• Korean Journal of Environment and Ecology
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• v.18 no.3
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• pp.340-345
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• 2004

The embryotoxic effects of PCB (Aroclor 1248) on a Korean frog, Rana dybowskii was deter-mined by using the FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol. The rates of mortality and malformed larvae were investigated by probit analysis. The results showed that PCB is highly embryolethal. From LC$_{50}$ of 1.48ppb and from EC$_{50}$ of 0.25ppb and TI of 5.7 were derived, which indicates PCB is to be considered a teratogenic compound. Specific malformations occurred in 62.0% as edema at the 0.1ppb, in 32.0% as tail deformations at the 1ppb, and in 68.0% as profound deformations at the 5ppb of PCB concentration which living embryos were exposed to. PCB suppressed the growth of head-tail length at a relatively low concentration (1.0ppb), and therefore growth inhibition as assessed by embryo length can be used as a sensitive indicator to evaluate the toxicity of pollutants in the environment. In conclusion, PCB must be considered highly embryotoxic to Rana dybowskii.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.115-123
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• 2021

This study investigated the functional study in anti-oxidant and anti-melanin activity by Desmarestia dudresnayi subsp. Tabacoides, Desmarestia viridis, Desmarestia ligulate leaf extracts. The DPPH radical scavenging activity of D. viridis extract showed a high antioxidant activity of 68.0 ± 1.9% at the concentration of 2.5 mg / mL, the ABTS and scavenging activity showed a high antioxidant activity of 84.6 ± 1.7% at the concentration of 2.5 mg / mL, and the NO radical scavenging activity was 2.5. It required a high antioxidant capacity of 91.6 ± 1.1% at mg/mL concentration. In addition, in B16F10 cells, at a concentration of 100 ㎍/mL, D. viridis extract is 35.0 ± 1.7% melanin among, which has the lowest amount of melanin among the three species. With these contents, it seems that there is a possibility that D. viridis could be developed as a cosmetic material. These results D. viridis considered that it can be used as a natural cosmetic material such as anti-oxidant and anti-melanin activity.

• Korean Journal of Cognitive Science
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• v.27 no.3
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• pp.469-499
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• 2016

The present study investigated the cognitive mechanism underlying online processing of Korean syntactic (for example, A bed/a clock belongs to/doesn't belong to the furniture "침대는/시계는 가구에 속한다/속하지 않는다") and lexical negation (for example, A tiger/a butterfly has/doesn't have a tail "호랑이는/나비는 꼬리가 있다/없다") using an ERP(Event-related potentials) technique and a truth-value verification task. 23 Korean native speakers were employed for the whole experiment and 15's brain responses (out of 23) were recorded for the ERP analysis. The behavioral results (i.e. verification task scores) show that there is universal pattern of the accuracy and response time for verification process: True-Affirmative (high accuracy and short latency) > False-Affirmative > False-Negated > True-Negated. However, the components (early N400 & P600) reflecting the immediate processing of a negation operator were observed only in lexical negation. Moreover, the ERP patterns reflecting an effect of truth value were not identical: N400 effect was observed in the true condition compared to the false condition in the lexically negated sentences, whereas Positivity effect (like early P600) was observed in the false condition compared to the true condition in the syntactically negated sentences. In conclusion, the form and location of negation operator varied by languages and negation types influences the strategy and pattern of online negation processing, however, the final representation resulting from different computational processing of negation appears to be language universal and is not directly affected by negation types.

• JOURNAL OF ELECTRICAL WORLD
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• s.308
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• pp.76-79
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• 2002

이제 기업별로 분기이익을 발표하는 Earning Season이 돌아왔다. 분기보고에 나타난 실적을 기초자료로 하여 기업들은 내부적으로 자사의 성과를 평가하고 주식시장에서는 투자자들이 기업을 평가하는 기본 자료로 활용하여 온 것이 주지의 사실이라고 할 수 있다. 그러나 엔론사태를 시발로하여 현재까지 꼬리를 물고있는 미국 기업에 대한 회계조작 사건은 기업회계에 대한 신뢰성의 저하를 초래했다. 세계에서 가장 투명한 경영을 한다는 미국의 대기업들이 이러한 사건에 연류되면서 상대적으로 투명성이 의심되는 국가의 기업들은 회계조작과 관련이 없더라도 이러한 악재를 피해 가기는 힘든 것이 현실이다. 회계의 투명성에 대한 신뢰도는 단순한 문제라고 할 수만은 없다. 왜냐하면 회계의 신뢰성에 대한 문제는 기업의 펀드멘탈에 관련된 문제이기 때문이다. 이러한 연유로 자본주의 경제와 불가분의 관계인 회계에 대한 비판과 개혁론이 대두되고 있어 대안적인 방안들이 관심을 끌고 있다. 그 방안의 하나로 지목되는 것이 $''$기업 건전성 지수$''$이다. 기업 건전성 지수는 경영자의 기업관리 및 투자자의 기업평가에 동일하고 유용하게 쓰일 수 있는 재무적 접근법이다. 본 논고에서는 기업 건전성지수에 대한 개념, 활용방안, 회계조정 그리고 지표의 진정한 효과에 대하여 설명하고자 한다.

• The Korean Journal of Applied Statistics
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• v.8 no.1
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• pp.119-131
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• 1995

Based on Monte-Carlo simulation results we propose a robust analysis of variance procedure by utilizing trimmed mean and Winsorized variance. We deal with mainly the one-way classification case. We evaluate the empirical distribution of a pseudo-F statistic based on symmetrically Winsorized sum of squares when the population is normally distributed.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.42-42
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• 1999

본 연구에서는 극 저 에너지 이온 주입에 관한 연구를 위하여 새로이 제안된 PLDAM(phenomenological local damage accumulation model)을 효과적인 분자동역학 이온 주입 분포 계산 방법(highly efficient molecular dynamics (MD) schemes)에 적용하여 극 저 에너지 이온 주입에 관하여 연구하였다. PLDAM은 셀에 축적된 에너지와 이온 발생 순서(history of recoil event) 및 열 전도를 고려하여 실리콘 자기 이완과 재결합을 고려하고 있다. 효과적인 분자동역학 이온 주입방법으로는 MDRANGE code를 사용하였다. 국부적인 격자결함을 고려하지 않은 MDRANGE의 결과는 불순물 분포의 실험치와 꼬리 부분에서 많은 차이를 보여주었다. 그러나 본 연구에서 사용된 국부적인 격자결함 축적을 고려한 MDRANGE의 결과는 극 저 에너지 이온 주입 실험치와 잘 일치하였다. 또한 본 연구에서는 <100> 실리콘 기판 위의 0.1$\mu\textrm{m}$$\times$0.1$\mu\textrm{m}$ 영역에 도즈에 해당하는 이온만큼을 주입하여 불순물 분포를 계산하였다. 붕소와 비소의 경우에, 도즈와 이온주입 에너지가 증가하에 따라서 국부적으로 축적된 격자결함이 불순물의 분포에 미치는 영향이 커지는 것을 알 수 있었다. 특별히 이온 주입 에너지와 함께 무관하게 도즈 1014/cm2 이상에서는 국부적으로 축적된 격자 결함이 불순물의 분포에 크게 영향을 미치는 것으로 나타났다.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.50-59
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• 1999

This paper is concerned on the generation of an optimal section of wing in ground effect by a SQP method which is one of nonlinear optimization techniques. A potential panel method is used for the flow analysis and the ground effect is taken into account by an image method. The numerical method is first verified by an inverse problem where a shape of wing section is sought for the prescribed pressure distribution. The purpose of the present paper is to generate a wing section which can give a maximum lift subjected to the design constraints including the height stability which is important in the WIG design. The effect of the tail wing is also included.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.37-46
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• 2004

Several notes on ground effects drawn from Navier-Stokes analyses and their aerodynamic interpretations were addressed here; For two-dimensional ground effect, the change of surface pressure due to image vortex, the venturi effect due to thickness and the primary inviscid flow phenomena of ground effect, and for three-dimensional ground effect, strengthened wing tip vortices, increased effective span and the outward drift of trailing vortices. Irodov's criteria were evaluated to investigate the static longitudinal stability of conventional NACA 6409 and DHMTU 8-30 airfoils. The analysis results demonstrated superior static longitudinal stability of DHMTU 8-30 airfoil. The DHMTU airfoil has quite lower value of lrodov's criterion than the conventional NACA airfoil, which require much smaller tail volume to stabilize the whole WIG-craft at its design stage.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.11-21
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• 2013

The conventional real-time signal control strategy for oversaturated situation generally requires a number of detectors at the intersection in order to identify the queue length at each approach. Also, existing strategy for the spillback has limited effect due to the temporal spillback control which only reduce the green split at the approach. In this study, a signal control system utilizing the imagery information from ITS roadside equipment is developed for operation of oversaturated intersections. The strategy calculates the saturation ratio based on the queue length extracted from ITS RSE, and designs the signal control variables according to the saturation ratio. The signal control strategy is divided into two phases: oversaturated and supersaturated. In oversaturated conditions, timing plan for main approach is optimized by the queue length. In oversaturated conditions where spillback might occur, the signal timing is designed in order to avoid the spillback. To increase field adaptability, the strategy is designed to adjust the split length, all-red-time, and clearance time, and keep the major signal control variables intact. The result of the simulation shows that in oversaturated conditions, the improvement is similar to the real-time signal control system. In case of, oversaturated conditions, however, the effect of the strategy is superior to that of a real-time system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.3_4
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• pp.112-122
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• 1973

Philometroides carassii (ISHII, 1931) is a parasitic nematode of Carassius auratus and gold fish. Recently a large number of parasitized fishes by this nematode have been reported by fish farmers in Korea. The present investigation was aimed to find out the life cycles of the parasites and effects of chemotherapeutic medicines on the emerged larvae from the adult parasites. Results of the study are summarized as follows : 1. Intermediate host of p. cararsii is a freshwater copepod, Cyclops sp. and the invaded lavae in the body cavity of copepod are capable for parasitizing the fish host after 3 hours of invasion. 2. The lavae eaten directly by the fish host are digested or excreted. 3. The larvae invaded in the fish intestine through the intermediate host pass into the body cavity in 1 to 10 days, and become subadult stage. After 18 to 20 months the subadults parasitic in the body cavity of the Carassius auratus, penetrate through muscle fissile into tile caudal fin where they become adults. Whereas those parasitic in the body cavity of the gold fish, 7 to 8 months the sutadults penetrate through muscle tissue into the caudal fin where they become adults. 1. Male subadults found in the body cavity of the Carassius auratus and gold fish, were larger than females, This is the first record of male subadults occurring in the fish host. 5. Among four different :drugs tested, most of all larvae died in 4 ppm of dipterex in 5 days. But no adults were harmed even in 6 ppm dipterex in 11 days.