• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.439-442
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• 1997

For the treatment of arteriovenous malformations (AVM), we developed a new liquid embolic material and named it Embol. The material was pre-tested in an in vitro AVM model and tested in rete mirabile of pigs that is similar in structure with the AVM in human. We report on the construction of the in vitro AVM model, the pre-test results of Embol in the AVM model, and the animal test result in pig rete mirabile.

• 대한치과교정학회지
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• 제5권1호
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• pp.51-56
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• 1975

In orthodontic field, the study on gnathostatic model is very important to the diagnosis and analysis of malocclusion. The purpose of this study is to observe that relation of orbital plane and upper canine in Koreans. We selected 230 cases with normal occlusion, 124 male and 106 female cases aged from 12 years to 25 years, to prepare 230 gnathostatic models, and measured the distance from midpoint of mesio-distal distance of upper canine to orbital plane in gnathostatic model. The results obtained were as follows: 1) The mean value of the distance from upper canine to orbital plane showed no significant change with age. 2) The mean value of the distance from the upper canine to orbital plane was -3.11mm in male and -3.84mm in female. 3) The orbital plane passed through the upper canine in normal occlusion of Koreans.

• Journal of International Society for Simulation Surgery
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• 제2권2호
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• pp.76-79
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• 2015

One of the most serious complications after head and neck radiation is osteoradionecrosis (ORN) of the jaw. The etiology of ORN is extraction, minor dental procedure or dental implant surgery. When ORN of the jaw progressed to stage III, free fibular flap is the most useful methods for reconstruction. In this case report, a 67-year-old ORN patient who underwent fibular free flap reconstruction using simulation surgery with 3-dimensional rapid prototype (3D RP) model was reviewed. After partial mandibulectomy, a osteocutaneous fibula flap was used for reconstruction. Oro-cutaneous fistula was resolved after operation. Patients reported improved food intake after operation without pus discharge. Functional and esthetic results showed successful reconstruction.

• Journal of Information Processing Systems
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• 제17권3호
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• pp.441-452
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• 2021

Federated learning provides an efficient integrated model for distributed data, allowing the local training of different data. Meanwhile, the goal of multi-task learning is to simultaneously establish models for multiple related tasks, and to obtain the underlying main structure. However, traditional federated multi-task learning models not only have strict requirements for the data distribution, but also demand large amounts of calculation and have slow convergence, which hindered their promotion in many fields. In our work, we apply the rank constraint on weight vectors of the multi-task learning model to adaptively adjust the task's similarity learning, according to the distribution of federal node data. The proposed model has a general framework for solving optimal solutions, which can be used to deal with various data types. Experiments show that our model has achieved the best results in different dataset. Notably, our model can still obtain stable results in datasets with large distribution differences. In addition, compared with traditional federated multi-task learning models, our algorithm is able to converge on a local optimal solution within limited training iterations.

• 대한간호학회지
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• 제28권2호
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• pp.270-279
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• 1998

Since death is an extremely subjective and unique experience, if we take into account the lack of understanding about death due to the difficulty in methodology, it is very important to try to understand the subjectivity of death. In this respect, Q-methodology that explains and shows the respondent's subjectivity by objectifying his subjectivity is employed as a solution to the questions in this study. Therefore, the purpose of this study was to provide data on how medical personnel should treat their patients, when it comes to death : by finding out the opinions of those who are being treated, namely the patients, and those who are providing the treatment, namely the medical personnel. It also by examined the characteristics and relationships between these two groups on attitudes to death. The results of this study show that medical per sonnel have two(fate-receipient, reality-oriented) types of response and patients have three (religion-dependent, science-adherent, sardonist) types. Medical personnel saw patients as having three (life-attached. traditionalist, death-rejector) types of response and to patients saw medical personnel as having two (rationalist, humanist)types. The relationship between the above-mentioned types will be examined in a coorientation model, the subjectivity of the medical personnel and the patient toward death indicates a relatively high understanding between the two groups under the great proposition of 'death'. Therefore, in their relationship with people who are facing death, the provider of care, namely the medical personnel, should identify the subjectivity of the patient before approaching them. By doing this, they can minimize the conflicts they might experience in establishing a therapeutic relationship, reduce suffering, and help the patient in greeting a more comfortable death. Throughout the study, Q-methodology expands our understanding of coorientation model that has only been approached with R-methodology. This study confirmed Q's potentiality and its validity in human subjective matters.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.7359-7363
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• 2015

Background: As a result of significant progress made in treatment of many types of cancers during the last few decades, there have been an increased number of patients who do not experience mortality. We refer to these observations as cure or immune and models for survival data which include cure fraction are known as cure rate models or long-term survival models. Materials and Methods: In this study we used the data collected from 438 female patients with breast cancer registered in the Cancer Research Center in Shahid Beheshti University of Medical Sciences, Tehran, Iran. The patients had been diagnosed from 1992 to 2012 and were followed up until October 2014. We had to exclude some because of incomplete information. Phone calls were made to confirm whether the patients were still alive or not. Deaths due to breast cancer were regarded as failure. To identify clinical, pathological, and biological characteristics of patients that might have had an effect on survival of the patients we used a non-mixture cure rate model; in addition, a Weibull distribution was proposed for the survival time. Analyses were performed using STATA version 14. The significance level was set at $P{\leq}0.05$. Results: A total of 75 patients (17.1%) died due to breast cancer during the study, up to the last follow-up. Numbers of metastatic lymph nodes and histologic grade were significant factors. The cure fraction was estimated to be 58%. Conclusions: When a cure fraction is not available, the analysis will be changed to standard approaches of survival analysis; however when the data indicate that the cure fraction is available, we suggest analysis of survival data via cure models.

• 보건행정학회지
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• 제9권1호
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• pp.156-177
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• 1999

The current method of rate adjustment for inflation is based on the evaluation of the financial performance of hospitals. The method has the disadvantage such as too complicated, expensive process as well as low reliability. This study, therefore, develops the 'Korean Medical Insurance Economic Index(MIEI)' as a new model for the rate adjustment with the use of the macro economic indices. In addition, we calculate the 1992∼1998 rate adjustment with the MIEI, and examines the validity of the MIEI by comparing with the conventional method. Medical costs are classified into nine categories : physician salaries, nurse·pharmacist·medical technician salaries, assistants & others salaries, material cost(by imports), material cost(by domestics), depreciation & rent paid(by imports), depreciation & rent paid(by domestics), power utilities, other administrative costs. Then the category weight which is the ratio of category in the total cost is calculated. Macro economic indices are selected for each cost category in order to reflect the concept of the each cost category and inflation during the year of 1992∼1998. Finally MIEI which integrate all category according to the category weight and selected macro indices is calculated. The mean of hospital MIEI which weighting by amount paid by insurers was cacluated. The result from the application of empirical data to the MIEI model is very similar to that of the current method. Furthermore, this method is very simple and also easy to get social consensus. This MIEI model can be replaced the current method based on the analysis of the financial performance for the adjustment of medical fees.

• 한국의학물리학회지:의학물리
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• 제30권4호
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• pp.94-103
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• 2019

Purpose: To evaluate the clinical feasibility of knowledge-based planning (KBP) for volumetric-modulated arc radiotherapy (VMAT) in spine stereotactic body radiotherapy (SBRT). Methods: Forty-eight VMAT plans for spine SBRT was studied. Two planning target volumes (PTVs) were defined for simultaneous integrated boost: PTV for boost (PTV-B: 27 Gy/3fractions) and PTV elective (PTV-E: 24 Gy/3fractions). The expert VMAT plans were manually generated by experienced planners. Twenty-six plans were used to train the KBP model using Varian RapidPlan. With the trained KBP model each KBP plan was automatically generated by an individual with little experience and compared with the expert plan (closed-loop validation). Twenty-two plans that had not been used for KBP model training were also compared with the KBP results (open-loop validation). Results: Although the minimal dose of PTV-B and PTV-E was lower and the maximal dose was higher than those of the expert plan, the difference was no larger than 0.7 Gy. In the closed-loop validation, D_1.2cc, D_0.35cc, and D_mean of the spinal cord was decreased by 0.9 Gy, 0.6 Gy, and 0.9 Gy, respectively, in the KBP plans (P<0.05). In the open-loop validation, only D_mean of the spinal cord was significantly decreased, by 0.5 Gy (P<0.05). Conclusions: The dose coverage and uniformity for PTV was slightly worse in the KBP for spine SBRT while the dose to the spinal cord was reduced, but the differences were small. Thus, inexperienced planners could easily generate a clinically feasible plan for spine SBRT by using KBP.

• 한국사회복지학
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• 제62권3호
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• pp.83-108
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• 2010

본 연구는 고령사회 준비를 위한 현황이해 차원에서 앤더슨 모형을 이용하여 노년기 외래의료 서비스 이용궤적 및 예측요인을 살펴보고, 초기노년기와 후기노년기 간에 궤적이나 예측요인이 차이가 있는지를 살펴보는 것을 목적으로 한다. 한국복지패널의 1, 2, 3차년도 자료를 사용하여, 궤적 및 예측 요인은 잠재성장모형을 이용해서 분석하였고 연령 차이는 다중집단분석을 이용하여 분석하였다. 60세 이상 노인들은 해가 지남에 따라서 외래이용 횟수를 증가시키는 경향을 보였는데, 75세 미만의 초기 노년기의 노인들이 75세 이상의 후기노년기의 노인들 보다가 이용 횟수를 상대적으로 빨리 증가시켰다. 예측요인에 있어서는 선행요인, 자원요인, 욕구요인들의 상당수가 궤적과 유의미한 관계가 있었는데, 자원요인 보다는 욕구요인들이 의료서비스 이용궤적에 크게 영향을 주는 것으로 나타났다. 하지만 예측요인에 있어서 초기 및 후기 노년기 사이에 큰 차이는 없었다. 결과를 토대로 연구의 의의 및 함의를 논의하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6369-6373
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• 2013

Background: Gastric cancer is one of the most common causes of cancer deaths all over the world and the most important reason for its high rate of death is its belated diagnosis at advanced stages of the disease. Events occur in patients which are regarded not only as themselves factors affecting patients' survival but also which can be affected by other factors. This study was designed and implemented aiming to identify these events and to investigate factors affecting their occurrence. Materials and Methods: Data from 330 patients with gastric cancer undergoing surgery at the Iran Cancer Institute from 1995-1999 were analyzed. The survival time of these patients was determined after surgery and the effects of various factors including demographic, diagnostic and clinical as well as medical, and post-surgical varuiables on the occurrence of death hazard without relapse, hazard of relapse, and death hazard with a relapse were assessed. Results: The median survival time for these patients was 16.3 months and the 5-year survival rate was 21.6%. Based on the results of multi-state model, age and distant metastases affected relapse whereas disease stage, type and extent of surgery, lymph nodes metastases, and number of renewed treatments affected death hazard without relapse. Moreover, age, type and extent of surgery, number of renewed treatments, and liver metastases were identified as factors affecting death hazard in patients with relapse. Conclusions: Most cancer studies pay heed to factors which have effect on death occurrence, but some events occur which should be taken into consideration to better describe the natural process of the disease and provide researchers with more accurate data.