• 대한치과기공학회지
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• 제34권4호
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• pp.473-482
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• 2012

Purpose: The purpose of this study was to investigate the stress distribution of the surrounding tissues according to 3 proximal plate types of the RPI clasp. Methods: The removeable partial denture which mandibular right and left second premolars and mandibular molars were lost was attached to a three dimensional photo elastic epoxy resin model. Then 120N of vertical load was applied. After 3-dimensional photoelastic stress analysis was used to record the isochromatic fringe patterns. Results: Kratochvil type guiding plane exhibited little uniform stress distribution on load center and alveolar ridge, but higher stress concentration on buccal surface of second premolar. Krol type guiding plane exhibited the stress concentration on the front of load center and relatively higher stress concentration on buccal surface of first premolar. However, this type had no effect on canine. Researcher type guiding plane showed the stress concentration on second premolar and molar, but the little stress distribution on first premolar. Conclusion: In all types, excessive stress concentration was appeared and three types were not significant different.

• 치과방사선
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• 제24권2호
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• pp.439-450
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• 1994

Recently, the digital image was introduced into radiological image. The digital image has the power of contrast enhancement, histogram control, and other digitally enhancement. At the point of the resolution, periapical radiograph is superior to the digital image, but enhanced digital procedure improves the diagnostic ability of the digital image. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries in conventional radiographs, digital radiographs and enhanced digital radiographs (histogram specification). ROC (Receiver Operating Characteristic) analysis and paired t-test were used for the evaluation of detectability, and following results were acquired: 1. The mean ROC area of conventional radiographs was 0.9274. 2. The mean ROC area of unenhanced digital image was 0.9168. 3. The mean ROC area of enhanced digital image was 0.9339. 4. The diagnostic ability of three imaging methods was not significant difference(p>0.05). So, the digital images had similar diagnostic ability of artificial proximal caries to conventional radiographs. If properly enhanced digital image, it may be superior to conventional radiographs.

• The Journal of Korean Physical Therapy
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• 제29권2호
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• pp.95-100
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• 2017

Purpose: This study aimed to evaluate the changes in dorsiflexion and balance following proximal and distal tibiofibular joint manipulation in individuals with a history of lateral ankle sprain (LAS). Methods: Fifteen participants with a history of unilateral LAS, exhibiting a restriction in ankle dorsiflexion were included in this study. LAS ankle received a manipulation to the proximal and distal tibiofibular joint, while the opposite control ankle received no manipulation intervention. The outcome measures included ankle dorsiflexion and balance. Ankle dorsiflexion was measured using weight-bearing lunge test. Static and dynamic balances were measured using the overall, anterioposterior, and mediolateral balance index via the biodex balance system. Measurements were obtained prior to and following manipulation. Results: This study showed that ankle dorsiflexion and dynamic balance were improved following the manipulation compared to those prior to the manipulation (p<0.05). There was no significant change in static balance (p>0.05). Conclusion: The joint manipulation technique applied to the ankle of those with a history of LAS appears to improve ankle dorsiflexion and dynamic balance. This suggest that a manipulation to the proximal and distal tibiofibular joint could be provided as preliminary data regarding the prophylactic effects of recurrent LAS.

• Clinics in Shoulder and Elbow
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• 제3권1호
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• pp.20-25
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• 2000

Purpose : To evaluate functional results and study factors influencing results after humeral hemiarthroplasty for comminuted fractures of the proximal humerus. Materials and Methods: We reviewed 12 patients with average follow-up period of 23 months(12 to 42). The proximal humeral fractures consisted of one anatomical neck fracture, five three-part and six four-part fractures or fracture-dislocations. Constant score and Compito et al' evaluation system were used for clinical assessment. Statistical analysis was done with the Wilcoxon test. Results: Six cases of anatomical neck, three-part fractures or fracture-dislocations showed 61 points on the average Constant score and three unsatisfactory results on the Compito et al' evaluation; Six of four-part fractures or fracture-dislocations showed 51 points and three unsatisfactory results. There were 59(two unsatisfactory) for five non-associated dislocation and 53(four unsatistactory) for seven associated dislocation; 66(one unsatisfactory) for three under 60 years and 41(five unsatisfactory) for nine over 60 years; 67(two unsatisfactory) for seven tuberosity union and 41(four unsatisfactory) for five tuberosity non-union or resorption; 58(four unsatisfactory) for ten early operation within two weeks and 43(all unsatisfactory) for two delayed operation; and 18(unsatisfactory) for one case of a accompanied rotator cuff tear. Conclusion: We concluded that tuberosity union was important factor influencing the results. Also, we thought that age, timing of operation and accompanied rotator cuff tear could be influenced to results.

• 한국게임학회 논문지
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• 제19권3호
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• pp.5-14
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• 2019

게임 서버는 분산 서버를 기본으로 하고 있다. 분산 게임서버는 서버의 작업 부하를 분산하기 위한 일련의 알고리즘에 의해 각 게임 서버의 부하를 일정하게 나누어서 클라이언트들의 요청에 대한 서버의 응답시간 및 서버의 가용성을 효율적으로 관리한다. 본 논문에서는 시뮬레이션 환경에서 기존 연구 방식인 Greedy 알고리즘과, Reinforcement Learning의 한 줄기인 Policy Gradient 중 PPO(Proximal Policy Optimazation)을 이용한 부하 분산 Agent를 제안하고, 시뮬레이션 한 후 기존 연구들과의 비교 분석을 통해 성능을 평가하였다.

• Clinics in Shoulder and Elbow
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• 제25권4호
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• pp.282-287
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• 2022

Background: Muscular forces drive proximal humeral fracture deformity, yet it is unknown if arm position can help mitigate such forces. Our hypothesis was that glenohumeral abduction and humeral internal rotation decrease the pull of the supraspinatus and subscapularis muscles, minimizing varus fracture deformity. Methods: A medial wedge osteotomy was performed in eight cadaveric shoulders to simulate a two-part fracture. The specimens were tested on a custom shoulder testing system. Humeral head varus was measured following physiologic muscle loading at neutral and 20° humeral internal rotation at both 0° and 20° glenohumeral abduction. Results: There was a significant decrease in varus deformity caused by the subscapularis (p<0.05) at 20° abduction. Significantly increasing humeral internal rotation decreased varus deformity caused by the subscapularis (p<0.05) at both abduction angles and that caused by the supraspinatus (p<0.05) and infraspinatus (p<0.05) at 0° abduction only. Conclusions: Postoperative shoulder abduction and internal rotation can be protective against varus failure following proximal humeral fracture fixation as these positions decrease tension on the supraspinatus and subscapularis muscles. Use of a resting sling that places the shoulder in this position should be considered.

• 대한족부족관절학회지
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• 제12권1호
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• pp.20-25
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• 2008

Purpose: The purpose of this study is comparison of radiological and clinical outcomes between proximal metatarsal osteotomy and distal chevron osteotomy for the correction of hallux valgus. Materials and Methods: In this retrospective study, we included subjects who underwent the correction of hallux valgus in our institution between March 2001 and August 2006, with a minimum follow-up of 12 months. The group of proximal metatarsal osteotomy was 23 patients (34 feet); the group of distal chevron osteotomy was 20 patients (26 feet). The group of proximal metatarsal osteotomy was composed of 26 severe cases (76.5%) and 8 moderate cases (23.5%); the group of distal chevron osteotomy was composed of 13 severe cases (50.0%) and 13 moderate cases (50.0%). Results: Compared to preoperative values, the hallux valgus angle, the first-second intermetatarsal angle and the distance of first-fifth metatarsal head were significantly decreased in two groups (p<0.05). In each parameter, the hallux valgus angle was decreased 66.3% (proximal metatarsal osteotomy) versus 49.6% (distal chevron osteotomy), which were significant (p=0.037). The first-second intermetatarsal angle and the distance of first-fifth metatarsal head were not significant. Mayo clinic forefoot scoring system (FFSS) score was significantly improved in two groups (p<0.05). The ratio of improvement was not significant (p=0.762). In severe group, hallux valgus angle and the first-second intermetatarsal angle was significantly decreased in proximal metatarsal osteotomy group compared to distal chevron osteotomy group (p<0.05), but the difference of the distance of first-fifth metatarsal head and FFSS score was not significant in both groups. In moderate group, the difference of all parameters was not significant in both groups. Conclusion: Although both proximal metatarsal osteotomy and distal chevron osteotomy showed satisfactory result in FFSS, proximal metatarsal osteotomy was more proper operative technique than distal chevron osteotomy in severe group, because of superiority of correction in radiological parameters.

• 대한소아치과학회지
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• 제31권2호
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• pp.323-330
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• 2004

본 연구는 레이저 형광을 치아의 인접면에 적용하여 임상에서 초기 인접면 우식증의 감별에 레이저의 이용가능성을 평가하는데 그 목적이 있다. 염료와 레이저 형광법의 인접면 우식증 탐지효과를 평가하기 위해 조선대학교 소아치과에 내원한 아동 중 유구치의 탈락이 없으며 인접면의 수복치료를 받지 않은 $3{\sim}9$세 사이의 어린이 30명을 대상으로 하였으며, 시진, 교익 방사선사진, 레이저 형광법, 염료와 레이저 형광법을 이용해 관찰한 결과를 비교하여 다음과 같은 결과를 얻었다. 1. 인접면 우식증의 교익 방사선 사진검사와 시진, 레이저 형광법, 염료와 레이저 형광법 사이에서 모두 높은 상관 관계(r=0.725-0.911)를 보였다(p<0.05). 2. 인접면 우식증의 교익 방사선사진 검사와 각 검사법간의 일치도(kappa치)는 각각 시진이 0.451 레이저 형광법이 0.683, 염료와 레이저 형광법이 0.772로 가장 일치도가 높았다. 이상의 결과를 종합해 보면 교익 방사선사진 검사법과 염료와 레이저 형광법 검사 수치의 상관관계가 진단학적 일치도가 높아 레이저 형광법이 향후 교익방사선 사진 검사법을 대치 할 수 있는 인접면 우식증 검사법으로 사료된다.

• Nonlinear Functional Analysis and Applications
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• 제28권1호
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• pp.175-203
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• 2023

In this paper, we study an iterative algorithm that is based on inertial proximal and contraction methods embellished with relaxation technique, for finding common solution of monotone variational inclusion, and fixed point problems of pseudocontractive mapping in real Hilbert spaces. We establish a strong convergence result of the proposed iterative method based on prediction stepsize conditions, and under some standard assumptions on the algorithm parameters. Finally, some special cases of general problem are given as applications. Our results improve and generalized some well-known and related results in literature.

• 대한족부족관절학회지
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• 제11권1호
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• pp.39-44
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• 2007

Purpose: The authors intended to analyze the operative results of moderate hallux valgus with proximal chevron metatarsal osteotomy and distal soft tissue procedure. Materials and Methods: Seventy feet of fifty-seven patients were followed for more than 1 year after the proximal chevron metatarsal osteotomy. The mean age was 47.2 years, and the mean follow up period was 2 years and 3 months. Clinically preoperative and postoperative AOFAS MP-IP scale and satisfaction after the surgery were analyzed. Radiologically hallux valgus angle, hallux valgus interphalangeal angle, the intermetatarsal angle and sesamoid position before and after the operation were analyzed. Results: Additional Akin osteotomy was performed 48 out of 70 feet. Clinically AOFAS MP-IP scale was increased from 60.4 points preoperatively to 89.8 points postoperatively. Ninety-four percents of the patients were satisfied with the results. Radiologically hallux valgus angle was decreased from $34.8^{\circ}$ preoperatively to $12.8^{\circ}$ postoperatively. The intermetatarsal angle was decreased from $15.7^{\circ}$ preoperatively to $8.0^{\circ}$ postoperatively. Hallux valgus interphalangeal angle was increased from $7.4^{\circ}$ preoperatively to $9.8^{\circ}$ postoperatively. There were 3 recurrences, 1 hallux varus and 3 minor wound infections. There were no nonunion or malunion of the 1st metatarsal. Conclusion: Proximal chevron metatarsal osteotomy with distal soft tissue procedure and additional Akin osteotomy appears to be safe and satisfactory procedure.