• Tunnel and Underground Space
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• v.19 no.4
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• pp.348-354
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• 2009

Slug test is a common characterization method that estimates aquifer hydraulic conductivity rapidly and economically. To characterize the hydraulic property near the borehole YS-4 in the Korea Atomic Energy Research Institute (KAERI) site, slug tests were performed, and oscillatory hydraulic responses were observed. We analyzed the observations with the modified Hvorslev and Bouwer&Rice methods considering the casing inertia, and then the results were compared with those from the general Hvorslev and Bouwer&Rice methods. The estimated hydraulic conductivities from the modified methods are ranged from $4.85{\times}10^{-6}$ to $5.44{\times}10^{-6}$ m/sec, but those from the general ones are ranged from $3.10{\times}10^{-6}$ to $3.63{\times}10^{-5}$ m/s, which shows that the oscillatory responses should be analyzed with consideration of the flowing water inertia effect.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.129-135
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• 2003

Optical fiber has many advantages, such as high reliability, long lifetime, immunity to the electromagnetic interference, high speed response and low cost. In this study, we proposed and developed an optical fiber impact and pressure sensor for prevention of accident which occurs in the automatic system or auto door. The principle of the sensor is to detect different optical intensity caused by variation of a speckle pattern due to the external perturbation. Speckle pattern appears at the end of a multimode fiber in which coherent beam propagates. The fabricated sensor in this study was tested. As a result of experiments, amplitude of the output signal isn't linear, but it has sufficient sensitivity for a sensor. Moreover, we can control sensitivity of the sensor by an amplifier at receiver. It has several advantages which are ability of detection at all point on the multimode fiber, large sensitive area, and many application areas for a sensing impact and pressure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1077-1082
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• 2001

기존의 타이어를 사용한 중량충격음에 대한 차음성능 평가방법의 타당성을 살펴보기 위하여 청감실험에 의한 감성적 반응결과와 L등급 및 Leq에 의한 평가 결과를 비교 분석하였다. 동일한 바닥충격원에 대한 분석결과 L등급평가 보다 Leq에 의한 평가가 청감실험의 반응에 잘 대응하는 것으로 나타났다. 또한, Zwicker parameters 중 Loudness와 Unbiased Annoyance는 청감실험과 가장 유사한 경향을 보였다.

• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.584-593
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• 2023

This study attempted to develop repetitive impact sources similar to real-life floor impact noise and to find an assessment approach corresponding to this new impact source. The necessity for the development of the new impact source arises from the fact that issues related to floor impact noise in actual residential buildings mainly stem from children running. However, the standard impact sources which have been used for measuring and evaluating floor impact noise are of single-impulse type, which differs from the actual problematic impact sources. The study encompassed 18 evaluation items, and the results suggest that items applicable for assessing floor impact noise include psychological effects (annoying, becoming angry), disturbances to daily life (interference with sleep, disruption of relaxation), and physiological effects (elevated blood pressure). These items can be employed individually and, depending on the type of evaluation for floor impact noise, can be selectively utilized. By doing so, more comprehensive evaluations of auditory experiments in laboratories or assessments of residential noise in living environments related to floor impact noise could be conducted.

• The Korean Journal of Rheology
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• v.5 no.2
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• pp.170-179
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• 1993

결정성 고분자/비결정성 고분자/충격보강재의 조합으로 이루어진 열가소성 삼성분계 블렌드의 미세구조 조절이 기계적 및 열적 거시물성에 미치는 영향을 살펴보았다. 결정성 고분자로는 나일론6를 비결정성 고분자로는 변성폴리페닐린 옥사이드(PPO)를 충격 보강재 로는 스티렌-에틸렌부틸렌-스티렌(SEBS) 삼중블록 공중합체를 사용하였고 비상용인 나일 론6와 변성 PPO 사이의 상용화를 위해 반능 상용화(reactive compatibilization)방법을 사용 하였다. 반응 사용화에 사용된 반응기로는 나일론의 말단기에 있는 친핵성기인 아민기와 반 응성이 높은 친전자성기인 무수말레인산(MAH)을 충격보강 고부 SEBS에 그라프트시켜 충 격보강 고무내의 SEBS-MAH의 함량을 증가시킴에 따라 처음에 PPO 분산상에 있던 고무 가 나일론 연속상으로 이동하는 현상을 관찰하였다. 이러한 충격보강 고부의 SEBS-MAH 함량 증가에 의한 PPO 분산상에서 나일론상으로의 이동이 내충격성의 향상 및 내열성의 저 하와 밀접한 관계가 있다는 것을 알았다.

• Journal of Life Science
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• v.19 no.12
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• pp.1705-1711
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• 2009

Carcinoma cells that had acquired resistance to a chemotherapeutic drug often show cross-resistance to various other cytotoxic drugs. In the present study, we explored the effect of heat shock in cisplatin-resistant gastric cancer cells SNU601/Cis2 to figure out the efficacy of hyperthermia in drug-resistant carcinoma. While SNU601/WT cells showed a high-sensitivity response to heat shock by dying through apoptosis, SNU601/Cis2 cells were considerably resistant to mild heat shock, but died by necrosis upon treatment with harsh heat shock. The occurrence of necrosis in SNU601/Cis2 cells was linked to the suppression of both JNK1/2 activation and HSP27 induction in response to heat shock. Since necrosis is closely associated with tumor malignancy and poor prognosis through inflammatory responses, our result suggests that hyperthermic treatment should be carefully applied when it is combined with chemotherapy.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.377-382
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• 1992

The responses of C. jejuni to ethanol shock were studied for their survival. synthesis of ethanol shock proteins, and increased survival at higher concentration of ethanol upon prior treatments of ethanol. When C. jejuni were shocked with ethanol at 1. 3. and 5% for 60. 30 and 10 minutes, respectively. those cells synthesized the ethanol shock proteins of 90, 66, 60, 45, and 24 kd in molecular weight. When the C. ,jejuni shocked with 1 and 3% ethanol were exposed to 3 and 5% ethanol for 30 minutes. their survival rates were increased by $10^1$~$10^2$ as compared with those of the cells without ethanol-shock. In the same way. C. ,jejuni shocked with 5% ethanol for 10 minutes :.bowed about 102 times higher survival rates than the cells without ethanol-shock. This result suggests that C jejuni shocked with I-5% ethanol for 10-30 minutes synthesized five kinds of ethanol shock proteins. and that the shock proteins contributed to increase ethanol tolerance for their survival at the higher concentrations of ethanol.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.217-240
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• 2011

In this study, vector autoregressive and vector error correction models in the short-run dynamics are considered to analyze the effect of the changes in international crude oil prices on Baltic dry index, Baltic Capesize index and Baltic Panamax index, and the intercorrelations between Capesize and Panamax prices, respectively. First, using the vector autoregressive model, the changes in international crude oil price have a statistically significant positive effect for Capesize at lag 1, for Panamax a significant negative effect at lag 3 and a significant positive effect for Baltic dry index at lag 1. From the impulse response analysis, the international crude oil price causes Baltic dry index to increase in the sort-run and the effect converges on the mean after 3 months. Second, using the vector error correction model, the empirical results for the spillover effects between Capesize and Panamax markets provide that in the case of the deviation from a long-run equilibrium the Panamax price is adjusted toward decreasing. The increases in freight rates of the Capesize market at lag 1 lead to increase the freight rates in Panamax market at present. The Panamax responses from the Capesize shocks increase rapidly for 3 months and the effect converges on the mean after 5 months. The Capesize responses from the Panamax shocks are relatively small, and increase weakly for 3 months and the effect disappears thereafter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.97-98
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• 2010

• Journal of fish pathology
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• v.12 no.2
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• pp.89-99
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• 1999

New sixteen heat shock proteins (Hsps) and ten ethanol shock proteins were appeared on the analysis with SDS-PAGE when cultivation temperature for the Vibrio vulnifrcus ATCC 27562 strain was shifted-up to $42^{\circ}C$ from $30^{\circ}C$ for 20 mins and treated with of 6% ethanol for 10 mins, respectively. Even the induction of thermotolerance in V. vulnificus was coincided with the induction of Hsps if the pre-shock was adjusted to thermal temperature. Outer membrane proteins (OMPs) that were purified from the membrane of cells after heat shock showed more immunodominant pattern to the immunized rabbit anti-V. vulnificus O serum in enzyme-linked immunosorbent assay (ELISA). On the western immunoblot analysis it was confirmed that both 62 kDa IMP and 69 kDa OMP in the Hsps and 48 kDa IMP a major OMP in the ethanol shock proteins were reacted with rabbit anti-V. vulnificus O sera. Agglutination titer of the heat shocked V. vulnificus with rabbit anti-V. vulnificus O serum was higher than that of the untreated bacteria.