• 제목/요약/키워드: effective clearance

검색결과 208건 처리시간 0.038초

DLC 코팅된 SACM645 소재의 마모 특성 (Wear Property of SACM645 Material with DLC Coating)

  • 김남석;남기우;박종남;안석환;김현수
    • 한국해양공학회지
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    • 제24권6호
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    • pp.76-80
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    • 2010
  • Oil hydraulic piston pumps are being extensively used around the world, because of their simple design, light weight, effective cost, etc. An oil hydraulic pump is likely to have the serious problems of high leakage, friction, and low energy efficiency after a long period of use. In an oil hydraulic piston pump, the clearance between the valve block and piston plays an important role for volumetric and overall efficiency. In this study, the wear property of the SACM645 material with DLC coating used for a hydraulic piston pump was determined by experimentation with variable heat treatment. To investigate the effect according to the piston surface condition, five different types of specimens were prepared. The maximum tensile strengths of the QT and QT Nitration specimens had similar values of about 800 MPa, but the strains indicated a big difference. In a wear test, the wear characteristic of the DLC coating specimen was shown to be excellent. The QT, QT + IH, QT + Nitration, and matirx specimen showed similar wear characteristics. In the case of a dry condition without oil, the DLC coating specimen had good wear resistance, with no wear shown.

Digital Human Simulation을 활용한 방사성 폐기물 처리장 주제어실의 인체공학적 평가 (Ergonomic Evaluation of a Control Room Design of Radioactive Waste Facility using Digital Human Simulation)

  • 이백희;장윤;정기효;정일호;유희천
    • 대한인간공학회지
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    • 제29권3호
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    • pp.383-391
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    • 2010
  • The present study evaluated a preliminary control room (CR) design of radioactive waste facility using the $JACK^{(R)}$ human simulation system. Four digital humanoids ($5^{th}$, $50^{th}$, $95^{th}$, and $99^{th}$ percentiles) were used in the ergonomic evaluation. The first three were selected to represent 90% of the target population (Korean males aged 20 to 50 years) and the last to reflect the secular trend of stature for next 20 years in South Korea. The preliminary CR design was assessed by checking its compliance to ergonomic guidelines specified in NUREG-0700 and conducting an in-depth ergonomic analysis with a digital prototype of the CR design and the digital humanoids in terms of postural comfort, reachability, visibility, and clearance. For identified design problems, proper design changes and their validities were examined using JACK. A revised CR design suggested in the present study would contribute to effective and safe operations of the CR as well as operators' health in the workplace.

Experience and pharmacokinetics of Levetiracetam in Korean neonates with neonatal seizures

  • Shin, Jae Won;Jung, Yun Seob;Park, Kyungsoo;Lee, Soon Min;Eun, Ho Seon;Park, Min Soo;Park, Kook In;Namgung, Ran
    • Clinical and Experimental Pediatrics
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    • 제60권2호
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    • pp.50-54
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    • 2017
  • Purpose: The aims of this study were to evaluate the safety and pharmacokinetics of levetiracetam (LEV) in neonates with seizures and to establish a population pharmacokinetics (PPK) model by using the software NONMEM. Methods: A retrospective analysis of 18 neonatal patients with seizures, who were treated with LEV, including 151 serum samples, was performed. The mean loading dose was 20 mg/kg, followed by a mean maintenance dose of 29 mg/kg/day. Results: Seventeen neonates (94%) had seizure cessation within 1 week and 16 (84%) remained seizure-free at 30 days under the LEV therapy. The mean serum concentration of LEV was $8.7{\mu}g/mL$. Eight samples (5%) were found above the therapeutic range. No serious adverse effects were detected. In the PPK analysis for Korean neonates, the half-life was 9.6 hours; clearance, 0.357 L/hr; and volume of distribution, 4.947 L, showing differences from those in adults. Conclusion: LEV is a safe and effective option for the treatment of neonatal seizures with careful therapeutic drug monitoring.

Ca 혼합처방인 SG 및 GN이 난소절제 백서의 골다공증에 미치는 영향 연구 (Effects of Herbal Compounds with Tuna bone Powder on Rodent Osteoporosis Model Induced by Ovariectomy)

  • 지규용;윤군애;김영만
    • 동의생리병리학회지
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    • 제17권5호
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    • pp.1281-1287
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    • 2003
  • In this research 2 sample compounds are made and analyzed in terms of the in vivo and in vitro effects on the ovariectomized rats. The 2 compounds are prescribed based on pathologic patterns of osteoporosis, and added calcium citrate from tuna bone powder. SG is for menopausal women(Type I osteoporosis) and GN is for senile men(Type II osteoporosis). Through these, SG manifested Significant effects on the T4, osteocalcin level, and through the histological changes of osteoid tissues and lipocytes. On the other hand GN showed significant increase on the biochemical markers of osteocalcin, TALP, even in histological features and bone mineral density and intensity of femur it showed meaningful changes. But In the results of RT-PCR on the IL-1β, IL-6, TNF α, there weren't coherent results with in vivo test, that is they were increased in the sample compound group than control group. These increase of bone resorption was seemed that those cytokines had the osteoclasts promote their own resorptive functions after fragments of bone tissues were increased in the cavity. And this clearance of inner fragments help the bone to strengthen its own substance. Putting together above facts, the sample compounds, SG and GN, made of tuna bone powder and herbal solutions are predicted that there would be pharmacological actions improving the osteoporosis initiated from the disorders of calcic absorption and increase of bone resorption. And GN has more effective actions than SG at least in the animal model.

부인과 암 이후 이차적인 다리 림프 부종 환자에게 적용한 림프흡수 마사지의 효과 (Effects of Manual Lymph Drainage on Patients with Secondary Lymphedema of Legs After Gynecologic Cancer)

  • 정성관;이승병
    • 대한정형도수물리치료학회지
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    • 제22권2호
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    • pp.35-39
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    • 2016
  • Background: The superficial lymphatic system is divided into areas called lymphatic territories which are separated by watersheds. When the lymphatic system fails to remove its load either due to surgery, radiotherapy or some congenital malformation of it then the fluid and the proteins and wastes contained within it accumulates in that territory. Anastomotic connections exist across the watersheds and while they can work unaided manual lymph drainage (MLD) can significantly help drainage across them into unaffected lymphatic territories. The purpose of the study is to examine the effectiveness of a manual technique in moving fluids and softening hardened tissues using a tape measure and Patient-Specific Functional Scale. Methods: We examined the movement of fluids from the affected limbs of lymphedema patients who underwent a standardized 30-min treatment using the Dr. Vodder method of MLD. We chose a typical cross section of patients with secondary leg or secondary arm lymphedema. The lymphedema patient was also measured after the conclusion of treatment and underwent a follow-up control measurement, within 8 weeks. Both evaluation tools indicated a movement of fluid to different and unblocked lymphatic territories as well as a softening of tissues in some of the affected limbs. Results: MLD is an effective means of fluid clearance when it accumulates as a consequence of a failure of the lymphatic system. It seems likely that MLD has a systemic effect on the lymphatic system and that it can improve flow from otherwise normal tissues. Conclusions: It is hypothesized that a series of treatments would result in even more significant improvements.

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우리나라 컨테이너 물류 정보 교환에 관한 연구 (A Study on the Information Exchange in Container Cargo Logistics)

  • 박남규
    • 한국항해학회지
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    • 제18권3호
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    • pp.81-103
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    • 1994
  • Increasing costs and competition in the global trade and transportation arena have led to a search for effient, cost-effective, particularly through the application of computer and information technologies. Most recently the introduction of Electronic Data Interchange(EDI) technologies in both trading and trade facili-tation activitiess have bagun to change the complextion of the international transport space. Korea as well as the other developing countries has become aware of the need to embrace EDI strate-gies in order to maintain a competitive market position with their more technologically advanced neighbou-ring and international trading partners. A way of EDI implementation, KMPA has invested large budgets in the research of the EDI since 1990. As the result of study in EDI of transport, KL-Net(Korea Logistics Network) was organized for the EDI business in cargo logistics. In spite of these KMPA's activities, the development plan of container logistics data interchange is not good and useful. So a new model of EDI in transportation is required by using the concepts of cargo data sharing. The purpose of this paper is to suggest a new way of container logistics data interchange model. This paper therefore analyze the information flow in the current container logistics and find the problem in the area to derive a new model. The followings are the results of this paper : (1) There are many problems and user's requirements in container logistics data interchange in Korea. (2) Many messages of UN/EDIFACT are able to be used in container logistics data interchange. (3) The container cargo data are stored in Container Logistics Network(CL-Net) database. And when necessary by requesting message transmission, the container logistics data interchange is possible. (4) Customs cargo clearance system and PORT-MIS can be linked to CL-Net. If the systems, however, are to introduce EDI in data interchange, the quality of user's software has to be assured.

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해양 정밀측위 활용을 위한 GPS 정밀위성궤도 보간 연구 (A Study of GPS Precise Ephemeris Interpolation for Maritime Precise Positioning Applications)

  • 조득재;박상현
    • 한국항해항만학회지
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    • 제33권10호
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    • pp.699-702
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    • 2009
  • 현재 선박들은 교량 및 시설물 통과시 선박의 흘수에 토대를 둔 대략적인 예측치로 안전통항 높이를 결정하고 있으나 표준선박을 제외한 바지선 등이 항해시 바다의 조석간만에 따라 안전통항 높이 예측치가 부정확할 때가 종종 있다. 또한 지구 온난화 및 국지적 해면 상승으로 인한 해양재난으로 인명피해와 재산피해가 점차 급증하고 있으며, 지진이 아닌 유사 재난해파에 대해서는 경고할 수 없는 문제가 상존하고 있다. 본 논문에서는 선박 등이 안전통항을 가능하게 하고, 쓰나미와 같은 재난해파로부터 피해를 절감시키기 위해 필요한 위성항법 기반의 정밀수직측위 기술들 중 해양 정밀측위 활용을 위한 GPS 정밀위성궤도의 보간에 관한 연구를 수행하였다. 본 논문에서 사용하는 GPS 정밀위성궤도는 국제 GNSS 서비스 기구인 IGS로부터 제공받을 수 있지만 데이터 간격이 15분으로 실시간 정밀측위시 최대 15분의 위성궤도 지연으로 오차가 발생한다. 따라서 본 논문에서는 실시간 정밀측위 오차를 줄이기 위해 보간시 발생하는 발진현상을 효과적으로 제거하는 방법을 제안하였으며, 마지막으로 보간된 GPS 위성궤도의 정확도를 분석하였다.

The Deep Inferior Epigastric Perforator and Pedicled Transverse Rectus Abdominis Myocutaneous Flap in Breast Reconstruction: A Comparative Study

  • Tan, Shane;Lim, Jane;Yek, Jacklyn;Ong, Wei Chen;Hing, Chor Hoong;Lim, Thiam Chye
    • Archives of Plastic Surgery
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    • 제40권3호
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    • pp.187-191
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    • 2013
  • Background Our objective was to compare the complication rates of two common breast reconstruction techniques performed at our hospital and the cost-effectiveness for each test group. Methods All patients who underwent deep inferior epigastric perforator (DIEP) flap and transverse rectus abdominis myocutaneous (TRAM) flap by the same surgeon were selected and matched according to age and mastectomy with or without axillary clearance. Patients from each resultant group were selected, with the patients matched chronologically. The remainder were matched for by co-morbidities. Sixteen patients who underwent immediate breast reconstruction with pedicled TRAM flaps and 16 patients with DIEP flaps from 1999 to 2006 were accrued. The average total hospitalisation cost, length of hospitalisation, and complications in the 2 year duration after surgery for each group were compared. Results Complications arising from both the pedicled TRAM flaps and DIEP flaps included fat necrosis (TRAM, 3/16; DIEP, 4/16) and other minor complications (TRAM, 3/16; DIEP, 1/16). The mean hospital stay was 7.13 days (range, 4 to 12 days) for the pedicled TRAM group and 7.56 (range, 5 to 10 days) for the DIEP group. Neither the difference in complication rates nor in hospital stay duration were statistically significant. The total hospitalisation cost for the DIEP group was significantly higher than that of the pedicled TRAM group (P<0.001). Conclusions Based on our study, the pedicled TRAM flap remains a cost-effective technique in breast reconstruction when compared to the newer, more expensive and tedious DIEP flap.

Variables Influencing the Depth of Conscious Sedation in Plastic Surgery: A Prospective Study

  • Yeo, Hyeonjung;Kim, Wonwoo;Park, Hyochun;Kim, Hoonnam
    • Archives of Plastic Surgery
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    • 제44권1호
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    • pp.5-11
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    • 2017
  • Background Conscious sedation has been widely utilized in plastic surgery. However, inadequate research has been published evaluating adequate drug dosage and depth of sedation. In clinical practice, sedation is often inadequate or accompanied by complications when sedatives are administered according to body weight alone. The purpose of this study was to identify variables influencing the depth of sedation during conscious sedation for plastic surgery. Methods This prospective study evaluated 97 patients who underwent plastic surgical procedures under conscious sedation. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and glucose levels were measured. Midazolam and ketamine were administered intravenously according to a preset protocol. Bispectral index (BIS) recordings were obtained to evaluate the depth of sedation 4, 10, 15, and 20 minutes after midazolam administration. Associations between variables and the BIS were assessed using multiple regression analysis. Results Alcohol intake and female sex were positively associated with the mean BIS (P<0.01). Age was negatively associated with the mean BIS (P<0.01). Body mass index (P=0.263), creatinine clearance (P=0.832), smoking history (P=0.398), glucose (P=0.718), AST (P=0.729), and ALT (P=0.423) were not associated with the BIS. Conclusions Older patients tended to have a greater depth of sedation, whereas females and patients with greater alcohol intake had a shallower depth of sedation. Thus, precise dose adjustments of sedatives, accounting for not only weight but also age, sex, and alcohol consumption, are required to achieve safe, effective, and predictable conscious sedation.

12주간의 수중 운동을 수행 한 여성노인의 장애물 보행 특성 (The Characteristics of Obstacle Gaits in Female Elders after 12 Weeks of an Aquatic Exercise Program)

  • 김석범;유연주
    • 한국운동역학회지
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    • 제19권3호
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    • pp.539-547
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    • 2009
  • 본 연구의 목적은 낙상 예방을 위한 12주간의 수중 운동 수행 후 장애물 보행의 특성을 운동학 및 운동역학적으로 분석하는 것이다. 여성 노인 8명이 참여하였으며, 대상자들은 수중 운동 전 후에 네 높이의 장애물(0, 2.5, 5.1, & 15.2cm)을 자기선호 속도로 넘었다. 수중 운동 수행 후 고관절의 최대각, 최소각, ROM(Range Of Motion)이 유의하게 증가하였으며, Swing 과 Stance 국면에서 소요시간은 줄어들었다. 수중 운동 후 모든 높이에서 보폭은 유의하게 증가하였고, 보간은 줄어들었다. 수중 운동 후 장애물을 넘는 순간 장애물과 오른발 사이의 수직 최단거리는 증가하였고(15.2cm 장애물 제외), 장애물을 넘는 속도는 증가하였다. 수중 운동 수행 후 제동력, 추진력, 제동 운동량, 추진 운동량은 통계적으로 유의하게 변화하였다. 12주간의 수중 운동은 여성 노인의 근력과 평형성을 향상시켰으며 이는 낙상과 관련된 장애물 보행의 운동학 및 운동역학적 변인의 변화를 가져와 여성 노인들이 장애물을 안전하고 신속하게 넘을 수 있었다. 따라서 노인에게 보행 능력 향상과 낙상 예방 운동으로 수중 운동이 추천된다.