• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.4
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• pp.223-232
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• 2003

This paper presents a new method driving multiple robots to their goal position without collision. Each robot adjusts its motion based on the information on the goal location, velocity, and position of the robot and the velocity and position of the .other robots. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. The avoidability measure figures the degree of how easily a robot can avoid other robots considering the following factors: the distance from the robot to the other robots, velocity of the robot and the other robots. To implement the concept in moving robot avoidance, relative distance between the robots is derived. Our method combines the relative distance with an artificial potential field method. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. In contrast, the usual potential field method sometimes fails preventing collision or causes hasty motion, because it initiates avoidance motion later than the proposed method. The proposed method can be used to move robots in a robot soccer team to their appropriate position without collision as fast as possible.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.4
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• pp.163-171
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• 2019

PURPOSE: This study examined the incidence, location, and characteristics of sports injuries according to the position in Korean female national field hockey athletes. METHODS: Eighteen female national field hockey athletes (two goal keepers, five forwards, six midfielders, and five defenders) who trained at the national training center between January 2018 and December 2018 were enrolled. The event, position, and location of injury were recorded per IOC's daily injury reports form. The incidence of sports injuries was examined with the 95% confidence interval (CI), and the difference in the incidence of injury according to the position was presented as the rate ratio (RR). Moreover, differences in the location of sports injury according to the position were examined using χ2 tests. RESULTS: A total of 92 sports injuries occurred among field hockey players, with an incidence of 6.47 cases per 1,000 hours of training (95% CI 4.98-7.96). In addition, 29.12 cases of injuries occurred per 1,000 exposures (95% CI 23.17-35.07), and the incidence of injury was highest among the defenders, followed by forwards, midfielders, and goal keepers. The most common location of sports injury was the lower extremity, followed in order by the trunk, upper extremity, head, and neck, and there were significant differences in the location of the sports injury according to the position (p=.046). In addition, lumbar spine/lower back, thigh, ankle, lower leg, knee, and foot/toe were common sites of sports injury among female field hockey players. CONCLUSION: These results provide a baseline for predicting sports injuries in athletes during games, and would provide useful information for developing performance enhancement and injury prevention programs.

• Wind and Structures
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• v.11 no.2
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• pp.75-96
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• 2008

A better understanding of tornado-induced wind loads is needed to improve the design of typical structures to resist these winds. An accurate understanding of the loads requires knowledge of near-ground tornado winds, but observations in this region are lacking. The first goal of this study was to verify how well a CFD model, when driven by far field radar observations and laboratory measurements, could capture the flow characteristics of both full scale and laboratory-simulated tornadoes. A second goal was to use the model to examine the sensitivity of the simulations to various parameters that might affect the laboratory simulator tornado. An understanding of near-ground winds in tornadoes will require coordinated efforts in both computational and physical simulation. The sensitivity of computational simulations of a tornado to geometric parameters and surface roughness within a domain based on the Iowa State University laboratory tornado simulator was investigated. In this study, CFD simulations of the flow field in a model domain that represents a laboratory tornado simulator were conducted using Doppler radar and laboratory velocity measurements as boundary conditions. The tornado was found to be sensitive to a variety of geometric parameters used in the numerical model. Increased surface roughness was found to reduce the tangential speed in the vortex near the ground and enlarge the core radius of the vortex. The core radius was a function of the swirl ratio while the peak tangential flow was a function of the magnitude of the total inflow velocity. The CFD simulations showed that it is possible to numerically simulate the surface winds of a tornado and control certain parameters of the laboratory simulator to influence the tornado characteristics of interest to engineers and match those of the field.

• Journal of Engineering Education Research
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• v.18 no.4
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• pp.3-12
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• 2015

The purpose of this study was to develop a pre-training program of engineering college students for maximizing the effectiveness of internship or field training. To pursue this goal, literature review was conducted for data collection about college and corporate pre-training program for internship or field training and pre-training program(draft) was proposed. A questionnaire survey was conducted with engineering professors, students and graduates to identify the needs for pre-training program(draft) for internship or field training. Based on the results, the contents of pre-training program for internship or field training were composed of basic liberal arts, basic competency, real information related with corporation or job, and information exchange network. And key consideration for operating the pre-training program for internship or field training were proposed with the management department, regulation for the obligatory participation, meaningful organizing content, feedback of needs.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.22-22
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• 2000

The discoveries of high temperature superconductors received great attention due to their high critical temperatures. These materials also exhibit extremely high critical magnetic fields and high critical current density at low temperature, high magnetic field. Thus, they are the most promising materials for superconducting magnets above 20 T. In this talk, progress in the development of HTS materials and insert coils at the National High Magnetic Field Laboratory will be reviewed. In 1999, a Bi-2212 stack of double pancakes generated 3 T in a 19 T background field. These results will be reviewed in terms of implications for future systems. Individual double pancakes of Bi-2223 have also been tested and their performance will also be discused. The present goal of a 57 system will be presented and the key technical requirements for larger, higher field systems will be addressed. It will be shown that in addition to increased critical current density, improved mechanical performance (stain resistanced) is necessary for high field systems. Furthemore, improvements in the conductor n-value will improve prospects for operational systems.

• Smart Media Journal
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• v.4 no.1
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• pp.52-57
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• 2015

Currently the gamification as marketing technique has appeared in the field non-related with game, applied to game elements. The alternate reality game pulled down the boundary between the real and the virtual has come out. New trend game has shown beyond the range of the existing game. The possibility has import into online baseball simulation game. The objective of this research is the exploratory approach to build GOMS model through three subjects to the famous pro-baseball manager game. After game playing session, three subjects' utterance with game experience was recorded. We built the goal hierarchy of goal in GOMS to pro-baseball manager game to analyze the vocabulary in three subjects' utterance. We try to find the possibility of gamification in alternate reality game interacting between the real and the virtual, and demolishing them.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.3
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• pp.459-467
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• 2012

Marine aquariums are excellent venues for accomplishing the purpose of marine education, and school field trips conducted at non-formal settings continue to be an important part of K-12 education. The purpose of this study is to provide quantitative data regarding the extent and quality of marine aquarium field trips conducted by elementary school teachers in Seoul. A web survey designed to explore elementary school teachers' experiences and perspectives on aquarium field trips identified several concerns regarding Korean marine aquarium education. Discussions for both Korean aquaria's educational roles and Korean elementary schools' successful field trips to aquaria are presented with the goal of improving the quality of Korean marine aquarium education.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.269-273
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• 2000

This paper proposes a algorithm for several mobile robots navigation. There are three parts in this algorithm. First part generates robots turning angle and moving distance for goal approaching, sencond part generates robots avoiding angle and avoiding distance for static obstacles or other robots and third part adjust between robots moving distance and avoiding distance. Most simulation results of this algorithm are very effective for several mobile robots traveling in unknown field.

• Smart Structures and Systems
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• v.14 no.5
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• pp.981-1004
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• 2014

Structural control is a very broad field combining the areas of automatic control and structural engineering, with applications ranging from aerospace and mechanical engineering to building and civil infrastructure systems. In this paper, the focus is placed on civil engineering applications only. The goal is to address the issues concurring to form the scientific paradigm. As a resut, possible future directions of research into this field are identified.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.33-33
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• 1993

Among the Glycosaminoglycans (GAGs), Heparin and its fractions or fragments, obtained by several different processes, are of considerable interest .In these last few years, the goal of the researchers in this field has been finding molecular species having selective action, like for instance species having only antithrombotic activity disjointed from any anticoagulant effect, and assessing the effects of these GAGs and of other GAGs, like dermatan sulphate, not only in the field of venous or arterial thrombosis but also on cell factors like smooth muscle cell proliferation and even on aspects of antiinflammatory activity.