• Title/Summary/Keyword: proximal method

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Prognostic Value of Esophageal Resectionline Involvement in a Total Gastrectomy for Gastric Cancer (위전절제술 시 식도측 절제연 암 침윤의 예후적 가치)

  • Kwon, Sung-Joon
    • Journal of Gastric Cancer
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    • v.1 no.3
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    • pp.168-173
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    • 2001
  • Purpose: A positive esophageal margin is encountered in a total gastrectomy not infrequently. The aim of this retrospective review was to evaluate whether a positive esophageal margin predisposes a patient to loco-regional recurrence and whether it has an independent impact on long-term survival. Materials and Methods: A retrospective review of 224 total gastrectomies for adenocarcinomas was undertaken. The Chisquare test was used to determine the statistical significance of differences, and the Kaplan-Meier method was used to calculate survival rates. Significant differences in the survival rates were assessed using the log-rank test, and independent prognostic significance was evaluated using the Cox regression method. Results: The prevalence of esophageal margin involvement was $3.6\%$ (8/224). Univariate analysis showed that advanced stage (stage III/IV), tumor size ($\geq$5 cm), tumor site (whole or upper one-third of the stomach), macroscopic type (Borrmann type 4), esophageal invasion, esophageal margin involvement, lymphatic invasion, and venous invasion affected survival. Multivariate analysis demonstrated that TNM stage, venous invasion, and esophageal margin involvement were the only significant factors influencing the prognosis. All patients with a positive esophageal margin died with metastasis before local recurrence became a problem. A macroscopic proximal distance of more than 6 cm of esophagus was needed to be free of tumors, excluding one exceptional case which involved 15 cm of esophagus. Conclusion: All of the patients with a positive proximal resection margin after a total gastrectomy had advanced disease with a poor prognosis, but they were not predisposed to anastomotic recurrence. Early detection and extended, but reasonable, surgical resection of curable lesions are mandatory to improve the prognosis.

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The Usefulness of the Artificial Nail for Treatment of Fingertip Injuries (손가락끝 손상의 치료 시 인조손톱의 유용성)

  • Choi, Hwan-Jun;Kwon, Joon-Sung;Tark, Min-Seong
    • Archives of Plastic Surgery
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    • v.37 no.6
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    • pp.788-794
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    • 2010
  • Purpose: The fingertip is the most commonly injured part of the hand and its injury frequently results in avulsion or crushing of a segment of the nail bed and fracture of the distal phalangeal bone. Restoration of a flat and smooth nail bed is essential for regrowth of a normal nail, which is important not only for cosmetic reasons but also for tactile capability of the fingertip. It is also anatomical reduction of the distal phalanx to promote patient's cosmetics and prevent nail bed deformity. Absence or no replacement of the nail plate results in obliterated proximal skin fold. When the avulsed nail plate cannot be returned to its anatomic position or when it is absent, we use a synthetic material for splinting the nail bed and alternative reductional method for distal phalangeal bone fracture, especially, instead of hardwares. Methods: From January of 2006 to June of 2009, a total of ten patients and fourteen fingers with crushing or avulsion injuries of the fingertip underwent using the artificial nails for finger splint. We shaped artificial nails into the appropriate sizes for use as fingernail plates. We placed them under the proximal skin fold and sutured to the fold proximally and to the lateral and medial edges of the nail bed or to the distal fingertip. Our splints were as hard as K-wire and other fixation methods and more similar to anatomic nail plates. Artificial nails were kept in place for at least 3 weeks. Results: No artificial nail related complication was noted in any of the ten cases. No other nail fold or nail bed complications were observed, except for minor distal nail deformity because of trauma. Conclusion: In conclusion, in order to secure the nail bed after injury and reduce the distal phalangeal bone fracture, preparing a nail bed splint from a artificial commercial nail is a cheap and effective method, especially, for crushed or avulsion injuries of the fingertip.

Evaluation of adjacent tooth displacement in the posterior implant restoration with proximal contact loss by superimposition of digital models

  • Jo, Deuk-Won;Kwon, Min-Jung;Kim, Jong-Hee;Kim, Young-Kyun;Yi, Yang-Jin
    • The Journal of Advanced Prosthodontics
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    • v.11 no.2
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    • pp.88-94
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    • 2019
  • PURPOSE. This study was conducted to investigate patterns of adjacent tooth displacement in the posterior implant with interproximal contact loss (ICL) by 3-D digital superimposition method. MATERIALS AND METHODS. Posterior partially edentulous patients, restored with implant fixed partial prostheses before 2011 and suffered from food impaction of ICL between 2009 and 2011, were included. Two dental casts, at the time of delivery and at the time of food impaction in a same patient, was converted into 3-D digital models through scanning and superimposition was performed to assess chronologic changes of the dentition. Directions of tooth displacement were evaluated and the amount of ICL was calculated. Correlations between the amount of ICL and elapsed time, or between the amount of ICL and age after function, were assessed at a significance level of P<.05. RESULTS. A total number of 13 patients (8 males, 5 females) with a mean age of $65.76{\pm}9.94years$ and 17 areas (4 maxillae, 13 mandibles) were included in this retrospective study. Teeth adjacent to the implant restoration showed complex displacements but characteristic tendency according to the location of the arch. The mean amount of ICL was $0.33{\pm}0.14mm$. Elapsed time from function to ICL was $61.47{\pm}31.27months$. There were no significant differences between the amount of ICL and elapsed time, or age (P>.05). CONCLUSION. Natural teeth showed various directional movements to result in occlusal change in the arch. The 3-D superimposition of chronologic digital models was a helpful method to analyze the changes of dentition and individual tooth displacement adjacent to implant restoration.

Design and Implementation of Reinforcement Learning Agent Using PPO Algorithim for Match 3 Gameplay (매치 3 게임 플레이를 위한 PPO 알고리즘을 이용한 강화학습 에이전트의 설계 및 구현)

  • Park, Dae-Geun;Lee, Wan-Bok
    • Journal of Convergence for Information Technology
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    • v.11 no.3
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    • pp.1-6
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    • 2021
  • Most of the match-3 puzzle games supports automatic play using the MCTS algorithm. However, implementing reinforcement learning agents is not an easy job because it requires both the knowledge of machine learning and the way of complex interactions within the development environment. This study proposes a method in which we can easily design reinforcement learning agents and implement game play agents by applying PPO(Proximal Policy Optimization) algorithms. And we could identify the performance was increased about 44% than the conventional method. The tools we used are the Unity 3D game engine and Unity ML SDK. The experimental result shows that agents became to learn game rules and make better strategic decisions as experiments go on. On average, the puzzle gameplay agents implemented in this study played puzzle games better than normal people. It is expected that the designed agent could be used to speed up the game level design process.

Finite element analysis of the crack emanating to cavity in the bone cement of the hip prosthesis

  • Benouis Ali;Zagane Mohammed El Sallah;Moulgada Abdelmadjid;Ait Kaci Djafar;Zahi Rachid;Cherfi Mohamed
    • Structural Engineering and Mechanics
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    • v.92 no.3
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    • pp.297-306
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    • 2024
  • The analysis of elliptical cracks emanating from cavities in polymethyl-methacrylate (PMMA) surgical cement is crucial for understanding loosening in total hip prostheses, as cement failure is a primary cause of this issue. Understanding fracture mechanismsis vital for improving the durability of cemented prostheses. Predicting crack propagation paths can help identify high-risk areas using medical imaging. This study focuses on the behavior of cracks emanating from cavities within the orthopedic cement, using a realistic model. The crack behavior is analyzed in terms of the evolution of stress intensity factors (SIFs) in Modes I, II, and III, applying the maximum tangential stress criterion. The fracture analysis considers the crack size relative to the cavity, its orientation, and its location in the orthopedic cement. The finite element method specifically examines elliptical cracks along the cement, focusing on the effect of the distance between cracks emanating from cavities and nearby defects on SIFs. The orientation of these cracks significantly influences SIF magnitudes and modes, affecting the direction and stability of crack propagation. The study reveals that the proximal lateral part experiences the highest stresses, with a notable increase in SIFs in Modes I and II, particularly where crack interaction occurs. The proximal medial part follows, while the distal part is predominantly subjected to compressive stresses.

Study of the Center of Gravity in the Human Body and each Segment (인체 중심과 분절 중심에 대한 연구)

  • Chung Hyung-Kuk;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.5 no.1
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    • pp.61-69
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    • 1993
  • It was performed to encourage for Physical Therapist to apply the theory of center of the human body and segments in clinical situations. This study was investigated literarily on center of the human body and segments. Methods which search for the center-2 types, that is, method using reaction broad and segmental method-was suggested. The center location difference of gravity in human body depends on individual character. Generally, the center location is in kent of 2nd sacrum, that is, at $55\%$ of height from foot. The center of each segment is on 'link'. In the first place we must how the weight of segment we can search for the center easily. Mean segment coater location of extremities is at $42.33\%$ from each proximal end, and mean center of head and trunk lies at $45\%$.

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The Experimental Study on the Animal Stroke Model of Oriental Medicine (한의학적 중풍 동물 모델 설정을 위한 실험적 연구)

  • 채한;이현삼;홍무창
    • The Journal of Korean Medicine
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    • v.20 no.4
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    • pp.82-92
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    • 2000
  • The purpose of the present study was to explore the proper method for animal stroke model of Oriental medicine To this end, brain ischemia was induced by distal middle cerebral artery occlusion(dMCAO) and proximal middle cerebral artery occlusion(pMCAO) and evaluated with the method of Triphenyl Tetrazolium Chloride (TTC) staining and Swimming Behavior Test. Results demonstrated that first, infarct size and volume of pMCAO group were significantly bigger that those of dMCAO group. Second, analysis of swimming behavior test revealed that the percentage of left turning angles of pMCAO was significantly bigger than that of dMCAO. Third, during swimming behavior test, there were peculiar traces of small successive circles that represent motor dysfunction and conscious disturbance among dMCAO group. The results of the study thus indicate that non-invasive intraluminal method of pMCAO was the appropriate animal stroke model for Oriental medicine in the light of brain ischemia as hemiplesia and conscious disturbance.

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Adaptive Fast Calibration Method for Active Phased Array Antennas using PPO Algorithm (PPO 알고리즘을 이용한 능동위상배열안테나 적응형 고속 보정 방법)

  • Sunge Lee;Kisik Byun;Hong-Jib, Yoon
    • Journal of IKEEE
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    • v.27 no.4
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    • pp.636-643
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    • 2023
  • In this paper, a high-speed calibration method for phased array antennas in the far-field is presented A max calibration, which is a simplification of the rotating-element electric-field vector (REV) method that calibrates each antenna element only through received power, and a method of grouping calibrations by sub-array unit rather than each antenna element were proposed. Using the Proximal Policy Optimization (PPO) algorithm, we found a partitioning optimized for the distribution of phased array antennas and calibrated it on a subarray basis. An adaptive max calibration method that allows faster calibration than the conventional method was proposed and verified through simulation. Not only is the gain of the phased array antenna higher while calibration is being made to the target, but the beam pattern is closer to the ideal beam pattern than the conventional method.

Influence of porosity on the behavior of cement orthopaedic of total hip prosthesis

  • Ali, Benouis;Boualem, Serier;Smail, Benbarek
    • Biomaterials and Biomechanics in Bioengineering
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    • v.2 no.4
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    • pp.197-206
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    • 2015
  • This paper presents three-dimensional finite element method analyses of the distribution of equivalents stress of Von Mises. Induced around a cavity located in the bone cement polymethylmethacrylate (PMMA). The presences and effect of its position in the cement was demonstrated, thus on the stress level and distribution. The porosity interaction depending on their positions, and their orientations on the interdistances their mechanical behaviour of bone cement effects were analysed. The obtained results show that micro-porosity located in the proximal and distal zone of the prosthesis is subject to higher stress field. We show that the breaking strain of the cement is largely taken when the cement, containing the porosities very close adjacent to each other.

An Approach to Implementing Distributed Optimal Power Flow (최적조류계산의 분산처리기법에 관한 연구)

  • Kim, Ho-Woong;Kim, Bal-Ho;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.182-186
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    • 1997
  • This paper presents a mathematical approach to implementing distributed optimal power flow (OPF), wherein a regional decomposition technique is adopted to parallelize the OPF. Three mathematical decomposition coordination methods are introduced firs to implement the proposed distributed scheme: the Auxiliary Problem Principle (APP), the Predictor-Corrector Proximal Multiplier Method (PCPM), and the Alternating Direction Method (ADM). Then two alternative schemes for modeling distributed OPF are introduced; the Dummy Generator-Dummy Generator (DGDG) scheme and Dummy Generator-Dummy Load (DGDL) scheme. We present the mathematical analyses of the proposed approach, and demonstrate the approach on several test, systems, including IEEE Reliability Test Systems and parts of the ERCOT (Electric Reliability Council of Texas) system.

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