolios is about 3% of cumulative abnormal return on average. Consequently, this result showed that the financial statements in Korea contain the value-relevant information that is not reflected in stock prices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.431-436
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• 2009

As the telecommunication lines bring into widespread use, one of the most important aspects related to power distribution systems is effectively to evaluate the effect on the telecommunication lines from power lines. One of the efficient methods to evaluate the effect is to measure the induced voltage of a telecommunication line as a result of a ground-loop. If the power lines cause high induced voltage, the ground reference in the telecommunication lines is no longer a stable potential, so signals may ride on the noise. A ground loop is common wiring conditions where a ground current may take more than one path to return to the grounding electrode at the arrangement between the power lines and telecommunication lines. When a multi-path connection between the power lines and telecommunication line circuits exists, the resulting arrangement is known as a ground loop. Whenever a ground loop exists, there are potential for damages or abnormal operations of the telecommunication lines. The power lines can induce the voltage on the communication line. The effects can be calculated by considering the inductances and capacitances. However, if we assume that there are only power lines, it doesn't have a practical meaning because there are conductors with other purpose in the neighborhood of the lines. If we consider that case, we need more complex system. Therefore we suggest more complex system considering the conductors with other purpose in the neighborhood of the lines. The neutral wires and the overhead ground wires are considered for calculating the induced voltage. We assume that there are the messenger wires beside the power line as a result of increased use of them. The main purpose of this paper is a study on a shielding effect of messenger wires in the distribution lines. EMTP(Electro-Magnetic Transients Program) program is used for the induced voltage calculation.