• 한국산업보건학회지
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• 제15권2호
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• pp.114-123
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• 2005

We analyzed the demographic and job features of 197 shipyard workers with work-related musculoskeletal disorders(WMSDs) compensated by the Industrial Accident Compensation Insurance Act, and the features of the disorders, the causes of operation and the induced behaviors. The three shipbuilding companies surveyed were located in Busan Metropolitan city and Gyungsangnam-do. The results were as follows. 1. The ages of WMSDs patients in shipyard were $43.6{\pm}8.6$ and the job tenure was $14.3{\pm}5.6$. The 40's of them was 40.1%, and the 30's was 29.4%. Patients less than 5 year-work duration were 85.3%, and ones more than 16 year-work duration 6.6%. In occupations, welders were 32.5%, pre-welders 17.3%, and setting engineers 6.6%. 2. The causes of WMSDs in shipyard were works(95.4%) and outer crash or accident shock (3.6%). Based on the standard of the NIOSH induced behaviors, the causes were awkward posture (62.9%), excessive movement(19.3%) and repetitive movement(13.7%). 3. The compensated WMSDs by body part was the highest, 36%, in the spines, 32.0% in both the upper limbs and the spines, and 14% in the upper limbs. The number of cases of WMSDs in body were 96 in the cervical, 79 in the lumbar and 72 in the shoulders. 4. As a result of chi-square test(${\chi}^2$) between diagnosis and operation in body, welding and spot welding had the most diagnoses in all parts of the body among other occupations. Chi-square test(${\chi}^2$) between diagnosis and induced behavior in body showed that awkward postures recorded the highest rate and repetitive movements was the second. 5. The most hazardous occupation was the welding(incidence rate=9.7) and the most hazardous behavior was the awkward posture.

• 산업경영시스템학회지
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• 제34권4호
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• pp.35-41
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• 2011

The purpose of this study was to examine drivers' driving behaviors and eye-movements according to driving speed and navigation- position while operation of the navigation in driving. For this purpose, two driving conditions (low-speed and high-speed) and two navigation-positions (top and bottom location of the center console) were set. Drivers' driving behaviors (speed, speed variation, coefficient of variation, and the number of collisions) and eye-movements (overall eye pattern, the average scanning time of navigation, and the number of gaze-out on the road for more 2 seconds) were measured. As a result, when the navigation was located at the bottom of the console, difficulties of lateral control was appeared in low-speed driving condition, and the that of longitudinal control was appeared in high-speed driving condition. In addition, above situation made the drivers' scanning times of navigation long, increased the number of gaze-out on the road for more 2 seconds, and made overall eye pattern monotonous. These results could be interpreted that the manipulation of the navigation at the bottom of console cause reduced attention capacity due to the cognitive load.

• 디지털융복합연구
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• 제11권10호
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• pp.123-131
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• 2013

본 연구의 목표는 초등부 자폐성장애 아동들의 적응행동 향상을 위해 적응행동기술을 지원하기 위한 스마트 콘텐츠의 개발 방향을 제시하는 것이다. 특수학교 교사 및 장애학생 교육기관 전문가들의 AHP설문을 통해 스마트 콘텐츠의 개발의 필요성 및 효과에 대한 적응행동기술의 중요도를 도출하였다. 또한 어떠한 적응행동기술 분야가 스마트 콘텐츠로 개발하기에 적합한지 앱개발 전문가들의 토론과 설문을 통해 그 중요도를 도출하였다. 분석결과 스마트 콘텐츠로 개발에 적합하고 그 효과가 높은 적응행동 기술은 언어이해, 시간이행 및 엄수, 이동기술, 옷입기, 개인위생이었다. 본 연구를 토대로 교육당국은 단편적인 교육용 스마트 콘텐츠 개발보다는 효과적이고 활용도가 높은 자폐성장애 아동들의 특성 및 특수교사나 부모의 요구에 맞는 스마트 콘텐츠 개발 및 지원체계를 구축하고자 노력해야 한다.

• 한국실내디자인학회논문집
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• 제20권3호
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• pp.143-151
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• 2011

With today's new media environment throughout Ubiquitous information innovation, live and dynamic fluid space is being created by integrating organic integration between electronic space and physical space and transplanting intelligence to materials. In other words, perception occurs in fluid space itself in a new media environment so has complicatedly organic relationship with environment and humans. In addition, emotion, time and movement have actively attempted to enter the space so designs appealing to humans' emotions are made through stimulation of synaesthetic sensory organs. This can be understood in the same context that media is eventually expansion of human body. Fluid space has characteristics of a live organism with factors such as sensor, perception and behavior so it needs to interpret perceptual system relationally and synthetically through an organic study method. This study looks into characteristics of organic perceptual system in terms of the meaning that fluid space with movements have as the sensory-perceptive subject and accordingly makes the world more sufficient as the third space, prepares a possibility to get out of limited five senses, and will develop fluid space as the organic environment making stimulation by itself.

• 한국해안해양공학회지
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• 제2권4호
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• pp.223-230
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• 1990

해상공사를 하므로써 발생하는 현탁물질은 공사 주변 환경변화에 많은 영향을 미치고 있다. 그러므로 해역에서 토사투하에 따른 탁수괴의 거동을 규명하는 것은 대단히 중요하다. 토사투하할 때 일어나는 유동은 퇴적현상에 영향을 미친다고 생각되어, 탁수괴의 낙하특성과 퇴적형상과의 관련성에 대하여 실험하였다. 탁수괴의 높이 변화, 길이 변화, 이동속도 변화, 탁수괴 선단부의 이동시간, 탁수괴의 운행계수, 현상계수, 토사의 퇴적형상에 대해서 알아보았다. 그 결과, 토사투하의 거동은 토사투하량이 투하토사 입경에 비하여 많을 경우 대기권에서 일어나는 난류 Thermal 현상과 유사하다는 것을 알았다. 따라서 토사투하시의 유체역학적 지배방정식은 난류 Thermal 이론으로 대신할 수 있다는 것을 알았다.

• 한국농촌건축학회논문집
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• 제2권2호
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• pp.115-126
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• 2000

Retaining walls are used to prevent excessive movement of retained soils. Typical retaining walls include gravity, reinforced concrete, reinforced earth and tie-back. However, from a practical viewpoint there are still drawbacks among these often constructed retaining walls. New types of retaining walls constructed with precast concrete blocks are proposed. This type of retaining wall is incorporates each blocks interconnected with adjacent block by connecting unit to build up a flexible retaining-wall system. This paper focus to behavior characteristics includes deformation and distribution of lateral earth pressure by loading tests and FEM analysis. For model tests, a 1/10 scale reduce models are manufactured include unevenness part, drainage hole and connecting unit and steel wire used to connect each blocks with adjacent block. To simulate the real retaining walls closely, uneven parts are interconnected each other and the construction type of blocks and wall front inclination are varied to investigate the relative displacement of individual block and the location of maximum deformation of wall as increasing surcharging. Additionally, PENTAGON3D, which solve the geotechnical and other problem, used for verifying and comparing with model tests.

• Nuclear Engineering and Technology
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• 제50권2호
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• pp.292-296
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• 2018

Recent events in the nuclear industry have resulted in a movement towards increased seismic and LOCA excitations and requirements that challenge current fuel designs. AREVA NP's GAIA fuel design introduces unique and robust characteristics to resist the effects of seismic and LOCA excitations. For demanding seismic and LOCA scenarios, fuel assembly spacer grids can undergo plastic deformations. These plastic deformations must not prohibit the complete insertion of the control rod assemblies and the cooling of the fuel rods after the accident. The specific structure of the GAIA spacer grid produces a unique and stable compressive deformation mode which maintains the regular array of the fuel rods and guide tubes. The stability of the spacer grid allows it to absorb a significant amount of energy without a loss of load-carrying capacity. The GAIA-specific grid behavior is in contrast to the typical spacer grid, which is characterized by a buckling instability. The increased mechanical robustness of the GAIA spacer grid is advantageous in meeting the increased seismic and LOCA loadings and the associated safety requirements. The unique GAIA spacer grid behavior will be incorporated into AREVA NP's licensed methodologies to take full benefit of the increased mechanical robustness.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2355-2364
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• 2018

We evaluated the effect of particle size and associated dynamics on a hydrocyclone separation process in order to understand the movement of the particle trajectories inside the hydrocyclone via numerical analysis, with particles of acid hydrolysis residues discharged in $TiO_2$ production via the sulfate method as a case study. The values obtained from the numerical simulation were successfully compared with those from experimental tests in the literature, allowing a description of the dynamics of the particles, their acting forces, and their relevant properties together with separation efficiency. The results showed that particle motion is jointly controlled by the drag force, the pressure gradient force and the centrifugal force. With increasing particle size, the influence of the drag force is weakened, whereas that of the centrifugal force and pressure gradient is strengthened. Factors including particle density, slurry viscosity, and inlet slurry flow rate also contribute to a clear and useful understanding of particle motion behavior in the hydrocyclone as a method for improving the separation efficiency.

• Smart Structures and Systems
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• 제24권2호
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• pp.223-231
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• 2019

The properties of Electroactive Polymer (EAP) materials are attracting the attention of engineers and scientists from many different disciplines. From the point-of-view of robotics, Ionic Polymer Metal Composites (IPMC) belong to the most developed group of the EAP class. To allow effective design of IPMC-actuated mechanisms with large induced strains, it is necessary to have adequate analytical tools for predicting the behavior of IPMC actuators as well as simulating their response as part of prototyping methodologies. This paper presents a novel IPMC motor construction. To simulate the bending behavior that is the dominant phenomenon of motor movement process, a nonlinear model is used. To accomplish the motor design, the IPMC model was identified via a series of experiments. In the proposed model, the curvature output and current transient fields accurately track the measured responses, which is verified by measurements. In this research, a three-dimensional Finite Element Method (FEM) model of the IPMC motor, composed of IPMC actuators, simultaneously determines the mechanical and electrical characteristics of the device and achieves reliable analysis results. The principle of the proposed drive and the output signals are illustrated in this paper. The proposed modelling approach can be used to design a variety of controllers and motors for effective micro-robotic applications, where soft and complex motion are required.

• 한국환경과학회지
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• 제29권8호
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• pp.809-818
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• 2020

To conserve the population of a hesperiid butterfly, Leptalina unicolor, inhabiting the protected areas of Jaeyaksan, we provide ecological information on their behavior and propose habitat conservation measures, such as the creation of alternative habitats based on comprehensive information. The behavioral study used a method of re-capture after releasing the butterfly with enamel marks on the wings. Adult behaviors were shown in four patterns: flying, settling on a plant, nectar absorption, and water absorption. Both males and females had the highest proportion of flight movement overall; however, males had a slightly higher proportion of flight movement. As for duration, females spent more time settling on plants to select spawning sites, and males seemed to take a longer time for water absorption activities, to absorb minerals needed to form the spermatophore. The average travel distance of butterflies was 27.5 m for females and 46.7 m for males, with daily activity ranges from 11.2 m to 43.8 m, and 21.4 to 57.6 m, respectively. The most important condition to preserve the habitat of Leptalina unicolor is to maintain the community of Miscanthus sinensis, a food plant. Additionally, because this butterfly has a high rate of water absorption activities, wetlands should be maintained.