• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.609-615
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• 2012

In LSP (laser shock peening) treatment, the laser source geometries when the laser beam strikes the metal target area are diverse. The laser spot geometry affects the residual stress field beneath the treated surface of the metallic materials, which determines the characteristics of the pressure pulse. In this paper, detailed finite-element (FE) simulations on laser shock peening have been conducted in order to predict the magnitude and of the residual stresses and the depth affected in Inconel alloy 600 steel. The residual stress results are compared for circular, rectangular, and elliptical laser spot geometries. It is found that a circular spot can produce the maximum compressive residual stresses near the surface but generates tensile residual stresses at the center of the laser spot. In the depth direction, an elliptical laser spot produces the maximum compressive residual stresses. Circular and elliptical spots plastically affect the alloy to higher depths than a rectangular spot.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.4
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• pp.503-509
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• 2013

Carbon fiber reinforced plastics (CFRPs), a composite material, are generally vulnerable to compressive load and impact damage in a direction perpendicular to the surface of the material. In particular, during the operation of an aircraft, impact damages caused by bird collisions or falling tools reduce the strength of the aircraft structure. In this study, after impact damages were applied to CFRP specimens with various impact energies and impactor diameters, the compressive residual strength of the impact-damaged specimen was evaluated by performing a compression test. Furthermore, a prediction model for the compressive residual strength is proposed according to the variation in the impact energy by comparing the test results.

• Journal of the Korea Furniture Society
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• v.26 no.1
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• pp.61-70
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• 2015

There is an increasing trend each year in the number of subway users due to increase in the traffic volume. As the number of train service has risen, the subway drivers are given heavy work and from the same, are put at risk of mental health deterioration due to stress. As this is directly connected to safety, there is an urgent need for improvement of the situation. Therefore, as a way to appropriately relieve such stress, resting space where mental and physical energy can be recharged is necessary. Thus, this research conducted a survey of demand with subway drivers as subjects in order to provide resting space that can offer healthy rest and increase work effectiveness. 50 subway drivers were the subjects of this survey. As a result of analyzing the contents of the survey, environmental satisfaction was shown to be the lowest compared to psychological and morphological satisfaction. In the case of sleeping room, they wanted more comfortable and individual space. And the waiting room had the highest rate of usage frequency. The storage space was where the subway drivers showed the strongest attachment and was shown to be the only personal space. Most were shown to be satisfied with the outdoor space, but it had the lowest usage frequency. In addition, it is nessasery customized storage cabinet designed for subway drivers should be produced, which can effectively arrange the limited space. I hope that these direction of improvement can increase the healthy rest and work effectiveness of the locomotive engineers as it is directly being connected to the health and safety of the citizens.

• Korean Journal of Acupuncture
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• v.26 no.1
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• pp.27-40
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• 2009

Background : Qigong is an energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although qigong-neither itself nor its postulated mechanism of action-are within the paradigm of modern Western medical science, its effects on the human body could be possible. Objectives : This study aims to review the bibliography, biological responses and therapeutic effects of Qigong. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Method : The computerized Korean databases were searched from their respective inceptions up to January 2008. The search terms used were 'qi', 'qigong', 'doin', 'training', 'bioenergy', 'life nurturing' and random or Korean language terms related to qigong. Several specialized journals were also manually searched for relevant articles. Result : Since the 1990s, Qigong papers in the Korean Literature are increased. The articles on Korean traditional medicine had been published more than those on physical education or nursing etc. However, since the majority of the trials determine questionnaire, it was difficult to determine the efficacy of a specific intervention. The methodological quality of the trials was generally low (Jadad score: mean, 1.3; range, 1 to 4), questioning their reliability. Conclusions : More profound studies for Qigong are needed. Further rigorous clinical trials with more objective outcome measures that include sham procedures should be performed. Specifically, we think it should be clinical studies and qualitative research methods for evaluation are needed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1577-1584
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• 2002

This paper develops a finite element model for studying the occupant behavior and injury cofficients of a large-sized cab-over type truck. Since it does not have a room to absorb collision energy and deformation in front of the passenger compartment the deformation is directly transmitted to the passenger compartment. Moreover, since its steering column is attached on the frame, severe deformation of the frame directly affects on the steering wheel's movement. Therefore, if the occupant behavior and injury coefficients analysis is performed using a finite element model developed based on a sled test, it is very difficult to expect acquiring satisfactory results. Thus, the finite element model developing in this paper is based on the frontal crash test in order to overcome the inherent problems of the sled test based model commonly used in the passenger car. The occupant behavior and injury coefficients analysis is performed using PAM-CRASH installed in super-computer SP2. In order to validate the reliability of the developed finite element model, a frontal crash test is carried out according to a test method used fur developing truck occupant's secondary safety system in european community and japan. That is, test vehicle's collision direction is vertical to the rigid barrier and collision velocity is 45kph. Thus, measured vehicle pulses at the lower parts of the left and right B-pilla., dummy chest and head deceleration profiles, HIC(head injury criterial) and CA(chest acceleration) values, and dummy behavior from the frontal crash test are compared to the analysis results to validate reliability of the developed model.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.954-959
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• 2008

Qigong is one energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although qigong-neither itself nor its postulated mechanism of action - are within the paradigm of modern Western medical science, effects on the human body could be possible. This study aims to review the bibliography, biological responses and therapeutic effects of Qigong. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. The computerized Korean databases were searched from their respective inceptions up to January 2008. The search terms used were 'qi', 'qigong', 'doin', 'training', 'bioenergy', 'life nurturing' and random or Korean language terms related to qigong. Several specialized journals were also manually searched for relevant articles. Since the 1990s, Qigong papers in the Korean Literature is increased. Published 152 papers on Korean medicine were more than Physical education and Nursing. 78 papers published in The Journal of Korean Academy of medical Gi-gong are the best in many areas related to Korean medicine. Most people have submitted papers related to Qigong was Lee Gi-nam. The depth study for the each Qigong is needed. Specifically, I think it should be a clinical studies and qualitative research methods for evaluation are needed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2202-2211
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• 2010

The wind power prediction system is composed of a meteorological forecasting module, calculation module of wind power output and HMI(Human Machine Interface) visualization system. The final information from this system is a short-term (6hr ahead) and mid-term (48hr ahead) wind power prediction value. The meteorological forecasting module for wind speed and direction forecasting is a combination of physical and statistical model. In this system, the WRF(Weather Research and Forecasting) model, which is a three-dimensional numerical weather model, is used as the physical model and the GFS(Global Forecasting System) models is used for initial condition forecasting. The 100m resolution terrain data is used to improve the accuracy of this system. In addition, optimization of the physical model carried out using historic weather data in Jeju. The mid-term prediction value from the physical model is used in the statistical method for a short-term prediction. The final power prediction is calculated using an optimal adjustment between the currently observed data and data predicted from the power curve model. The final wind power prediction value is provided to customs using a HMI visualization system. The aim of this study is to further improve the accuracy of this prediction system and develop a practical system for power system operation and the energy market in the Smart-Grid.

• Korean Institute of Interior Design Journal
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• no.11
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• pp.45-56
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• 1997

In the process of modermization the problem of environment destruction has become a worldwide issue. And now this problem is a concern for all branches of science, including that of architectural desigv. This thesis tries to find the meaning of ecological architectural space, one that encreases the organic relationship, and communication, between architectrual space and urban environmental space, between human beings and architecture, and between human beings and their environment. As an example, we will take a look at the architectural space-design of Frei Otto, who offers diverse creative ecological architectural forms. His concept of architecture has the critical character when compared with the traditionan conventional concept of architecture. The ecological characteristics of his architectural spacedesign can be summarized as follows: The first characteristic is his ample use of natural objects in the architectural structure. An ample use of living things like trees and plants as well as of inanimate thing like water, wind as architectural elements enhances the functional efficiency of architecture. The second characteristic is its ecological architectural system, which saves energy faciliates ventilation by changing the position and direction of the building, by systematically applying the materials, and by efficiently arranging the inner space. The third characteristic is the dematerialization of architecture and the use of materials that are economical and appropriate for the circulation system of nature. The use of natural elements and recycling natural objects, makes it possible to reuse materials of the destroyed building. In short, the ecological architecture of Frei Otto, which shows the relation between human beings and architecture, presents diverse possibilities of the archtectural space as a complex natural system, which is more than a simple combination of separatge elements.

• Journal of Korean Medical classics
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• v.21 no.3
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• pp.297-306
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• 2008

Background : Gigong(氣功, Qigong) is one energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although Gigong(氣功, Qigong) - neither itself nor its postulated mechanism of action - are within the paradigm of modern Western medical science, effects on the human body could be possible. Objectives : This study aims to review the bibliography, biological responses and therapeutic effects of Gigong. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Method : The computerized Korean databases were searched from their respective inceptions up to January 2008. The search terms used were 'Gi(氣, Qi)', 'Gigong(氣功, Qigong)', 'Doin(導引)', 'Training', 'Bioenergy', 'life nurturing' and random or Korean language terms related to Gigong. Several specialized journals were also manually searched for relevant articles. Result : Since the 1990's, Gigong papers in the Korean Literature is increased. Clinical research studies are among the most control design study. Research subjects are less patient than the general public. The most common treatment disease was Musculo-skeletal disorder Conclusions : The depth study for the each Gigong(氣功, Qigong) is needed. Specifically, I think it should be a clinical studies and qualitative research methods for evaluation are needed.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.259-270
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• 2010

In this paper, a Location Information-based Gradient Routing (LIGR) algorithm is proposed for setting up routing path based on physical location information of sensor nodes in wireless ad-hoc networks. LIGR algorithm reduces the unnecessary data transmission time, route search time, and propagation delay time of packet by determining the transmission direction and search range through the gradient from the source node to sink node using the physical location information. In addition, the low battery nodes are supposed to have the second or third priority in case of forwarding node selection, which reduces the possibility of selecting the low battery nodes. As a result, the low battery node functions as host node rather than router in the wireless sensor networks. The LIGR protocol performed better than the Logical Grid Routing (LGR) protocol in the average receiving rate, delay time, the average residual energy, and the network processing ratio.