• 대한수의학회지
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• 제45권2호
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• pp.223-231
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• 2005

A quantitative risk assessment tool was used to provide estimates of the probability that foot-and-mouth (FMD) virus-contaminated, smuggled animal products are fed to susceptible swine in Korea. Sensitivity analyses were conducted to attempt to distinguish between parameter uncertainty and variability, using different assumptions on the effect of cooking at home, the effect of the fresh meat, and the effect of heat treatment at garbage processing facility. The median risk estimate was about 20.1% with a mean value of 27.4%. In a scenario regarding all beef and pork were considered as fresh meat the estimated median risk was 3.4%. The risk was greatly dependent on the survival parameters of the FMD virus during the cooking or heat treatment at garbage processing facility. Uncertainty about the proportion of garbage that is likely contaminated with FMD had a major positive influence on the risk, whereas conversion rate representing the size of a load had a major negative effect. This model was very useful in assessing the risk explored. However, the model also requires enhancements, such as the availability of more accurate data to verify the various assumptions considered such as FMD prevalence in a specific country, proportion of garbage which is recycled as feed, proportion of food discarded as garbage. Other factors including the effect of selection of animals for slaughter, ante- and post-mortem inspection, the domestic distribution of the smuggled products, and susceptible animals other than pigs, are need to be taken into account in the future model development.

• 대한족부족관절학회지
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• 제16권1호
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• pp.31-37
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• 2012

Purpose: The purpose of our study is the comparison of radiological and clinical outcomes between modified distal chevron osteotomy and proximal metatarsal osteotomy for the patients who had moderate to severe hallux valgus deformity. Materials and Methods: In this retrospective study, we included 54 patients (65 feets) who underwent the operation of moderate to severe hallux valgus in our hospital from May 2007 to August 2010. Our study compares two groups. For Group 1, a modified distal chevron osteotmy and a distal soft tissue procedure were done and for Group 2, a proximal metatarsal osteotmy and a distal soft tissue procedure were done. The group 1 were 29 feets; the group 2 were 36 feets, and the average follow up was 9 months. Results: The radiological results show that the hallux valgus angle and the first-second intermetatarsal angle were significantly decreased in two groups. In each parameter, the correction of the hallux valgus angle was $19.1^{\circ}$ (Group 1) and $24.3^{\circ}$ (Group 2), the correction of the first-second intermetatarsal angle was $9.6^{\circ}$ (Group 1) and $10.3^{\circ}$ (Group 2). Shortening of the first metatarsal length was 0.87 mm (Group 1) and 0.77 mm (Group 2). There are no significant clinical results (American Orthopaedic Foot and Ankle Society score, AOFAS score) in two groups. Conclusion: It is thought that a modified distal chevron osteotomy and a distal soft tissue procedure are a considerable operative treatment of moderate to severe hallux valgus deformity because of the similar cilinical results, more simple operative techniques, and less complications than a proximal metatarsal osteotomy.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.928-931
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• 1996

It is necessary to develop the simulator for the test of stability and torque before the walking experiment of biped robot, because a robot may be damaged in an actual experiment. This thesis deals with the development of three-dimensional simulator for improving efficiency and safety during development and experimentation. The simulator is composed of three parts-solving dynamics, rendering pictures and communicating with the robot. In the first part, the D-H parameter and parameter of links can be loaded from the file and edited in the program. The results are obtained by using the Newton-Euler method and are stored in the file. Through the above process, the proper length of link and driving force can be found by using simulator before designing the robot. The second part is organized so that the user can easily see a specific value or a portion he wants by setting viewing parameters interactively. A robot is also shown as a shaded rendering picture in this part. In the last part, the simulator sends each desired angle of joints to the robot controller and each real angle of joints is taken from the controller and passed to the second part. The safety of the experiment is improved by driving the robot after checking whether the robot can be actuatable or not and whether the ZMP is located within the sole of the foot or not for a specific gait. The state of the robot can be easily grasped by showing the shaded rendering picture which displays the position of the ZMP, the driving force and the shape of robot.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.285-291
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• 2020

제조 산업에서 인력은 로봇으로 대체되지만 전문 기술은 데이터 변환이 어려워 산업용 로봇에 적용이 불가능하다. 이는 비전 기반의 모션 인식 방법으로 데이터 확보가 가능하나 이미지 데이터에 따라 판단 값이 달라질 수 있다. 따라서 본 연구는 비전 방법을 사용해 사람의 자세를 추정 시 영향을 미치는 인자를 고려해 정확성 향상 방법을 찾고자 한다. 비전 방법 중 OpenPose의 3가지 모델 MPII, COCO 및 COCO + foot을 사용했으며, CNN(Convolutional Neural Networks)을 사용한 OpenPose 구조에서 얼굴 가림 및 이미지 전처리에 미치는 영향을 확인하고자 액세서리의 유무, 이미지 크기 및 필터링을 매개 변수로 설정했다. 각 매개 변수 별 이미지 데이터를 3 가지 모델에 적용해 실제 값과 예측 값 사이 거리 오차와 PCK (Percentage of correct Keypoint)로 영향도를 판단했다. 그 결과 COCO + foot 모델은 3 가지 매개 변수에 대한 민감도가 가장 낮았다. 또한 이미지 크기는 50% (원본 3024 × 4032에서 1512 × 2016로 축소) 이상 비율이 가장 적절하며, MPII 모델만 emboss 필터링을 적용할 때 거리 오차 평균이 최대 60pixel 감소되어 향상된 결과를 얻었다.

• 전자공학회논문지A
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• 제31A권7호
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• pp.47-54
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• 1994

The propagation prediction within a cell coverage in land mobile radio service is very important. The propagation loss is presented in a A+B logS110TR form, where both A and B are the parameter as function of the frequency and the antenna height and R is the distance of between base and mobile station. The propagation prediction is Cheju area is not easy, because a great number of peaks are found here and there at the foot of the Hanla Mt. The characteristics of radio propagation in Cheju area are measured for the Seorum transmitter site. The formular of correction which is regard to the configuration of the ground is presented, and the predicted values are compared with the measured one.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.273-280
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• 2000

Building structures which are in need of large open space make the damping effect of the structures decrease greatly. Assembly and office buildings with a lower natural frequency have a higher possibility of experiencing excessive vibration induced by human activities. These excessive vibration make the residents uncomfortable and the serviceability deterioration. The loads induced by human activities were classified into two types. First type is in place loads as like jumping, foot stamping and body bouncing. The other type is moving loads as like walking, running and dancing. A series of laboratories experiments had been conducted to study the dynamic loads induced by human activities, The earlier works were mainly concerned to parameters study of dynamic loads as like activity type, weight, sex, surface condition of structure and etc. In this paper, we have measured directly the walking loads by using the platform. And we have evaluated and analyzed load-time history of walking loads. One of the most important parameter is pacing rate (walking speed) in the walking loads. The difference between the maximum value and minimum value of walking loads depends on the walking speed.

• Annals of Clinical Neurophysiology
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• 제8권2호
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• pp.146-151
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• 2006

Background: Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve within fibrous tunnel on the medial side of the ankle. The most common cause of TTS is idiopathic. This is a retrospective study to define the electrophysiological characteristics of idiopathic TTS. Methods: We reviewed the medical and electrophysiological records of consecutive patients with foot sensory symptoms referred to electromyography laboratory. Inclusion of patients was based on clinical findings suggestive of TTS. Among them, patients with any other possible causes of sensory symptoms on the foot were excluded. Control data were obtained from 19 age-matched people with no sensory symptoms or signs. Routine motor and sensory nerve conduction study (NCS) including medial plantar nerve (MPN) using surface electrodes were performed. Result: Twenty one patients (13 women, 8 men, 9 unilateral, 12 bilateral) were enrolled to have idiopathic TTS (total 31 feet). Tinel's sign was positive in 16 feet (51.6%) of TTS and four feet (10.5%) in control group. The statistically significant electrophysiological parameter was difference of sensory conduction velocity (SCV) between sural nerve and MPN. Amplitude of sensory nerve action potential and SCV of MPN were not different significantly between idiopathic TTS feet and controls. Conclusion: Bilateral development in idiopathic TTS was more common. Tinel's sign and difference of SCV between sural nerve and MPN may be helpful for the diagnosis of idiopathic TTS.

• 대한족부족관절학회지
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• 제18권4호
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• pp.195-201
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• 2014

Purpose: The purpose of this study is to develop guidelines for clinical trial of the total ankle replacement system for premarket approval. Materials and Methods: We selected and analyzed nine peer-reviewed articles whose quality had been proven in a previous phase. Two investigators extracted parameters for guideline criteria, including number of cases, patient age, follow-up period, failure rate, radiographic osteolysis rate, residual pain rate, and percentage of satisfaction. In addition, the inclusion and exclusion criteria were analyzed and developed. Results: Eight level IV studies and one level II study were included. The average number of cases was 159 cases and the mean patient age was 63.5 years. The mean follow-up period was 4.2 years, ranging from two to nine. The average failure rate of total ankle replacement in mid- to long-term follow-up was approximately 13% (2%~32.3%). The rate of osteolysis was approximately 18%. Residual pain was common (21.4%~46%), but overall patient satisfaction was approximately 85.6% (67.5%~97%). Conclusion: The results could be used as criteria for designing the clinical studies, such as number of cases, patient age (over 60 years), and follow-up period (minimum two years). The clinical scoring system and 36-item short form health survey (SF-36) was the most commonly used method for clinical evaluation for total ankle arthroplasty. In addition, the overall results, including failure rate, osteolysis rate, and patient satisfaction, could be used as a parameter of guidelines for premarket approval.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.285-288
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• 2001

Hypereutectic Al-25Si-X alloys, expected to be applied to the cylinder-liner-part of the engine-block of an automobile due to the excellent wear resistance, low density and low thermal expansion coefficient has been fabricated through a spray forming process. The obtained microstructure of the hypereutectic Al-25Si-X alloy appeared to consist of Al matrix and equiaxed Si particles of average diameter of $5-7{\mu}m$. To characterize the deformation behavior of this alloy, a series of load relaxation and compression tests have been conducted at temperatures ranging from RT to $500^{\circ}C$. The strain rate sensitivity parameter (m) of this alloy has been found to be very low (0.1) below foot and reached 0.2 at $500^{\circ}C$. During the deformation above 300'c in compression, strain softening has been observed. The diagram of extrusion pressure vs. ram-speed has been constructed, providing the extrusion condition of Al-25Si-X alloys.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.576-583
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• 2000

A robust position control using a sliding mode controller is adopted for the stable dynamic walking of the biped. For the biped robot that is modeled with 14 degrees of freedom rigid bodies using the method of the multibody dynamics, the joint angles for simulation are obtained by the velocity transformation matrix using the given Cartesian foot and trunk trajectories. Hertz force model and Hysteresis damping element which is used in explanation of the energy dissipation during contact with ground are used for modeling of the ground reactions during the simulation. By the obtained that forces which contains highly confused noise elements and the system modeling uncertainties of various kinds such as unmodeled dynamics and parameter inaccuracies, the biped system will be unstable. For that problems, we are adopting a nonlinear robust control using a sliding mode controller. Under the assumption that the esimation error on the unknown parameters is bounded by a given function, that controller provides a successful way to preserve stability and achieve good performance, despite the presence of strong modeling imprecisions or uncertainties.