• The Korean Journal of Financial Studies
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• v.10 no.1
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• pp.191-214
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• 2004

VaR에 의한 금융위험의 측정은 국제결제은행 바젤위원회의 내부모델 허용에 힘입어 금융산업에서 표준방식으로 확고한 입지를 차지하고 있다. 본 연구에서는 한국주식시장포트폴리오를 거래투자자산으로 보유한 경우의 VaR를 극단치이론에 입각하여 측정하고 이의 성과를 RiskMetrics의 성과와 비교하여 검토하였다. GPD의 모수적 추정에 의한 VaR의 사후검정결과는 표본내 사후검정이나 표본외 사후검정에서 어떤 신뢰수준에서도 기대되는 범위와 크게 벗어나지 않은 안정된 결과를 보였다. RiskMetrics의 EWMA방식도 역시 표본내와 표본외 사후검정 어느 경우에나 기대되는 범위에서 크게 벗어나지 않았지만 높은 신뢰수준에서는 그 성과가 GPD VaR에 비하여 상대적으로 불안정하였으며 위험의 과소평가 성향을 확인할 수 있었다. 비모수적 GEV추정에 입각한 VaR의 경우에는 위험을 과대평가하고 지나치게 보수적인 성향을 나타내었다. GPD의 모수적 접근에 의한 VaR 측정은 다양한 신뢰수준에서 정확한 검정결과를 보여주고 있으며, 시간적 흐름에 따르는 VaR의 행태도 지나친 변동성을 보이지 않아 외부규제 및 내부통제를 위한 금융위험의 측정지표로서 실용적인 가치가 있음을 확인할 수 있다.

• Journal of Conservation Science
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• v.37 no.5
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• pp.557-566
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• 2021

We investigated the properties of Korean traditional animal glue which are associated with the use of different parts of cattle hide and extraction conditions. Both average molecular weight(Mw, Mz) and polydispersity (PDI) of the animal glue increased with extraction time, whereas only PDI decreased after 48h. There were no differences in the average molecular weight and PDI for the different cattle hide parts used, although a individual difference was observed with regard to total molecular weight. Differences in extracts over time were compared by investigating the amide regions representing the gelatien component of the animal glue. The triple helix structure of the belly skin deteriorated in a manner proportional to the extraction time, and differences were observed for each cattle hide part. The yellowness increased with the extraction time; however, the viscosity was not proportional to the average change in molecular weight. This study has some limitations because of difficulties in the quality control of cases where small amounts of glue were extracted as small differences might impact the overall results considerably. Further research exploring various extraction conditions is required to ensure the prodiction of traditional animal glue with optimum qualities.

• Journal of Life Science
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• v.31 no.10
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• pp.960-968
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• 2021

Since microalgae research started on late 18 century, they have been recognized as one of the most important bioresources used in bioindustry. Owing to the large efforts paid to industrial application of this microorganisms, their importance on food/feed and bioactive compounds has been further extending into the environmental research areas including alternative energy resources, mitigation of the carbon emission, and waste-water treatment. However, despite the importance on their industrial application, the fundamental research field related to the long-term preservation of microalgae culture has not received much attention. However, a less labor intensive and cost-efficient preservation technology enabling biologically active and stable microalgae-culture provides a key success factor in the biotechnological application. Therefore, this study investigated various cutting-edge microalgae cryopreservation technologies currently developed so far, mainly targeting Chlorophyta, which occupies the largest taxon in the classification system of microalgae. In addition, for the development of successful cryopreservation technique, the key factors such as temperature control effect and preservative effect during cryopreservation of microalgae culture were investigated. In addition, the problems with current preservation technology that is being used in Korean domestic biological resource banks and the international microalgal resource banks are described. According to our investigation, currently no standard method for long-term preservation of microalgae is available due to their various morphological and physiological characteristics. To overcome such issues, much more efforts on fundamental research area on the identification of specific biomarker used for microalgae taxonomical classification and further systemic approaches based on strain-specific cryopreservation methods needed.

• Economic Analysis
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• v.24 no.3
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• pp.1-36
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• 2018

When it comes to explaining the relationship between inventory investment and business fluctuations, the production smoothing theory and the stock-out avoidance theory take contradictory stances. Decision-making related to inventory investments of corporations is thought to be influenced by both motives, but the relative sizes or directions of their respective influences can differ depending upon the phase of the business cycle. Against this backdrop, this paper differs from existing studies in that it theoretically tests the relative significances of the production smoothing and stock-out avoidance motives in the inventory investment dynamics, while placing its analytical focus on determining the existence and patterns of the asymmetric dynamics of inventory investment over the business cycle phases. To this end this paper sets up a non-linear model that is expanded from the existing linear inventory investment model, and checks whether its predictive power is better than that of the existing model. The results of analysis confirm the nature of the asymmetric dynamics of inventory investment over the business cycle phases. A stock-out avoidance motive appears but there is no significant production smoothing motive in boom times. In downturns, in contrast, the stock-out avoidance motive is insignificant, but a quality of asymmetric dynamics in which changes in inventory cause the deepening of recessions, due to the non-convexity of production costs proposed by Ramey (1991), is detected. This paper confirms that a model considering the asymmetric dynamics of inventory investment can have better predictive power than one that does not consider it, through within-sample and out-of-sample predictions and various predictive power tests. These research results are expected to be useful for economic forecasting, through their enhancement of the understandings of the inventory investment dynamics and of the nature of its business cycle destabilization.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.2
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• pp.69-80
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• 2003

Verifiable encryption is an encryption technique with which one can verify what has been encrypted even if one can not decrypt the ciphertext. This technique can be used in fair exchange to convince the counterpart of his or her receiving an item by presenting an encrypted form in advance. In this paper, a method that can guarantee the payment atomicity is proposed by applying verifiable encryption to an electronic cash system based on the representation problem. With the new method, the process of dispute settlement is improved in the fact that the trusted third party do not have to interact with the bank to resolve disputes. This method is also flexible in a sense that clients and shops can request for dispute settlement regardless of any deadline constraint. However, additional proof is necessary to apply verifiable encryption during payment. We discuss the security and the atomicity of our method, and compare ours with others.

• Management & Information Systems Review
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• v.29 no.4
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• pp.207-223
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• 2010

One of the important prudential regulations is the capital regulation. The current domestic and international capital regulation sets the minimum capital requirement according to the size of risk which is the simple sum of market risk and credit risk. However the portfolio theory suggests that, due to the effect of diversification, the total risk is less than the summation of market and credit risk. This paper investigates and does empirical test to verify the diversification effect in measuring financial firm's integrated risk. We verify the diversification effect between the market risk and credit risk. This paper's contribution is to present the empirical evidence that, considering the relationship between market and credit risk, the integrated risk is less than sum of them. This implication is that the surplus capital may be used for the other purposes, therefore enhancing capital allocation efficiency in view of society as a whole.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.505-509
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• 2016

This study was conducted to examine the effectiveness of various dressing materials applied to tree wounds in Korea. Significantly higher wound closure rates than those of controls were found when thiophanatemethyl paste (Topsin Paste$^{(R)}$) was applied to Ginkgo biloba, Zelkova serrata, and Prunus yedoensis; lanolin to Z. serrata and P. yedoensis; and tebuconazole paste (Silvacur$^{(R)}$) to P. yedoensis. However, significantly lower wound closure rates than those of controls were found when petroleum jelly (Vaseline$^{(R)}$) was applied to G. biloba, Z. serrata, and P. yedoensis. It was noted that the wounds of Z. serrata and P. yedoensis treated with petroleum jelly expanded due to the death of cambium located at the edge of the wounds. Wound closure rates applied with adhesive - non-toxic to human body (Okong bond$^{(R)}$) were also significantly lower than those of controls in Z. serrata. Pinus densiflora showed no reaction to any experimental wound dressing because of resin secreted from the exposed cambium.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.941-950
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• 2015

Internet banking is widely used in our life with the development of the internet. At the same time, phishing attacks to internet banking have been increased by using malicious object to make unfair profit. People using internet banking service in Korea is required to install security modules such as anti-virus and keyboard protection. However phishing attack technique has been progressed and the advanced technique such as memory hacking defeats the security module of internet banking service. In this paper, we describe internet banking security modules provided by Korean internet banks and analyze how keyboard encryption module works. And we propose an attack to manipulate account transfer information using javascript. Although keyboard protection module provides two functions that protect leakage and manipulation of account transfer information submitted by users against the malicious program of hackers. Our proposed technique can manipulate the account transfer information and result html pages.

• KDI Journal of Economic Policy
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• v.29 no.2
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• pp.117-133
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• 2007

This paper evaluates the efficiency of monetary policy in Korea within the framework of interest rate feedback rules. For this, a small open macroeconomic model is constructed in a similar fashion to Ball (1999). The model is shown to capture key features of the Korean economy well. Using this estimated model, optimal instrument rules are derived for a set of different monetary policy objectives. Empirical results find that the actual monetary policy in the class of instrument rules was not very effective in stabilizing the output gap relative to inflation. However, seemingly successful inflation stabilization observed in the data are not consistent with the policy rules as the reaction of the interest rate to inflation is very low. It also appears that the central bank did not react right to movements in the real exchange rate. This paper offers some suggestions for the conduct of monetary policy in Korea.

• Plant Journal
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• v.11 no.1
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• pp.30-38
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• 2015

This study is about whether the new Project Finance scheme called "Asset Backed Short Term Bond(ABSTB)" with Project Finance Guarantee Cover provided by Korean Exim Bank(KEXIM) is an appropriate and valid financing structure, through close examinations on domestic and overseas IPP case studies. This study clearly indicates that (i) the interest rate of ABSTB with KEXIM's Project Finance Guarantee is relatively more competitive than the interest rate of other ABSTB guaranteed by EPC Companies (ii) the lower credit rated EPC companies make higher ROE(Return on Equity) through this financing structure. Lastly, Korean EPC Companies can secure profitability through this innovative financing scheme which will also lead to winning more power plant Contracts and become globally competitive.