• 마이크로전자및패키징학회지
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• 제23권4호
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• pp.69-77
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• 2016

We propose nano-scale Cu direct bonding technology using ultra-high density Cu nano-pillar (CNP) with for high stacking yield exascale 2.5D/3D integration. We clarified the joining mechanism of nano-scale Cu direct bonding using CNP. Nano-scale Cu pillar easily bond with Cu electrode by re-crystallization of CNP due to the solid phase diffusion and by morphology change of CNP to minimize interfacial energy at relatively lower temperature and pressure compared to conventional micro-scale Cu direct bonding. We confirmed for the first time that 4.3 million electrodes per die are successfully connected in series with the joining yield of 100%. The joining resistance of CNP bundle with $80{\mu}m$ height is around 30 m for each pair of $10{\mu}m$ dia. electrode. Capacitance value of CNP bundle with $3{\mu}m$ length and $80{\mu}m$ height is around 0.6fF. Eye-diagram pattern shows no degradation even at 10Gbps data rate after the lamination of anisotropic conductive film.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.386-394
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• 2007

Due to the transportability problems, long rail shall be from base rail unit, which is normally 100m for regular rail and 300m for high speed rail. After these rail units are transported from the fabricator to the site, the field weld would be performed.axial stresses in the long rail is mainly from the temperature differences at various locations the long rail. Also the gaps between each welds cause secondary axial stresses in the rail. In addition to these, re-welds the fractured rails, rail buckling, irregular rail vibration, rail twist also result innonuniform axial stresses in the rail. To obtain the rail buckling stability, the rail stresses shall be released due to the resetting of CWR. Traditionally two resetting of CWR methods have been applied, the one is rail heater and the other is rail tenser. these methods, the latter has been recommended because it has less limitation in the rail length and it is easier to minimized the force differences. But even in this method, the calculation is cumbersome and is not easy to find out the rail stress distribution itself.refined methodsxial stress resetting in the long rail is studied and this study be easily applied in the real construction. From this approach, more rational rail maintenance system can be expected.

• BMB Reports
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• 제38권3호
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• pp.259-265
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• 2005

Proteins must fold into their correct three-dimensional conformation in order to attain their biological function. Conversely, protein aggregation and misfolding are primary contributors to many devastating human diseases, such as prion-mediated infections, Alzheimer's disease, type II diabetes and cystic fibrosis. While the native conformation of a polypeptide is encoded within its primary amino acid sequence and is sufficient for protein folding in vitro, the situation in vivo is more complex. Inside the cell, proteins are synthesized or folded continuously; a process that is greatly assisted by molecular chaperones. Molecular chaperones re a group of structurally diverse and mechanistically distinct proteins that either promote folding or prevent the aggregation of other proteins. With our increasing understanding of the proteome, it is becoming clear that the number of proteins that can be classified as molecular chaperones is increasing steadily. Many of these proteins have novel but essential cellular functions that differ from that of more 'conventional' chaperones, such as Hsp70 and the GroE system. This review focuses on the emerging role of molecular chaperones in protein quality control, i.e. the mechanism that rids the cell of misfolded or incompletely synthesized polypeptides that otherwise would interfere with normal cellular function.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1980년도 학술대회지
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• pp.59-69
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• 1980

A new HPLC-method for separation and quantitative determination of ginsenosides in Panax ginseng, Panax quinquefolium and in pharmaceutical drug preparations is elaborated. A reversed-phase-system with ${\mu}Bondapak\;C_{18}$ column (3.9 mm $I.D.{\times}30\;cm$) using acetonitrile-water (30:70) 2 ml/min and acetonitrile-water (18:82) 4 ml/min is suitable for the base-line separation of $Rb_1,\;Rb_2,\;Rc,\;Rd,\;Rf,\;Rg_2,\;respectively\;Re,\;Rg_1$ in 30 minutes. The ginsenosides are directly detected at 203 nm (without derivatization) with the LC-55 or LC-75 spectrophotometer (Perkin-Elmer) at $100\%$ transmission. Detection limit is 300 ng at a signal-to-noise ratio of 10:1. The ginsenosides-peak identification is carried out with HPTLC (high performance thin layer chromatography), with MIR-IR (multiple internal reflection-IR-spectros-copy) and with FD-MS (field desorption mass spectrometry). The calibration curve of each ginsenoside has a correlation coefficient very near to 1. Relative standard deviation for quantitative determinations depends upon the amount of ginsenosides and is approximately 1\%$ for ginsenoside contents of 1\%$. This method is adaptable for routine analysis in quality control laboratories.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2660-2669
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• 2022

The attractiveness for weapons usage of the proposed fuel cycle for the PT-SCWR was evaluated in this study using the Figure-of-Merit methodology. It was compared to the attractiveness of other fuel cycles namely, Low Enriched Uranium (LEU), U/Th, Re-enriched Reprocessed Uranium (RepU), and Pu/Th/U. The optimal content of natural uranium, which can be added to Pu/Th to render the produced U-233 unattractive, was found to be 9%. A ranking system to compare the attractiveness of the various fuel cycles is proposed. RepU was found to be the most proliferation resistant fuel cycle for the first 100 years,while, the least proliferation resistant fuel cycle was the originally proposed Pu/Th one. The reactivity feedback coefficients were calculated for all proposed fuel cycles. All studied reactivity coefficients have the same sign implying that all the fuel cycles will behave neutronically in a similar way. The Pu/Th/U fuel was found to have the most negative value of the Coolant Void Reactivity which will help to restore the core to a safe status faster in case of a loss-of-coolant accident. The fuel and moderator temperature coefficients did not show significant differences between the fuels studied.

• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.35-44
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• 2022

Immersed boundary-Lattice Boltzmann Method (IB-LBM) is used for the analysis of flow over the circular cylinder in the concept of fluid-structure interaction analysis (FSI). Recently, IB-LBM has shown the enormous possibility for the application of various biomedical engineering fields, such as the movement of a human body or the behavior of the blood cells and/or particle-based drug delivery system in blood vessels. In order for the numerical analysis of the interaction between fluid and solid object, immersed boundary method and lattice Boltzmann method are coupled to analyze the flow over a cylinder for low Reynolds laminar flow (Re=10, 20, 40 and 100) with Zhu-He boundary condition at the boundary. With the developed IB-LBM, the flow around the cylinder in the uniform flow is analyzed for the laminar flow and the drag and lift coefficients and recirculation length are compared to the previous results.

• 한국생활환경학회지
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• 제16권2호
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• pp.89-100
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• 2009

본 연구는 최대하 부하 트래드밀 운동과 간헐적 부위별 인체 냉각 시 심부와 말초 부위의 동적 체온조절을 관찰하기 위해 고안되었다. 이를 위해 총 다섯명의 남자 피험자가 세 가지 실험 조건, 머리와 손 냉각 조건(HH cooling), 다리 냉각 조건(Leg Cooling), 냉각하지 않는 대조군(Control)에 참여하였고, 모든 실험은 기온 24±1℃와 습도 50±5%RH로 유지되는 인공기후실에서 수행되었다. 피험자들은80%HR_max의 트래드밀 운동과 이어지는 회복 스케쥴을 두 번 반복하였고, 인체 부위별 냉각은 15℃의 물이 순환하는 액체 냉각모자, 장갑, 다리를 덮는 형태의 담요를 이용하여 회복 시에만 적용되었다. 본 연구 결과, (1) 직장온도(T_re)는 세 조건 간에 유의한 차이를 보이지 않았다; (2) 피부온도는 부위별로 특징되어지는 다양한 체온조절 현상을 보였다. 특히, 운동의 시작 시점에서 보이는 피부온도의 초기 하강은 주로 가슴, 넓적다리, 종아리, 손가락 피부 온도에서 관찰되었으며, 이 중 손가락 온도(T_fing)에서의 초기 하강 현상은 매우 현저했다. (3) 피부 온도가 초기 하강을 보이는 동안 T_re는 점점 증가했다. (4) 두 번째 운동 시작 시 T_fing에서의 초기 하강 규모는 Control 조건에서 평균 4.8℃, HH cooling 조건에서는 5.1℃, Leg cooling 조건에서는 3.4℃로, 통계적으로 유의한 차이를 보였다(p<0.05). 초기 하강 현상을 보인 시간은 Control 조건에서 평균 8.1분으로 HH cooling 조건에서는 7.9분, Leg cooling 조건에서는 6.3분보다 길었으나 통계적 차이는 발견되지 않았다. 결론적으로, 트래드밀 운동의 개시기에 관찰된 피부온도 하강 현상은 인체 심부의 온열 상태의 진행과는 반대되므로, 비 온열적 요인을 반영한다. 특히, T_fing에서 초기 하강의 규모는 인체 부위별 냉각에 의해 영향을 받았다. 따라서, 말초 부위의 피부온도 하강 현상은 운동 중 피부면의 온열 상태 예측 시 주의깊게 고려되어져야 한다.

• 대한기계학회논문집B
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• 제30권2호
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• pp.110-116
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• 2006

A syringe pump or a device using high electric voltage has been used for controlling flows inside a LOC (lab-on-a-chip). Compared to LOC, however, these microfluidic devices are large and heavy that they are burdensome for a portable ${\mu}-TAS$ (micro total analysis system). In this study, a new flow control technique employing pressure regulators and pressure chambers was developed. This technique utilizes compressed air to control the micro-scale flow inside a LOC, instead of a mechanical actuator or an electric power supply. The pressure regulator controls the output air pressure by adjusting the variable resistor attached. We checked the feasibility of this system by measuring the flow rate inside a capillary tube of $100{\mu}m$ diameter in the Re numbers ranged from 0.5 to 50. In addition, the performance of this flow control system was compared with that of a conventional syringe pump. The developed flow control system was found to show superior performance, compared with the syringe pump. It maintains automatically the: air pressure inside a pressure chamber whether the flow inside the capillary tube is on or off. Since the flow rate is nearly proportional to the resistance, we can control flow in multiple microchannels precisely. However, the syringe pump shows large variation of flow rate when the fluid flow is blocked in the microchannel.

• 한국수산과학회지
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• 제33권4호
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• pp.348-355
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• 2000

발파작업으로 인한 소음 레벨과 시험어의 행동과의 관계를 구명하기 위하여 1997년 충북 제천시에 있는 충주호의 가두리 양식장에서, 발파에 따른 수중소음 레벨을 측정하고, 그 때의 시험어(향어, 체장 28cm)의 행동을 바이오텔레메트리 기법으로 3차원으로 추적한 결과를 요약하면 다음과 같다. 1. 소음원으로부터 400m 거리에서 측정한 발파 중의 수중소음 레벨은 발파 전에 비하여 $40dB (re\;1\;{\mu}Pa)$ 증가하였다. 발파작업 소음의 탁월주파수는 $75{\~}100\;Hz$이었고 파워 스펙트럼 레벨의 증가량은 $22.9{\~}35.3 dB$이었다. 2. 소음원으로부터 350m 거리에서 측정한 시험 발파에 의한 수중소음 레벨은 발파가 없을 때에 비하여 평균 49.5dB 증가하였다. 3. 발파 후부터 1시간까지는 유영 범위가 발파 전에 비하여 감소하였으며, 그 이후에는 유영 범위나 행동이 발파 직전과 비슷한 상태를 나타내었다. 4. 발파 전에는 주로 중층이나 표층에 머물렀던 시험어가 1차 발파 및 2차 발파가 있었던 경과시간 26분과 34분 이후 46분경까지는 다른 시간대에 비하여 저층으로 도피해 있는 행동이 많이 나타났으며, 그 이후부터는 표층으로 부상하여 유영하는 경우가 많은 것으로 나타났다. 5. 발파전, 발파 중, 발파 후의 시험어의 평균 유영 속도는 각각 0.33 m/sec (체장의 1.2배), 0.52m1sec (체장의 1.9배), 0.29m/sec (체장의 1.0배)이었고, 발파 중의 유영속도는 발파작업이 없을 때에 비하여 약 1.6배 빠르게 나타났다. 따라서, 이 연구에서 측정한 발파작업 소음은 가두리 양식장에서 사육하고 있던 시험어에 대하여 생태적으로 좋지 않은 영향을 미칠 수 있을 것으로 사료된다.

• 한국토양비료학회지
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• 제44권3호
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• pp.434-441
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• 2011

축산농가에서 소규모로 발생하는 고농도의 질소와 인을 함유한 축산폐수의 처리효율을 극대화시키기 위해 수생식물여과조-활성슬러지조-인공습지로 구성된 축산폐수처리 시스템에서 축산폐수 재주입 비율별 및 주입방법별 수처리 효율을 조사하였다. 축산폐수의 재주입 비율별에 따른 처리효율을 조사한 결과 COD, SS, T-N 및 T-P 처리효율은 30% < 70% ${\leq}$ 100%의 순으로 재주입 비율이 증가함에 따라 오염물질의 처리효율이 점점 증가하는 경향이었다. 또한, 주입방법에 따른 COD, SS, T-N 및 T-P의 처리효율을 조사한 결과 1차 및 2차 처리조까지는 연속적 주입이 간헐적 주입에 비해 약간 높은 처리효율을 보였으나, 3차 처리조 부터는 비슷한 처리효율을 보였으며, 방류수 중COD, SS, T-N 및 T-P의 처리효율은 연속주입방법이 각각 99.5, 99.8, 99.0 및 99.8%로 간헐주입에 비해 약간 높았다. 이들 결과를 미루어 볼 때, 본 현장 인공습지 축산 폐수처리장에서 은 적합한 축산폐수의 재주입 비율과 주입방법을 선정한다면 질소 및 인 처리효율을 향상 시킬 수 있을 것으로 판단된다.