• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 춘계학술대회
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• pp.29-32
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• 2019

정보통신기술의 발전으로 인하여 선박 내 시스템 간 또는 선박과 육상 시설 간의 정보 교환 및 통신이 용이하게 되어 업무 효율이 향상되고 있다. 그러나 이러한 회사와 선박의 업무 환경의 변화는 회사 및 선박의 시스템으로의 비인가된 접근 또는 악성코드 감염과 같은 사이버보안 사고 발생 가능성을 높이는 요인이 되어 안전, 환경 및 상업적으로 중대한 피해를 야기할 수 있다. 따라서 증가하는 사이버위헙을 식별하고 대응하기 위하여 사이버 리스크 기반 접근법이 필요하게 되었다. 본 논문에서는 해사 사이버보안 동향을 분석하고 해상 사이버보안 시스템 구축을 위한 가이드라인을 제공하고자 한다.

• 대한건축학회논문집:구조계
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• 제35권8호
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• pp.131-138
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• 2019

Since concrete has a low tensile strength compared to the compressive strength, reinforced concrete flexural members represent easy crack occurance under a small load. In order to overcome this problem, steel fiber reinforced concrete has been developed to compensate the tensile strength and brittleness of members. However, in the design formula of the domestic building code, it is not specified in the design formula reflecting the material characteristics. Therefore, the field application of the steel fiber reinforced concrete have had many restrictions. In this study, a flexural tensile strength model of steel fiber reinforced concrete is proposed by collecting and analyzing the material properties of material test results conducted by various researchers, and verified by the test results of cracking and stiffness evaluation of flexural members based on the proposed model. As a result of this study, the flexural tensile strength model of steel fiber reinforced concrete which can reflect the mixing ratio and aspect ratio of the steel fiber was proposed and the validity of the proposed material model equation was evaluated from the load-deflection relationship in the flexural test of the slab member.

• 한국정보통신학회논문지
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• 제7권1호
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• pp.69-74
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• 2003

본 논문에서는 OFDM 신호방식을 사용하는 무선채널 환경에서 무선 멀티미디어에 적합한 클럭 동기복원 알고리즘을 제안한다. 제안된 클럭 동기복원 알고리즘의 기본적인 접근은 수신기의 채널 추정기로부터 추정된 채널의 주파수 응답을 획득하여 IFFT를 통해 채널의 충격 응답 또는 다중 경로 강도 프로 파일을 구하고 시간 영역에서 채널의 에너지가 집중된 일정 범위의 위치를 추적하는 것이다. 또한, 샘플링 클럭 오프셋이 ${\pm}$1∼3 샘플 있는 경우 64-QAM, 16-QAM의 성좌점을 분석하고, BER 성능을 확인한 결과 최적 샘플 지점에서의 성좌점과 BER 성능에 비하여 2 샘플 이상의 오프셋이 발생했을 경우에는 심한 성능 열화가 나타나는 것을 확인하였고, 시뮬레이션 결과로부터, 제안된 알고리즘이 주파수 선택적 페이딩 채널 하에서도 우수한 동기특성을 제공함을 알 수 있다.

• 한국토양비료학회지
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• 제14권2호
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• pp.76-82
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• 1981

수도체의 영업조건(營業條件) 특히 생육시기별(生育時期別) 규산(珪酸)의 공급조건(供給條件)과 도열병 발병(發病)과의 실계를 밝히고자 밀양(密陽)23호와 낙동(洛東)벼 (밀양(密陽)15호)를 공시(供試)하여 질소수준(窒素水準)을 달리하고 생육시기별(生育時期別) 규산(珪酸)의 공급조건(供給條件)을 달리하여 수경시험(水耕試驗)을 실시(實施)한 결과(結果)를 요약(要約)하연 다음과 같다. 1. 규산(珪酸) 시용(施用)으로 도열병 이병률(罹病率)은 현저(顯著)히 감소(減少)하였으며 이는 주(主)로 수도분중 규산함량(珪酸含量)의 증가와 질소(窒素) 함량(含量)의 감소(減少)에 기인(起因)되었다. 2. 유수형성기(幼穗形成期) 이후(以後)의 규산(珪酸) 시용(施用)으로 목도열병 이병수률(罹病穗率)은 현저(顯著)히 감소(減少)하여 규산(珪酸) 추비효과(追肥效果)의 가능성(可能性)을 보였다. 3. 규산(珪酸)의 도열병 억제효과(抑制效果)는 잎도열병보다 목도열병에서 뚜렷했다.

• 한국가축번식학회지
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• 제21권4호
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• pp.411-421
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• 1997

A survey was carried out to investigate the symptoms and occurance of reproductive disorder in Hanwoo(Korean native cattle). Data of the reproductive disorder of 561 heads from 28 farm households have been collected from Dec. '95 to Nov. '96 and analyzed calving no, nutritional body condition and housing forms. The results obtained are summarized as follows: 1. The incidence of reproductive disorder was 20.1% and the major common symptoms were repeat breeding(39.8%), anestrous(31.0%), nymphomania(10.6%) and subestrous(8.9%). 2. The incidence of reproductive disorder according to the calving no., that of heifer, calved one to two calving no. and over three calving no. were 20.6%, 13.9% and 34.5%, respectively. 3. Reproductive disorder incidence according to the nutritional body condition was 18.3%, 14.6% and 48.7% at body condition score(BCS) less than 2.0, 2.5 to 3.0 and over than 3.5, respectively. At BCS over 3.0, the symptoms of common reproductive disorder were repeat breeding(17.6%), anestrous(12.2%), nymphomania(10.8%) and subestrous(2.7%). 4. The incidence of reproductive disorder according to the housing form 15.8% and 34.6% for group feeding in open house and individual stanchion feeding in stall, respectively. In group feeding, reproductive disorder incidence of cows raised in space of more than 9.9$m^2$ per head was 14.1%, while that of cows raised less than 9.9$m^2$ per head was 18.2%. And incidence of repeat breeding, aneestrous and subestrous was more frequent in individual stanchion feeding than group feeding.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.127-134
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• 1993

The purpose of this study was to observe the control effect of hypersensitivity after periodontal treatment in the 19% microcrystalline hydroxyapatite containing toothpaste for the subject of 85 persons of both sexes, who complained hypersensitivity. At 2 weeks and 4 weeks after periodontal treatment, comparison of control effect was performed between the 19% microcrystalline hydroxyapatite containing toothpaste group and control group. The result were as follows, 1. The main causes of dentin hypersensitivity are the root exposure with gingival recession and cervical abrasion. 2. The occurance rate of hypersensitive tooth in the upper jaw was higher than that of the lower jaw, and more or less, the molar area showed more occlurance of hypersensitivity than the premolar and incisor area in both jaw. 3. Patients showed very sensitive response to the thermal stimulus, especially cold stimulus. 4. Exellent control effect of hypersensitivity in 19% microcrystalline hydroxyapatite containing toothpaste group showed 83.02% at 2weeks, 92.45% at 4weeks and these values were higher than the control group. In conclusion, we find that 19% microcrystalline hydroxyapatite containing toothpaste have the control effect of hypersensitivity and the proper toothbrushing method is the key in attaining more effectiveness of the toothpaste.

• Journal of Advanced Marine Engineering and Technology
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• 제15권4호
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• pp.29-45
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• 1991

Lip type stern tube sealing systems have used in almost all the middle or large ships which are being constructed in these days. It seems that the pressure fluctuation of the seal ring interspace, the cross-section profile and the materials quality of the seal rings have great effects on the sealing fuction of this sealing system. In this paper, the mechanical movement of lip seal ring which plays the most important role in stern tube sealing system and the possibility of leakage caused by pressure fluctuation are studied by theory and experiment. Using the finite element method for the axi-symetric object which receives the torsional load, the displacement and stress analysis of the seal rings, and also the possibility of crack occurance is checked by theoretical analysis. If the force which seal ring lip periphery receives is too small, there will be the possibility of leakage caused by the pressure fluctuation of the seal ring interspace, and if this force is too large, the frictional force between the seal ring and the liner will become problematical. The possibility of leakage caused by hardening of seal ring materials and creep phenomena of tested seal rings are also examined. The trial seal rings were designed and manufactured using the program of displacement and stress analysis developed in this study and the experimental apparatus to test the trial seal rings was also designed and manufactured. This trial seal rings were fitted in the experimental apparatus which was made in the same form as an actual stern tube. The one side of this apparatus was filled with sea water and the other side of it was filled with the lubricating oil. The leakage of oil and sea water was checked and the temperature was measured, rotating the propeller shaft at the constant velocity by D.C. motor. It was proved that the trial seal rings made in Viton rubber functioned excellenty but the trial seal rings made in N.B.R. rubber had problem in its durability.

• The Korean Journal of Pain
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• 제11권1호
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• pp.47-53
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• 1998

Background: Epidural coadministration of opioids and local anesthetics has provided excellent analgesia during postoperative period. However, it is usually associated with the occurance of many side effects which were induced by epidural morphine. Low dose of intravenous naloxone has been known to reduce morphine-induced side effects without reversing analgesia, but the effect of epidural naloxone has not been defined in human study. Therefore we evaluated side effects and analgesia when naloxone was administered via epidural route. Methods: Eighty patients having epiduro-general anesthesia for hysterectomy were randomly assigned to one of four study groups. As a mean of postoperative pain control, all received 2 mg of epidural morphine bolusly at 1 hr before the end of surgery and continuous epidural infusion was started by Two-day Infusor containing morphine 4 mg in 0.125% bupivacaine 100 ml with either none of naloxone(Group 1, n=20), 2 ug/kg/day of naloxone(Group 2, n=20), 3 ug/kg/day of naloxone(Group 3, n=20) or 4 ug/kg/day of naloxone(Group 4, n=20). Study endpoints included visual analog scales(VAS) for pain, severity of nausea, itching, somnolence and respiratory depression. They were assessed at 2, 4, 8, 16, 32, and 48 hr postoperatively. Results: VAS for pain showed significant difference in Group 4 compared with Group 1 at all of the evaluation time. Itching score decreased significantly in Group 3 and 4 after 8 hr postoperatively and nausea score decreased significantly in Group 3 after 4 hr postoperatively. Alertness score decreased significantly in Group 3 and 4 especially in early postoperative period. Conclusion: This study suggests that epidural naloxone reduce morphine-induced side effects in dose-dependent fashion without reversal of the analgesic effect of epidural morphine.

• 기본간호학회지
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• 제5권2호
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• pp.280-292
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• 1998

Pressure sores are a serious concerns in that respect to increasing risk of medical complications and medical costs. Prevention and care of pressure sores is an essential area of nursing practice. The nurse at ICU should be more careful of maintaining the skin integrity of patients especially than at any other place. This study was conducted to determine if the risk facotrs of pressure sores and nutritional status of the patients at risk for pressure sores is related the occurance of pressure sore. The risk group refers the patients having the below 14 scores of the braden scale. The 100 subjects were recruited from the ICU ward at an university hospital in Choongnam. The parameters for nutritional status are the blood chemistry including plasma protein, albumin, hemoglobin and the anthropometric measurements consisting of weight, BMI, LBM, the proportion of body fat, body fluid and triceps skin fold using bioimpedence analizer and caliper. The results are as follows : 1. The subjects were 55 years and stayed 8 days on average. Of the 100 subjects, males were 61%, neurologic/neurosurgical diseases were 68% and the incidence of pressure sores was 17% mainly occuring within 3days after the admission. 2. The present paralysis(or paraplegia) and edema(arm, leg, trunk) were showed more significantly the subjects with pressure sores than those without pressure sores. 3. Regarding with the nutritional status, the subjects with pressure sores had significantly lower the weight, BMI, LBM, body fluid, albumin than the ones without pressure sores. This results were supported the reports of previous studies that the decreased weight and albumin could be the important predictors of pressure sores. Thereafter we should encourage these factors to be utilized in predicting pressure sores for a comprehensive assessment. Nurse should identify patients at risk of the development of pressure sores, assess their nutritional status and dietary intake at regular intervals.

• Journal of Chest Surgery
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• 제26권2호
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• pp.75-79
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• 1993

Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.