• JSTS:Journal of Semiconductor Technology and Science
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• 제15권4호
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• pp.445-453
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• 2015

A fully integrated cost-effective and low-power single chip Lithium-Ion (Li-Ion) battery protection IC (BPIC) for portable devices is presented. The control unit of the battery protection system and the MOSFET switches are integrated in a single package to protect the battery from over-charge, over-discharge, and over-current. The proposed BPIC enters into low-power standby mode when the battery becomes over-discharged. A new auto release function (ARF) is adopted to release the BPIC from standby mode and safely return it to normal operation mode. A new delay shorten mode (DSM) is also proposed to reduce the test time without increasing pin counts. The BPIC implemented in a $0.18-{\mu}m$ CMOS process occupies an area of $750{\mu}m{\times}610{\mu}m$. With DSM enabled, the measured test time is dramatically reduced from 56.82 s to 0.15 s. The BPIC chip consumes $3{\mu}A$ under normal operating conditions and $0.45{\mu}A$ under standby mode.

• 한국환경과학회지
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• 제13권7호
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• pp.675-680
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• 2004

This study was conducted to remove organics and nutrients using 2 stage intermittent aeration reactor. First reactor, using suspended microbial growth in intermittent aeration instead of anaerobic reactor in the typical BNR process, used minimum carbon source to release P, and it was possible to reduce ammonia loading going to second reactor. In the second reactor, using moving media intermittent aeration, it was effective to reduce nitrate in non-aeration time by attached microorganisms having long retention time. In aeration time, nitrification and P uptake were taken place simultaneously. From the experiment, two major results were as follows. First, the removal of organics was more than 90%, and optimum aeration/non-aeration time ratio for organic removal was corresponded with aeration/non-aeration time ratio for nitrogen removal. Second, in the first reactor, optimum aeration/non-aeration time ratio was 15/75 (min.) because it was necessary to maintain 75 min. of non-aeration time to suppress of impediment of return nitrate and to lead release of phosphate. In the second reactor, optimum aeration/non-aeration time ratio was 45/90 (min.).

• Journal of Korean Neurosurgical Society
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• 제29권3호
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• pp.372-378
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• 2000

The carpal tunnel syndrome is one of the most common entrapment neuropathy. Surgical treatments consist of conventional open technique, alternative technique using retinaculatome, and endoscopic surgery. This study compares the outcomes of surgical treatment of carpal tunnel syndrome following conventional versus endoscopic release. The authors reviewed 56 cases of 33 patients with carpal tunnel syndrome treated surgically in our institute from January 1991 to May 1998. The follow-up evaluation was possible in 36 cases of 20 patients who had conventional release and in 11 cases of 7 patients with endoscopic release. The following parameters were evaluated for comparison : improvement of symptom, return to normal work, recovery of strength of grip and pinch, rate of complication, follow-up electrophysiologic finding. Compared with open decompression, the group of endoscopic decompression needed significantly less time to go back to work(p<0.001). Also strength of grip and pinch improved faster in the group of endoscopic decompression as well, compared with open decompression(p<0.05). These results indicate that endoscopic procedure is an excellent, minimally invasive method to treat carpal tunnel syndrome, performed by surgeons who are fully aware of the anatomy.

• Journal of Chest Surgery
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• 제22권4호
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• pp.580-588
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• 1989

The potential for enhancing myocardial protection by adding high-energy phosphate to cardioplegic solutions [St. Thomas Hospital solution] was investigated in a rat heart model of cardiopulmonary bypass and ischemic arrest. Creatine phosphate was evaluated as an additive to the St. Thomas Hospital cardioplegic solution. Creatine phosphate 10.0 mmol/L as the optimal concentration which improved recovery of aortic flow and cardiac output after a 30 minute period of normothermic [37oC] ischemic arrest. In comparing mechanical function in both groups the mean postischemic recoveries of aortic flow, cardiac output, stroke volume and stroke work [expressed as a percentage of its preischemic control] were significantly greater in STH-CP group than in CP- free control group. In addition to improving function and decreasing CK release, CP reduced reperfusion arrhythmias significantly decreasing the time between cross-clamp removal and return to regular rhythm from 81.8 * 13.9 [sec] in CP-free group to 35.9 * 6.8 [sec] in CP group [P< 0.05] so, exogenous CP exerts potent protective and antiarrhythmic effects when added to the St. Thomas Hospital cardioplegic solution. However, the mechanism of action remains to be elucidated.

• 물과 미래
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• 제19권4호
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• pp.339-346
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• 1986

소양강댐 및 충\ulcorner댐의 실시간 홍수조절 모형을 개발하기 위한 방법으로 Min-Max Dynamic Programming에 의한 최적화 기법을 사용하였다. 최적화 모형의 목적 함수로서는 각 댐의 최대 방류량을 최소화하도록 하였으며, 각 저수지 및 하도의 특성에 따른 제약 조건을 고려하였다. 개발된 단일 저수지 운영 모형에 의한 홍수조절 효과를 평가하는 척도로서 조절율과 이용율을 사용하였다. Technical ROM, Rigid ROM 및 Linear Decision rule과 같은 simulation 모형에 의한 조절 효과와 비교한 결과 모든 빈도에 대하여 DP에 의한 최적화 방법이 더 좋은 것으로 나타났다.

• 대한산업공학회지
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• 제34권4호
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• pp.398-407
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• 2008

We consider a product recovery system that a single product is stocked in order to meet a demand from customers who may return products after usage. This paper addresses a problem of when to release a procurement process to replenish serviceable inventory and how many new products to procure. The structure of the optimal procurement policy is examined and numerically identified as a monotonic threshold curve. A numerical procedure is presented to jointly find the optimal procurement order size, optimal procurement policy, and optimal discounted profit. Sensitivity analysis also indicates that these optimal performance measurements have monotonic properties with respect to system parameters.

• 한국해양학회지:바다
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• 제12권2호
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• pp.73-80
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• 2007

우리나라의 방류사업은 1913년의 함경남도 고원에서 최초로 시작하여 1969년 이후 한미기술 협력에 따라 부화장이 설립되고 정부의 연어 자원조성을 위한 계속된 투자로 1980년대 초부터 서서히 소상량이 증가하기 시작하여 1999년에는 2,000만 마리까지 방류함으로써 명실상부하게 우리나라에서 자원조성에 가장 성공한 사례로 꼽히게 되었다. 방류지역은 처음에는 인공부화장이 위치한 지역을 중심으로 방류하였으나, 생산량 증가에 따라 강원도 고성군 명파천에서부터 경상남도 밀양강까지 방류하게 되었으며, 최근에는 전방 DMZ, 전라남도 섬진강 및 북강원도에도 방류함으로서 방류지역을 점차 확대해 나가고 있다. 회귀율은 1973년에 0.06%에서 1990년부터 바다연어를 포획하면서 1.57%의 회귀율을 보인 후 계속 1%이상을 유지하였다. 그 이후 1999년에 0.72%로 다소 떨어진 후 2000년에는 바다의 환경변화로 인하여 0.10%로 회귀율이 급격하게 감소하여 최근까지 0.22%의 회귀율을 보이고 있다. 연어 자원증강을 위해서는 건강한 치어 생산은 물론 바다연어 및 미성숙 친어의 축양시설 개발, 방류하천의 중간 육성장 개발, 치어 및 친어의 회유로 구명 등 적극적인 연구가 이루어져야 하며, 정부에서는 방류사업에 보다 많은 관심과 예산을 투입하여야할 것으로 사료된다.

• Macromolecular Research
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• 제11권4호
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• pp.207-223
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• 2003

For last five years, we are developing the novel local drug delivery devices using biodegradable polymers, especially polylactide (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) due to its relatively good biocompatibility, easily controlled biodegradability, good processability and only FDA approved synthetic degradable polymers. The relationship between various kinds of drug [water soluble small molecule drugs: gentamicin sulfate (GS), fentanyl citrate (FC), BCNU, azidothymidine (AZT), pamidronate (ADP), $1,25(OH)_2$ vitamin $D_3$, water insoluble small molecule drugs: fentanyl, ipriflavone (IP) and nifedipine, and water soluble large peptide molecule drug: nerve growth factor (NGF), and Japanese encephalitis virus (JEV)], different types of geometrical devices [microspheres (MSs), microcapsule, nanoparticle, wafers, pellet, beads, multiple-layered beads, implants, fiber, scaffolds, and films], and pharmacological activity are proposed and discussed for the application of pharmaceutics and tissue engineering. Also, local drug delivery devices proposed in this work are introduced in view of preparation method, drug release behavior, biocompatibility, pharmacological effect, and animal studies. In conclusion, we can control the drug release profiles varying with the preparation, formulation and geometrical parameters. Moreover, any types of drug were successfully applicable to achieve linear sustained release from short period ($1{\sim}3$ days) to long period (over 2 months). It is very important to design a suitable formulation for the wanting period of bioactive molecules loaded in biodegradable polymers for the local delivery of drug. The drug release is affected by many factors such as hydrophilicity of drug, electric charge of drug, drug loading amount, polymer molecular weight, the monomer composition, the size of implants, the applied fabrication techniques, and so on. It is well known that the commercialization of new drug needs a lot of cost of money (average: over 10 million US dollar per one drug) and time (average: above 9 years) whereas the development of DDS and high effective generic drug might be need relatively low investment with a short time period. Also, one core technology of DDS can be applicable to many drugs for the market needs. From these reasons, the DDS research on potent generic drugs might be suitable for less risk and high return.

• 한국환경과학회지
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• 제29권9호
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• pp.885-905
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• 2020

This study described the characteristics of the upstream migration of salmon (Chum salmon, Oncorhynchus keta) along Yeon-gok Stream in the eastern coastal region of Korea from October 24 to November 9, 2018 using radio tag and data storage tag loggers for the detection of the locations of tagged salmon and measurement of water temperature. Tracking experiments were conducted and classified into four types (case 1 to case 4) depending on the release time and the number of salmon tracked. Experiments from case 1 to case 3 were classified depending on the number of salmon tracked into cases in which a single tagged salmon was tracked (case 1), a pair of tagged salmon was tracked (case 2), and salmon were tracked by different sex ratios (case 3). Experiments from cases 1 to 3 were conducted between 10 AM and 1 PM, and case 4 was conducted after 3:30 PM. Salmon moved and spawned in the downstream region of the Yeon-gok, where water temperature is higher than in other rivers and salmon return in Canada, Russia, Japan, and the U.S.A. Most of the radio-tagged salmon swam in deep and shaded areas during the day but actively moved upstream close to sunset, regardless of the release time. Females showed relatively more active movements than males during upstream migration.

• 한국지반환경공학회 논문집
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• 제14권11호
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• pp.55-63
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• 2013

농업용 저수지의 경우, 인위적인 홍수조절 기능이 없어 홍수 발생 시 급격한 저수지 수위상승에 따른 월류로 인해 제체의 파괴위험이 높고, 예 경보 없이 상류에서 유입되는 홍수량을 그대로 방류하여 하류 지역에 농경지 침수 등 홍수피해가 발생할 위험성이 높다. 본 연구에서는 경상북도 상주시에 위치한 지평저수지를 대상으로 수문분석을 실시하여 설계홍수량(200년 빈도의 1.2배)을 산정하고, 저수지 추적기법을 통해 기존 여수로와 사이펀 여수로 설치에 따른 저수지 홍수조절능력을 비교 분석하여 사이펀 여수로의 홍수조절 효과를 분석하였다. 그 결과, 지평저수지의 설계홍수량은 $284.3m^3/s$, 로 산정되었으며, 사이펀 여수로의 사전방류를 통해 수위가 약 40cm 정도 하강하고 방류량은 $91m^3/s$, 정도 감소하는 것으로 분석되었다.