• 제목/요약/키워드: Level set methods

검색결과 1,033건 처리시간 0.027초

α-cut Fuzzy TOPSIS 기법을 적용한 다기준 홍수취약성 평가 (MCDM Approach for Flood Vulnerability Assessment using TOPSIS Method with α Cut Level Sets)

  • 이규민;정은성;전경수
    • 한국수자원학회논문집
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    • 제46권10호
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    • pp.977-987
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    • 2013
  • 본 연구에서는 다기준 의사결정기법을 적용한 홍수취약성 평가에 내재되는 불확실성을 고려한 평가기법을 제시하였다. 홍수취약성평가과정은 3단계로 구성되며 1단계에서는 홍수와 연관되는 사회적, 경제적, 환경적 영향요인들 중에서 지역의 특성을 반영할 수 있는 평가인자를 선정하고 각 인자의 가중치를 책정한다. 이때 델파이 설문조사기법을 적용하여 의사결정자들의 의견을 수렴한다. 2단계는 평가자료를 수집하고 평가에 사용할 수 있도록 가공하는 단계이며 불확실성 문제를 해소하기 위하여 퍼지수를 적용하였다. 마지막단계에서 홍수취약성을 정량적으로 산정하여 취약지역의 우선순위를 도출한다. 본 연구에서는 퍼지수의 연산과정에서 발생하는 퍼지수의 과장 및 왜곡문제를 해소하기 위한 ${\alpha}$-cut fuzzy TOPSIS 방법을 적용하였다. 또한 수립한 평가기법으로 산정한 결과에 대하여 퍼지자료(fuzzy data)를 적용한 fuzzy TOPSIS, 크리스프(crisp) 자료를 사용한 TOPSIS, WSM등의 다양한 방법으로 평가한 결과들과의 상관관계분석을 수행하였다. 분석결과, ${\alpha}$-cut fuzzy TOPSIS 방법은 대체로 모든 방법과 높은 상관성을 나타내었다. 즉, 크리스프 자료와 퍼지자료를 사용하는 평가방법 사이에서 발생하는 결과의 차이가 ${\alpha}$-cut fuzzy TOPSIS를 이용하면 줄어드는 효과가 있다. 따라서본 연구에서 수립한 홍수취약성 평가방법은 불확실성 문제를 일정 부분 해소한 평가결과를 제시함으로서 치수정책 수립의 유용한 근거자료를 제공할 수 있다.

대한감각통합치료학회 역량기반 중재과정 교육커리큘럼 개발연구 (A Study on the Development of a Competency-Based Intervention Course Curriculum of the Korean Academy of Sensory Integration)

  • 남궁영;김경미;김미선;이지영
    • 대한감각통합치료학회지
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    • 제17권3호
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    • pp.26-45
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    • 2019
  • 목적 : 본 연구의 목적은 작업치료사가 감각통합 중재를 실행하는데 필요한 역량을 기반으로 중재 과정 교육 커리큘럼 개발하고, 중재과정 실시 및 교육만족도 확인을 통하여 대한감각통합치료학회의 역량기반 중재 교육과정을 제시하는데 있다. 연구방법 : 본 연구는 대한감각통합치료학회의 2019년 중재과정에 참여한 작업치료사 9명과 강사 3명을 대상으로 하였다. 중재과정의 교육목표 설정은 참여자 설문조사 방법을 통하여 교육요구 분석방법을 사용하였다. 중재과정의 역량기반 교육 프로그램 초안 및 교육 방법은 강사회의를 통하여 결정하였다. 중재교육과정은 실행계획에 따라 5일간 실시하였으며, 교육 만족도와 각 역량지표에 대한 중재과정 전후의 수행도 변화를 조사하였다. 결과 : 교육목표는 교육요구 분석 결과를 반영하여 '감각통합중재의 임상추론 과정을 학습 하고 적용한다'와 '감각통합중재 원칙을 적용하여 중재한다'로 하였다. 역량기반 중재과정 교육커리큘럼은 교육목표에 따라 Data driven decision making process 및 Ayres Sensory Integration에 관한 강의, 워크샵, 토의, 그리고 사례 중재 등으로 구성하여 총 42시간 교육을 실시하였다. 중재과정 참여자의 교육 만족도는 평균 4.48±0.73이었고, 수퍼바이저의 교육 만족도는 평균 3.92±0.71이었다. 두 집단 모두에서 Data driven decision making process 강의와 중재 목표 수립 강의의 만족도가 가장 높았고, 그룹 활동 및 토의에 대한 만족도가 가장 낮았다. 중재과정 전후, 역량모델의 전문가 역량군에 포함된 분석기술 역량의 두 가지 행동지표가 수행도에서 유의미한 변화를 보였다. 결론 : 본 연구는 교육 개발에 필요한 체계적 과정을 거쳐 교육요구 조사, 교육 커리큘럼 개발과 실시, 교육 만족도 조사를 실행하였다는 점에서 의의가 있다. 대한감각통합치료학회 내의 다른 교육커리큘럼 개발 시 기초자료로 사용될 수 있을 것으로 생각된다.

채혈 시간에 따른 부신피질 자극 호르몬 검사의 참고치 설정에 관한 고찰 (Consideration for Setting Reference Range for Adrenocorticotropic Hormone Test according to Blood Collection Time)

  • 박지혜;최진주;임수연;유선희;이선호
    • 핵의학기술
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    • 제27권1호
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    • pp.42-46
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    • 2023
  • Purpose The reference range described in Adrenocorticotropic Hormone reagent used in our laboratory is 10-60 pg/mL at 8 a.m. to 10 a.m., and 6-30 pg/mL at 8 p.m. to 10 p.m. However, in the case of outpatients, blood is mainly collected between 10 a.m. and 6 p.m., accounting for 57.8% of the total. Therefore, This study is intended to help make a more accurate diagnosis by reevaluating the reference range provided by the manufacturer of the Adrenocorticotropic Hormone reagent and setting split-timed reference range. Materials and Methods The patients collected blood before 10 a.m. were group A (68 people), and the patients collected blood after 10 a.m. were set to group B (80 people). A T-test was performed between groups to test their significance. And it was confirmed whether it was necessary to set the gender classification as a subgroup. The method of setting the reference range was calculated by the Bayesian's method and the Hoffmann's method. Results The reference range of Group A was 8.6 to 60.6 pg/mL by the Bayesian's method, and the Hoffmann's method was 3.6 to 61.3 pg/mL. The reference range of Group B was 6.9 to 50.5 pg/mL when applying the Bayesian's method, and the Hoffmann method's was 2.3 to 48.9 pg/mL. Conclusion This study was concluded that it was necessary to set the split-timed reference range. Through this study, the later the blood collection time, the lower the level of Adrenocorticotropic Hormone, indicating that blood collection time is important for patients with clinical significance. If a large number of subjects are selected and supplemented in the future, it is believed that systematic and accurate reference range can be set.

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Total Bilirubin Level as a Predictor of Suboptimal Image Quality of the Hepatobiliary Phase of Gadoxetic Acid-Enhanced MRI in Patients with Extrahepatic Bile Duct Cancer

  • Jeong Ah Hwang;Ji Hye Min;Seong Hyun Kim;Seo-Youn Choi;Ji Eun Lee;Ji Yoon Moon
    • Korean Journal of Radiology
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    • 제23권4호
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    • pp.389-401
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    • 2022
  • Objective: This study aimed to determine a factor for predicting suboptimal image quality of the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI in patients with extrahepatic bile duct (EHD) cancer before MRI examination. Materials and Methods: We retrospectively evaluated 259 patients (mean age ± standard deviation: 68.0 ± 8.3 years; 162 male and 97 female) with EHD cancer who underwent gadoxetic acid-enhanced MRI between 2011 and 2017. Patients were divided into a primary analysis set (n = 184) and a validation set (n = 75) based on the diagnosis date of January 2014. Two reviewers assigned the functional liver imaging score (FLIS) to reflect the HBP image quality. The FLIS consists of the sum of three HBP features, each scored on a 0-2 scale: liver parenchymal enhancement, biliary excretion, and signal intensity of the portal vein. Patients were classified into low-FLIS (0-3) or high-FLIS (4-6) groups. Multivariable analysis was performed to determine a predictor of low FLIS using serum biochemical and imaging parameters of cholestasis severity. The optimal cutoff value for predicting low FLIS was obtained using receiver operating characteristic analysis, and validation was performed. Results: Of the 259 patients, 140 (54.0%) and 119 (46.0%) were classified into the low-FLIS and high-FLIS groups, respectively. In the primary analysis set, total bilirubin was an independent factor associated with low FLIS (adjusted odds ratio per 1-mg/dL increase, 1.62; 95% confidence interval [CI], 1.32-1.98). The optimal cutoff value of total bilirubin for predicting low FLIS was 2.1 mg/dL with a sensitivity of 95.1% (95% CI: 88.9-98.4) and a specificity of 89.0% (95% CI: 80.2-94.9). In the validation set, the total bilirubin cutoff showed a sensitivity of 92.1% (95% CI: 78.6-98.3) and a specificity of 83.8% (95% CI: 68.0-93.8). Conclusion: Serum total bilirubin before acquisition of gadoxetic acid-enhanced MRI may help predict suboptimal HBP image quality in patients with EHD cancer.

하악전돌증환자에서 악교정수술후 저작근의 부피 및 교합력의 변화 (EFFECT OF MANDIBULAR SET BACK SURGERY ON VOLUMETRIC CHANGE AND BITE FORCE OF MASSETER MUSCLE)

  • 설정은;이명환;김창수;홍종락
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제34권3호
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    • pp.300-305
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    • 2008
  • Purpose: The purpose of our study was to evaluate the volume of pre- and post operative masseter muscle and bite force in mandibular prognathic patients treated with SSRO with the use of the 3D CT imaging technique and occlusal force meter. Materials and methods: The study group consisted of 12 patients with mandibular prognathism (5 males and 7 females) who underwent mandibular setback surgery (BSSRO) in the Department of Oral and Maxillofacial Surgery, Samsung medical center. Bite force was measured at pre op, post op 3, 6 and 12 months by occlusal force meter(GM10, Nagano Keiki, Japan) The preoperative CT examination of subjects was performed between one month prior to operation and one year after to operation. And muscle volume was measured. Result: As compared to preoperative measurements at 1 year postoperatively the masseter & internal pterygoid muscle volume were diminished (p<0.05) The bite force steadily recovered, so at postoperatively 6 months reached the preoperative level. And at 1 year after operation, the maximum bite force was significantly greater than preoperative levels. No significant correlation was presented between masseter muscle and bite force (p>0.05), internal pterygoid muscle and bite force (p>0.05). Conclusion: In this study, the results showed that volume and bite force of the masticatory muscles decreased significantly immediate after orthognathic surgery for mandibular set-back. However, reduction of maximum bite force disappears within 6 months after surgery.

TIME-DEPENDENT DEFORMATION OF POLYMER-BASED PROVISIONAL CROWN AND FIXED PARTIAL DENTURE MATERIALS

  • Pae Ahran;Jeong Mi-Sook;Kim Sung-Hun
    • 대한치과보철학회지
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    • 제43권6호
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    • pp.717-726
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    • 2005
  • Statement of problem. One of the common problems of provisional crown and fixed partial denture materials is that when they are subjected to constant loads for a long period of time, they exhibit a dimensional change (creep). Purpose. The aim of this study was to investigate the viscoelastic behaviour of polymer-based provisional crown and fixed partial denture materials with time at constant compressive load. Material and methods. Three dimethacrylate-based materials (Protemp 3 Garant, Temphase, Luxatemp) and one monomethacrylate-based material (Trim) were selected. Dimensional changes of the specimens were recorded by a LVDT to evaluate their viscoelastic behavior and creep strain. For all specimens, two loading procedures were used. At first, static compressive stress of 4 MPa was applied for 30 minutes and followed by 1 hour of strain recovery. Then, after 24 hours of water storage, the specimens were loaded again. The creep values between materials were statistically analyzed using one-way ANOVA and multiple comparison $Scheff\acute{e}$ test. Independent samples t-test was also used to identify the difference of creep strain between first and secondary loading conditions at the significance level of 0.05. Results. Following application of the first loading, Trim showed the highest maximum creep strain (32.7%) followed by Luxatemp, Protemp 3 Garant and Temphase, with values of 3.78%, 2.86% and 1.77%, respectively. Trim was significantly different from other materials (P<0.05), while there were no significant differences among Luxatemp, Protemp 3 Garant and Temphase (P>0.05). The highest recovery and permanent set of Trim, were significantly different from those of others (P<0.05). At the secondary loading of the dimethacrylate-based materials, creep deformation, recovery and permanent set decreased and the percentage of recovery increased, while in Trim, all values of the measurements increased. This result showed that the secondary loading at 24 hours produced a significant creep magnitude. Conclusion. The dimethacrylate-based provisional crown and fixed partial denture materials showed significantly higher creep resistance and lower deformation than the monomethacrylate-based material. Thus, monomethacrylate-based materials should not be used in long-term stress-bearing situations.

자동차를 통한 대기오염물질의 배출에 따른 민법상 불법행위책임의 성립 여부: 대법원 2014. 9. 4. 선고 2011다7437 판결을 중심으로 (Review of a Tort Case regarding Liability for the Production of Air Pollutant-emitting Vehicles: Supreme Court Decision 2011Da7437, Decided on September 4, 2014)

  • 이선구
    • 한국환경보건학회지
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    • 제42권6호
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    • pp.375-384
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    • 2016
  • Objectives: This paper analyzes the intersection of tort law and environmental health in a recent court decision. Methods: This paper analyzes Supreme Court Decision 2011Da7437, Decided on September 4, 2014 and related lower court decisions. Results: The plaintiffs sought financial compensation from the defendants, arguing that air pollutants in gases emitted by vehicles produced by the defendants had caused them to acquire respiratory diseases. The district court highlighted the need to mitigate the burden of proof for the plaintiffs, but proceeded to review whether the plaintiffs proved the actual toxicity levels of the air pollutants, whether the defendant's vehicles were the main source of the emissions, the plaintiff's level of exposure to the pollutants, and causation between the emissions and the injury. By doing so, the district court required the plaintiffs to prove both indirect and direct facts of causation, increasing burden of proof for plaintiffs. The appellate court upheld the district court's decision, adding that the defendant's conduct did not constitute an illegal act because it did not violate the emissions standards set by environmental law. The Supreme Court upheld the appellate court's decision, reasoning that the epidemiological evidence cannot establish a direct causation for diseases that lack specificity. Conclusion: This case demonstrates that discussions in environmental health have significance in tort lawsuits. For each fact that the plaintiffs and defendants attempted to prove, environmental health research studies were offered as evidence. In addition, the courts decided the legality of the defendant's conduct based on emission standards set by environmental law.

Polish of interface areas between zirconia, silicate-ceramic, and composite with diamond-containing systems

  • Pott, Philipp-Cornelius;Hoffmann, Johannes Philipp;Stiesch, Meike;Eisenburger, Michael
    • The Journal of Advanced Prosthodontics
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    • 제10권4호
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    • pp.315-320
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    • 2018
  • PURPOSE. Fractures, occlusal adjustments, or marginal corrections after removing excess composite cements result in rough surfaces of all-ceramic FPDs. These have to be polished to prevent damage of the surrounding tissues. The aim of this study was to evaluate the roughness of zirconia, silicate-ceramic, and composite after polish with different systems for intraoral use. MATERIALS AND METHODS. Each set of 50 plates was made of zirconia, silicate-ceramic, and composite. All plates were ground automatically and were divided into 15 groups according to the treatment. Groups Zgrit, Sgrit, and Cgrit received no further treatment. Groups Zlab and Slab received glaze-baking, and group Clab was polished with a polishing device. In the experimental groups Zv, Sv, Cv, Zk, Sk, Ck, Zb, Sb, and Cb, the specimens were polished with ceramic-polishing systems "v", "k", and "b" for intraoral use. Roughness was measured using profilometry. Statistical analysis was performed with ANOVA and $Scheff{\acute{e}}$-procedure with the level of significance set at P=.05. RESULTS. All systems reduced the roughness of zirconia, but the differences from the controls Zgrit and Zlab were not statistically significant (P>.907). Roughness of silicate ceramic was reduced only in group Sv, but it did not differ significantly from both controls (P>.580). Groups Cv, Ck, and Cb had a significantly rougher surface than that of group Clab (P<.003). CONCLUSION. Ceramic materials can be polished with the tested systems. Polishing of interface areas between ceramic and composite material should be performed with polishing systems for zirconia first, followed by systems for veneering materials and for composite materials.

탄성밴드 사용유무에 따른 발레 아라베스크 동작의 운동 역학적 분석 (The Biomechanical Analysis of Ballet Arabesque by Using Elastic Band)

  • 김민정;이경옥
    • 한국운동역학회지
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    • 제25권3호
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    • pp.265-274
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    • 2015
  • Objective : The purpose of this study was to analyze the effect of the elastic band on ballet arabesque based on kinematics analysis. Methods : To observe the effect of the elastic band, the availability of the elastic band during movement was set as the independent variable, and the dependent variables were set by using factors from two different categories such as motor mechanics and kinematics variables. For motor mechanics variable, the muscle activity and the center of pressure(COP)'s trajectory and velocity were used. Furthermore, the physical angle was used for kinematic variables. Data samples from the experiment was used to understand the correlation between independent and dependent variables while using paired samples t-test as a data analysis tool. Results : After analyzing the result of experiment, the usage of the Elastic band on ballet arabesque movement seemed to increase the activity of the agonistic muscle, which is mainly used for movement, and to improve the stability of the supporting leg by decreasing the trajectory and velocity of the center of pressure(COP). Moreover, the elastic band increased the level of elevation of the stretching leg with reducing the angle of the hip joint that resulted into a more stable movement and furthermore providing more beauty while standing on it. Conclusion : The movement training program while the using elastic band are expected to lead to appropriate muscular development and reduce the muscle imbalance, which usually occurs to dancers, during training with unfamiliar specific movements or strengthening muscular strength for a specific movement. In addition, this work is expected to be used as a training reference to understand and learn the fundamentals of movements of ballet and other dance fields.

고속네트워크에서 네트워크 혼잡상태에 적응적인 UDT 병렬전송 기법 (UDT Parallel Transfer Technologies Adaptive to Network Status In High Speed Network)

  • 박종선;조기환
    • 스마트미디어저널
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    • 제2권4호
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    • pp.51-59
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    • 2013
  • 백본망의 지속적인 고속화는 충분한 가용대역폭을 제공하고 있지만 장거리 대용량 데이터 전송에서 이를 잘 활용하지 못하고 있다. 이는 대부분 응용들이 TCP를 사용하는데서 원인을 찾을 수 있으며 TCP는 전송메커니즘 특성상 고속네트워크에서 신속한 가용대역폭 확보가 어렵다. UDT는 응용계층 전송프로토콜로써 고속네트워크에서 용을 목표 설계된 잘 알려진 프로토콜이다. 본 논문에서는 네트워크 혼잡상태에 적응적인 UDT 병렬전송기법에 대해 제안하고 다음 두 가지 관점에서 성능을 평가한다. 첫째, UDT Rate 혼잡제어에 따른 전송성능을 측정하고 UDT의 성능과 비교한다. 둘째, 네트워크 상태에 적응적인 UDT 병렬전송기법의 전송성능에 대해 분석한다. 실험결과 UDT Rate 혼잡제어의 경우 jitter를 30ms로 설정한 경우 RTT 100ms 구간에서 UDT에 비해 106%의 성능향상을 보였다. 또한 Rate 혼잡제어를 적용한 병렬전송의 경우 jitter를 20ms로 설정한 경우 RTT 400ms 구간에서 UDT 병렬전송에 비해 107% 성능향상을 실험을 통해 확인하였다.

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