• 한국산학기술학회논문지
• /
• 제12권8호
• /
• pp.3636-3643
• /
• 2011

연구실에서의 전기 사고를 방지하기 위하여 실시하는 전기 분야의 정기 점검에 대한 문제점을 파악하고 점검 항목에 대해 실제적으로 적용할 수 있는 퍼지 추론 시스템을 개발한다. 연구실의 전기 안전 환경을 중심으로 공통적으로 적용할 수 있는 점검 항목을 도출하고 연구실 전기 안전 관리에 부합한 연구실 정기 점검을 위한 전기 분야 표준 점검 리스트를 개발한다. 이러한 표준 점검 리스트를 이용하여 언어적 애매함을 포함할 수 있는 항목을 선정하고 이들 항목에 대해 소속 함수를 정의한다. 또한 안전 등급에 대해서도 소속 함수를 정의한다. 이러한 퍼지 변수들을 이용하여 If-Then 형식의 퍼지 규칙을 형성하고 퍼지 추론 엔진을 통해 퍼지 추론 시스템을 개발한다. 이를 통해 연구실의 전기 사고를 방지하기 위한 지능적이고 효율적인 점검 및 전기 안전을 지속적으로 관리함으로써 전기 사고를 미연에 방지할 수 있을 것이다.

• 한국콘텐츠학회논문지
• /
• 제11권4호
• /
• pp.92-100
• /
• 2011

본 논문에서는 새로운 변환 기법인 셀룰라 오토마타 변환을 이용한 워터마킹 방법과 기존의 DWT를 이용한 방법을 비교한다. 이 두 방법 모두 서로 상반되는 임의의 패턴 정보를 사용하여 워터마크 정보를 영상에 삽입한다. 셀룰라 오토마타 변환은 DWT와 달리 더 많은 정보 즉, 룰 번호, 초기 값, 격자 크기 등 다양한 초기값을 이용하여 기저함수를 생성하여 변환한다. DWT와 셀룰라 오토마타 변환을 이용하여 변환된 영상의 계수를 분석 및 비교한 후 워터마킹 성능을 비교한다. 모의실험에서는 워터마크 정보가 삽입된 영상에 대한 PSNR 및 정규화 상관계수를 이용하여 원영상과의 가시적인 동일성과 다양한 외부 공격에 대한 강인성을 비교한다. 셀룰라 오토마타 변환을 이용한 워터마킹 방법이 DWT를 이용한 방법보다 JPEG 압축, 미디언 필터, 크기 변환, 잘라내기 및 히스토그램 평활화 등 대부분의 공격에 대하여 강인함을 보여준다.

• 한국환경복원기술학회지
• /
• 제9권2호
• /
• pp.45-58
• /
• 2006

This study was aimed to propose the plan of creating a biotope reflecting an ecological education as well as its function as the habitats of amphibian in Namsan Urban Natural Park in Seoul. There were Cheonil mineral spring area which was located on the southern side of Namsan, wetlands which was already created on the east valley(800$m^2$) and a buffer area of the circumference(1,100$m^2$) as the biotope sites. Major fields of this study include a survey of the staus, a basic plan, a master plan; a survey of this site was focused on topography, water system, existing vegetation, wildbird, amphibian, trail; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 8 types; Pinus densiflora forest, Pinus densiflora planted area, Prunus sargentii-Quercus spp. forest, Pinus rigida forest, Robinia pseudoacacia forest, artificial green space, wetlands, south beltway. There were Pinus densiflora planted area and Prunus sargentii-Quercus spp. forest as major vegetations of this site. 14 species and 33 individuals of wildbirds appeared, Rana temporaria ornativentris and Hynobius leechi were investigated in the wetlands.In particular, habitats of amphibian were divided eco-zone, buffer-zone and restore-zone, and habitats and facilities which would be suitable for the characteristics of each space were planned. As a result, environment elements of good habitats including spawn wetlands of amphibian, harbor of amphibian, water plant of wetland, wild shrubs forest, ecological landscape forest, wetland observation trail, fence of wetland protection and ramp by pebble and log were created at the site. The amphibian biotope of Namsan is rated high as an important space for conserving biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.

• Journal of Chest Surgery
• /
• 제20권4호
• /
• pp.643-654
• /
• 1987

The effect of prostacyclin[PGI, ] on myocardial preservation during global ischemia was studied in the isolating working rabbit heart model. Forty hearts underwent a 15 minute period of retrograde nonworking perfusion with Krebs-Henseleit buffer solution [37*C] and were switched over to the working mode for 15 minutes. After baseline measurement of heart rate, peak aortic pressure, aortic flow, and coronary flow, all hearts were subjected to 60 minutes of ischemic arrest at 10*C induced with St. Thomas Hospital cardioplegic solution: Group I had single dose cardioplegia, Croup II double dose, Croup III oxygenated double dose, and Group IV single dose with PCI, infusion [10ng/min./gm heart weight]. Hearts were then revived with 15 minute period of nonworking reperfusion at normothermia, followed by 30 minutes of working perfusion. Repeat measurements of cardiac function were obtained and expressed as a percent of the preischemic baseline values. Oxygen content of arterial perfusate and coronary effluent was measured by designed time interval. Leakage of creatine kinase was determined during post-ischemic reperfusion period. Finally wet hearts were weighed and placed in 120*C oven for 36 hours for measurement of dry weight. In the PGI, treated group [IV], heart rate increased consistently throughout the period of reperfusion from 100*5.0% [p<0.001] to 107*6.2% [p<0.001]. The percent recovery of aortic flow showed 95*5.7% [p<0.001] at the first 3 minute and full recovery through the subsequent time. Coronary flow was augmented significantly in the 3 minute [96*6.2%, p<0.001] and then sustained above baseline values. Among the Croup I, II, and III, all hemodynamic values were significantly below preischemic levels. PGI2 relatively increased oxygen delivery [1.22*0.19ml/min, p<0.001] and myocardial oxygen consumption [0.90*0.13ml/min, p<0.001] during reperfusion period. Leakage of creatine kinase in the PGI2 group was 9.3*1.58IU/15min [p<0.001]. This was significantly lower than Group I [33.0*2.68 IU/15min]. The water content of PCI2 treated hearts [81*0.9%, p<0.001] was also lower than the other groups.

• The Korean Journal of Physiology and Pharmacology
• /
• 제13권4호
• /
• pp.321-326
• /
• 2009

The antioxidant effect of $CoQ_{10}$ on N-nitrosodiethylamine (NDEA)-induced oxidative stress was investigated in mice. Food intake and body weight were similar in both $CoQ_{10}$ and control groups during the 3-week experimental period. NDEA significantly increased the activities of typical marker enzymes of liver function (AST, ALT and ALP) both in control and $CoQ_{10}$ groups. However, the increase of plasma aminotransferase activity was significantly reduced in the $CoQ_{10}$ group. Lipid peroxidation in various tissues, such as heart, lung, liver, kidney, spleen and plasma, was significantly increased by NDEA, but this increase was significantly reduced by 100 mg/kg of $CoQ_{10}$. Superoxide dismutase activity increased significantly upon NDEA-induced oxidative stress in both the control and $CoQ_{10}$ groups with the effect being less in the $CoQ_{10}$ group. Catalase activity decreased significantly in both the control and $CoQ_{10}$ groups treated with NDEA, again with the effect being less in the $CoQ_{10}$ group. The lesser effect on superoxide dismutase and catalase in the NDEA-treated $CoQ_{10}$ group is indicative of the protective effect $CoQ_{10}$. Thus, $CoQ_{10}$ can offer useful protection against NDEA-induced oxidative stress.

• Fisheries and Aquatic Sciences
• /
• 제12권2호
• /
• pp.152-161
• /
• 2009

The largehead hairtail (Trichiurus lepturus) is one of the most common fisheries stocks in the East China Sea and the Yellow Sea. The species is caught using a variety of fishing tools, such as a stow net or a long line, as well as jigging and trawling. Scientific investigations have been conducted throughout the world to enable evidence-based estimations for the management and protection of the main fisheries biomass. For example, inshore and offshore hydro acoustic surveys are performed annually using bottom- and mid-water trawls around the Korean Peninsula. However, to date, no acoustic survey has been conducted to estimate fish size distribution, which is necessary to construct a data bank of target strength (TS) relative to fish species, length (L), and frequency. This study describes the frequency and length dependence of TS among fishes in Korean waters for the purpose of constructing such a TS data bank. TS measurements of the largehead hairtail were carried out in a water tank (L 5 m$\times$width 6 m$\times$ height 5 m) at frequencies of 50, 75, 120, and 200 kHz, using a tethering method. The average TS patterns were measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down) to $+45^{\circ}$ (head up) every $0.2^{\circ}$. The length conversion constant ($b_{20}$) was estimated under the assumption that TS is proportional to the square of the length. In addition, in situ TS measurements on live largehead hairtails were performed using a split beam echo sounder.

• The Korean Journal of Physiology and Pharmacology
• /
• 제20권6호
• /
• pp.621-628
• /
• 2016

Hypertension can be caused by various factors while the predominant causes include increase in body fluid volume and resistance in the circulatory system that elevate the blood pressure. Consumption of probiotics has been proven to attenuate hypertension; however, the effect is much strain-dependent. In this study, a newly isolated Lactobacillus casei (Lb. casei ) strain C1 was investigated for its antihypertensive properties in spontaneously hypertensive rats (SHR). Lactic acid bacteria (LAB) suspension of 11 log colony-forming unit (CFU) was given to SHR (SHR+LAB, n=8), and phosphate buffer saline (PBS) was given as a control in SHR (SHR, n=8) and in Wistar rats as sham (WIS, n=8). The treatment was given via oral gavage for 8 weeks. The results showed that the weekly systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP) and aortic reactivity function were remarkably improved after 8 weeks of bacterial administration in SHR+LAB. These effects were mostly attributed by restoration of wall tension and tensile stress following the bacterial treatment. Although not statistically significant, the level of malondialdehye (MDA) in SHR+LAB serum was found declining. Increased levels of glutathione (GSH) and nitric oxide (NO) in SHR+LAB serum suggested that the bacterium exerted vascular protection through antioxidative functions and relatively high NO level that induced vasodilation. Collectively, Lb. casei strain C1 is a promising alternative for hypertension improvement.

• 한국군사과학기술학회지
• /
• 제2권1호
• /
• pp.38-60
• /
• 1999

The main objective of this study is systemization of the technique of ROC quantification and optimization of baseline design by applying CE principle to the acquisition process of a weapon system. QFD and TOA techniques can be employed to a good working example of the conceptual design of a future main battle tank. In this paper, Product Planning Phase, the first phase of four QFD phases, is deployed in terms of eight steps including customer requirements and final product control characteristics. TOA is carried out considering only combat weight. In order to perform combat weight analysis and performance TOA, Preliminary Configuration Synthesis Methodology is used. Preliminary Configuration Synthesis Methodology employs the method of least squares and described linear equations of weight interrelation equation for each component of tank. As a result of QFD based upon the ROC, it was cleared that armor piercing power, main armament, type of ammunition, cruising range, combat weight, armor protection, power loading, threat detection and cost are primary factors influencing design and that combat weight is the most dominant one. The results of TOA based on the combat weight constraint show that 5100 lb reduction was required to satisfy the ROC. The baseline design of a future main battle tank is illustrated with assumption that all phases of QFD are employed to development and production process of subsystems, components, and parts of main battle tank. TOA is applied in iterative process between initial baseline design and ROC. The detailed design of each component is illustrated for a future main battle tank.

• 한국산학기술학회논문지
• /
• 제17권11호
• /
• pp.196-201
• /
• 2016

디지털 워터마킹은 디지털 미디어 내부에 정보를 숨기기 위해 사용하는 기술로, 디지털 워터마킹 기술은 Robust 워터마킹 기술과 Fragile 워터마킹 기술로 분류할 수 있다. Robust 워터마킹 기술은 일반적으로 저작권을 보호하기 위한 목적으로 사용되고 있으며, Fragile 워터마킹 기술은 영상에 대한 인증과 무결성을 검증하기 위한 목적으로 사용된다. 따라서 Fragile 워터마킹 기술에서는 워터마킹 된 영상에 대해 작은 변형이라도 발생 하였을 경우 삽입된 워터마크는 쉽게 부수어져야 되는 특성을 가지고 있어야 한다. 본 논문에서는 공간 영역에서 영상의 변형 검출을 위한 효과적인 Fragile 워터마킹 방법을 제안하였으며, 본 논문에서 제안한 방법에서는 해쉬 코드와 대칭키 암호를 사용하였다. 제안 방법에서는 원 영상을 작은 크기로 구성된 여러 블록들로 분할한 후 워터마크를 삽입하기 때문에 cut and paste와 같은 공격에 취약하지 않은 특징을 가지고 있으며, 변형 검출을 위하여 워터마크가 삽입된 영상에 대해 전체 블록을 검사하지 않고도 변형이 발생된 부분만을 빠르게 검출할 수 있는 장점이 있다.

• 한국철도학회논문집
• /
• 제15권1호
• /
• pp.29-36
• /
• 2012

본 연구는 무선통신기반 열차제어시스템의 ATP 기능을 차상장치와 지상장치에 배치하고 이를 검증하기 위한 ATP시뮬레이터 개발과 ATP알고리즘 검증을 포함한다. 무선통신기술을 열차제어에 적용하면 열차제어 시스템을 단순화하고 실시간 열차위치정보를 활용하여 열차운행의 안전성을 높이는 특징이 있다. 특히 ATP 지상장치와 차상장치에서 vital기능을 처리할 수 있다. 이 같은 vital기능을 어디에 배치하는 가에 따라서 인터페이스내용이 상이한 서로 다른 시스템이 구현된다. 따라서 지상과 차상에 vital 기능을 배치하는 것에 따른 특징을 도출하고, 이것에 의해서 영향을 받는 인터페이스 내용을 확인하는 것이 필요하다. 본 논문에서는 ATP 지상장치에 열차이동권한과 열차속도제한 등의 기능을 배치하였고, 전동기를 직접 구동하여 실시간 열차위치정보를 생성하는 ATP시뮬레이터를 개발하였고, 본 시뮬레이터를 사용하여 ATP 알고리즘을 검증하였다. ATP 알고리즘을 검증하기 위한 적절한 모의환경을 확인하였고, ATP 기능에 영향을 주는 주요 인자를 확인하였다.