• 대한전자공학회논문지
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• 제24권3호
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• pp.376-380
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• 1987

The closed-loop transfer function of 2-nd order PLL (phase-looked loop)of which loop filter has active-lag 1-st order is found. Considering the three criteria of system performance: the transient response time of the circuit, noise bandwidth by the linear analysis and stability which uses root-locus method, the optimum value of damping factor is 1.0 and the natural frequency which depends upon the signal frequency can be determined after consideration of the trade-off relationship between the transient response time and the noise bandwidth.

• Journal of Trauma and Injury
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• 제36권3호
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• pp.276-280
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• 2023

Fungal thrombophlebitis of the central vein is a rare, life-threatening disease associated with significant morbidity and mortality. It requires immediate central venous catheter removal and intravenous antifungal therapy, combined in some cases with either anticoagulation or aggressive surgical debridement. A 70-year-old male patient injured by a falling object weighing 1,000 kg was transferred to our hospital. A contained rupture of the abdominal aorta with retroperitoneal hematoma was treated with primary aortic repair, and a small bowel perforation with mesenteric laceration was treated with resection and anastomosis. After a computed tomography scan, the patient was diagnosed with thrombophlebitis of the left internal jugular vein and brachiocephalic vein. Despite antifungal treatment, fever and candidemia persisted. Therefore, emergency debridement and thrombectomy were performed. After the operation, the patient was treated with an oral antifungal agent and direct oral anticoagulants. During a 1-year follow-up, no signs of candidemia relapse were observed. There is no optimal timing of surgical treatment for relapsed fungal central thrombophlebitis. Surgical treatment should be considered for early recovery.

• The Journal of Korean Physical Therapy
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• 제14권1호
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• pp.27-37
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• 2002

This is the study of the knee joint injured patients at the orthopaedic surgery clinic where is located in Daejon, who has MCL combine injured ACL reconstruction caused by sport activity and accident during the period from Jan. 2001 to Oct. 2001. By comparing with groups between 7th case of I-group for MCL combined stitch and II-group for ACL reconstruction since 6weeks cast. We have been concluded with that following results. 1. Range of motion for the knee was not limited at 5th case(37%) of I-group, 6th case(42%) of II-group and the cases of Flexion deficit less then 10 -degree were 2nd case(13%) of I-group and II-group 1st case(8%) with no extension deficit more then 5 -degree. 2. The level of activity that tells you whether you are capable of exercise for six month after operation. It han been divided by 3 levels. The case of capable of doing low risk exercise(swimming, cycling, etc.) was 5th case of I-group, the case of capable of doing medium risk exercise(jogging, etc.) was 3rd case of I-group and 4th case of II-group and the case of capable of doing high risk exercise(football, etc.) were 3rd case of I-group and 3rd case of II-group. 3. The timing of the return to their job were average 6.4 weeks for I-group and average 22.9 weeks for II-group(P<.05, statistical difference). 4. There was no statistical difference between I-group and II-group for the timing of the return to their job(P>.05). 5. By using VAS to compare them there was no statistical difference between I-group and II-group of clinical results according to Lysholm scale.

• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.245-252
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• 2018

To improve survival rates of vitrified pig oocytes, the treatment of cytoskeletal stabilizer on an appropriate time is one of the possible approaches. However, the exact treatment timing and effect of cytoskeletal stabilizer such as cytochalasin B (CB) is not well known during oocyte vitrification procedures. Thus, the present study was conducted to determine optimal treatment timing of CB during vitrification and warming procedures. In experiment 1, the survival rates of the postwarming pig oocytes were analyzed by fluorescein diacetate (FDA) assays with 4 classifications. In results, post-warming oocytes showed significantly (p<0.05) decreased number of alive oocytes (31.8% vs. 86.4%) compared to fresh control. In detail, the significant difference (p<0.05) was found only in strong fluorescence (18.2% vs. 70.5%) not in intermediate fluorescence groups (13.6% vs. 15.9%). In experiment 2, CB was treated before (CB-Vitri) and after (Vitri-CB) vitrification. In results, group of Vitri-CB showed significantly (p<0.05) higher (91.6%) survival rates compared to group of CB-Vitri (83.7%), significantly (p<0.05) and comparable with group of Vitri Control (88.7%) by morphological inspection. In FDA assay results, group of Vitri-CB showed significantly (p<0.05) higher (44.2%) survival rates compared to groups of CB-Vitri (36.7%) and Vitri Control (35.1%). In conclusion, the increased survival rates of post-warming pig oocyte treated with Vitri-CB method are firstly described here. The main finding of present study is that the CB treatment during recovery could be helpful to refresh the post-warming pig oocyte resulting its improved survival rates.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.119-126
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• 2019

본 연구의 목적은 과제지향훈련이 알츠하이머 치매를 유발(${\beta}-amyloid$ 주입)시킨 흰쥐의 운동 및 인지기능 회복에 어떠한 영향을 미치는지를 알아보는 것이다. Sprague-Dawley계 흰쥐 30마리를 무작위 할당하여 치매 유발 이후 어떠한 처치도 실시하지 않은 대조군(n=15), 치매 유발 이후 과제지향훈련을 적용한 실험군(n=15)으로 나누었다. 훈련은 4주 동안 주 3회, 1일 1회, 20분간 시행하였다. 흰쥐들의 인지 및 운동기능 평가는 8자 미로 검사와 가로대 걷기 검사를 시행하였다. 8자 미로 검사는 시기별 군간 차이에서 14일과 28일에 유의한 차이를(p<.001) 보였다. 두 집단의 시기별 측정값의 차이가 유의하였다(p<.001). 또한 시기와 집단 간 상호작용도 유의한 차이가 있었다(p<.001). 사다리 걷기 검사는 시기별 군간 차이에서 14일과 28일에 유의한 차이를 보였다(p<.001). 두 집단의 시기별 측정값의 차이도 유의하였다(p<.001). 또한 시기와 집단 간 상호작용도 유의한 차이가 있었다(p<.001). 이상의 결과 알츠하이머 흰쥐에게 과제지향훈련은 운동 및 인지기능의 회복에 긍정적인 영향을 미치는 것으로 확인되었다. 더 나아가 과제지향훈련이 알츠하이머 치매환자의 운동 및 인지기능에 긍정적인 영향을 미칠 것으로 예상된다.

• 전력전자학회논문지
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• 제10권6호
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• pp.560-568
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• 2005

제안된 Multi-level PDP sustain Driver는 기존 L. Webber에 의해 제안된 방식에 비해 낮은 전압 rating을 갖는 소자를 사용하며 sustain 전압파형의 rising/falling 구간이 각각 2번의 공진에 의해 이루어진다. 본 논문에서는 rising time을 구성하는 3단계$(T_{r1},\;T_{i1},\;T_{r2})$의 변화에 따라 PDP의 방전 특성에 미치는 영향을 비교하고, 기존 LG전자의 상용화 제품인 42V6와 특성을 비교한다. 실험결과는 3단계의 rising time 중에 $T_{i1}$의 변화에 따른 특성 변화가 가장 크며, $T_{r2}$의 변화에 의한 영향도 있으며, $T_{r1}$의 변화에 따른 특성 변화는 거의 없다. 제안된 PDP driver는 $T_{r1}$이 60ns, $T_{i1}$이 120ns, $T_{r2}$가 350ns 인 경우, Full white display pattern에서 기존제품에 비해 휘도 $14.6\%$증가, 소비전력 $5.9\%$감소, panel 효율 $24.2\%$ 증가, module 효율 $21.2\%$증가 등 특성을 얻을 수 있었다. 실제 PDP module 응용에 적합할 것으로 기대된다.

• 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.

• 한국가스학회지
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• 제20권3호
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• pp.1-11
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• 2016

수압파쇄된 석탄층 메탄가스(coalbed methaen, CBM) 수평정의 생산거동을 예측하고 궁극가채매장량(estimated ultimate recovery, EUR)을 산출하기 위해 감퇴곡선분석, 유동영역분석, 유동물질평형분석을 활용하여 CBM 생산자료를 분석하였다. 가상의 생산자료를 발생시키기 위해 미국의 아팔라치안 분지(Appalachian basin)의 CBM 물성자료를 기반으로 저류층 모델을 구축하였다. 생산자료 분석 결과, 약 6~16년간 천이유동이 발생하였으며, 그 후에 경계지배 유동이 발생하였다. 천이유동 구간의 자료를 활용하여 생산자료 분석을 시행할 경우 예측된 생산자료와 가상의 생산자료 간의 큰 오차가 발생하였으며, 생산거동 예측이 불가함을 확인하였다. 경계지배유동의 생산자료 분석 결과, 1년 이상의 자료를 가지고 있을 때 EUR 오차율 5%이내에서 생산거동 예측이 가능한 것으로 확인되었다.

• 대한전자공학회논문지TC
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• 제37권10호
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• pp.26-36
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• 2000

이 논문에서는 고속전송 무선호출 시스템을 위한 스펙트럼 비중첩형 다중반송파 변복조 시스템을 설계하고 모의수행을 통하여 시스템의 성능을 평가한다. 기존의 무선호출 시스템은 주로 FSK 변조 방식이었으나 차세대방식에서는 계속 채용되기 어려우므로 대역효율이 높아 고속전송에 유리한 QAM 방식을 채택한다. 송신단은 iDEN/sup TM/의 4-16QAM 구조를 채택하였으며, 복조 알고리즘은 자동이득제어, 반송파동기 및 심벌동기를 고려한다. 한편, 동시전송 감쇠 채널을 극복할 수 있는 파일럿 심벌 보상 기술에 대해 분석하고 최적 파일럿 심벌 구조를 새롭게 제안하며 마지막으로 전체 4-16QAM 시스템의 성능평가 결과를 제시하였다.

• Journal of Biosystems Engineering
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• 제2권1호
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• pp.55-55
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• 1977

This experimental work was conducted in order to find out the optimum time of harvest of Japonica-type(Akibare) and Indica-type(Tong-il) rice variety for three harvesting systems by investigating the harvestirg losses and milling quality. The study was also concerned atout the nature and amount of grain losses incurred during the each sequence of post-harvest technologies, and based on these results, a modification of existing systems giving a minimum grain loss was attempted. Binder, combine, and traditional harvesting systems were tested in this study and five grain moisture levels were disposed according to the decrease of grain moisture. The results are summarized as follows: 1. The total losses of Akibare variety were ranged from 1.1 to 1.5 per cent for the traditional harvesting system, 2.1 to 4.8 percent for the harvesting system by use of binder, and 2.8 to 4.3 percent for the harvesting system by use of combine as the grain moisture content was reduced from 24 to 15 per cent. Milling recovery of the harvesting system by use of binder, 74.8~ 75.7 percent, was a little higher as it was compared to that of traditional harvesting system, 74. 3~75. 0 percent, and that of the harvesting system by use of combine, 73.8~ 75.0 per cent. Head rice recovery of mechanically dried paddy samples was higher than that of sun-dried paddy samples. 2. The total losses of Tong-il variety were ranged from 3.8 to 5.0 per cent for the traditional harvesting system, 5.2 to 10.0 percent for the system by use of binder, and 3.0 to 5.0 perent for the system by use of combine as the grain moisture was reduced from 28 to 16 percent.