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A Case Study on the Human Error Analysis of Forklift Operations in a Small Enterprise (소규모 사업장의 지게차 작업에 관한 휴먼에러 분석 사례 연구)

  • Ha, Gyu Cheol;Park, Jungchul
    • Journal of the Korea Convergence Society
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    • v.12 no.5
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    • pp.207-215
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    • 2021
  • A forklift is an industrial vehicle with a power-operated fork for lifting and moving heavy loads over short distances. A significant number of accidents are caused by forklifts every year. Most of them are known to be caused by the unsafe acts of workers. However, only a few studies have focused on the risks of forklift work from the perspective of human error. In addition, various methods have been developed to analyze the risk of human error, while it is hard to find studies that directly compare the effectiveness or strengths/weaknesses of those methods. This study aims to analyze risk factors related to unsafe behavior in forklift operations using two representative human error analysis techniques, i.e., .SHERPA and HE-HAZOP, and compare their advantages and disadvantages. The analysis was performed on three main forklift operations ('unloading from the truck', 'moving and loading into the storage', and 'loading on the truck'). As a result, 118 errors and 34 remedial measures were derived by SHERPA. Through HAZOP, 139 errors and 54 measures were derived. The two techniques were compared in terms of the number of results and the method of deriving errors and remedial measures, cause analysis, and risk assessment. This study might be used to reduce human error related disasters in workplaces using forklifts. In order to provide a guide for choosing an appropriate analysis method, more comparative studies on different techniques involving wide range of tasks are needed in the future.

Characterization of Materials and Color Formation for Black Potteries from the Proto-Three Kingdoms Period in Ulsan, Korea (울산지역 원삼국시대 흑색토기의 재질 및 발색 특성)

  • Kim, Su Kyoung;Jang, Sungyoon;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.37 no.2
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    • pp.77-89
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    • 2021
  • In this study, materials and color formation techniques were assessed for black potteries excavated from the Janghyeon-dong, Jungsan-dong and Gyodong-ri sites during the Proto-Three Kingdoms period in Ulsan, Korea. Although the black potteries were black superficially, the inner cores were either black or reddish yellow. Microscopy analysis identified that body clay was used for reddish iron oxide rich soils with quartz, alkali feldspar and mica, along with grains of myrmechite texture. Additionally, as marginal differences exist in the contents of SiO2, Fe2O3 and CaO, the composition of the host rock and clay distributed around the sites was affected. Thus, we can deduce that pottery was made by soiling at a short distance. Raman spectroscopy results revealed that the black layer of the black pottery was used as amorphous combustion carbon. In addition, as a transparent layer of brown lacquer was observed on the substrate that was in contact with the surface layer, the black layer of the pottery induced black color development by a combination of combustion carbon and lacquer. Based on the mineral composition and microtexture of the body clay, the firing temperature of the potteries seemed to range from 750 to 850℃, whereas the lacquer layer was pyrolyzed at 468℃ by thermal analysis. Therefore, a combined layer of combustion carbon and lacquer, which formed the black color, was painted after the body clay was fired.

Effect of Wrist Stabilization Exercise Combined with Taping on Wrist Health and Quality of Life in Postpartum Women with Wrist Pain (테이핑과 손목 안정화 운동의 병행훈련이 출산 후 여성의 손목건강과 삶의 질에 미치는 효과)

  • Jung, Kyoung-Sim;In, Tae-Sung
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.4
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    • pp.393-400
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    • 2020
  • The purpose of this study was to determine whether wrist stabilization exercise combined with taping would improve wrist pain, disability and quality of life in postpartum women with wrist pain. Seventeen wrist pain patients were recruited and were randomly divided into two groups: experimental group (n=8) and control group (n=9). Participants in both groups received taping therapy for 30 minutes before the intervention. Additionally, subject in the experimental group performed wrist stabilization exercise using theraband for 15 minutes (twice a day, five times a week for four weeks) while the control group conducted range of motion exercise for the same amount of time. VAS was used to assess pain level of wrist. Disability was measured using a DASH. Quality of life were measured by SF-36. The wrist pain in the experimental group improved significantly greater than the control group (p<0.05). Significant improvement in the disability was observed in the experimental group compared to the control group (p<0.05). The SF 36 in the experimental group improved significantly greater than the control group (p<0.05). Our findings indicate that wrist stabilization exercise combined with taping is beneficial and effective to improve wrist health and quality of life in postpartum women with wrist pain.

Implementation of Real-time Sedentary Posture Correction Cushion Using Capacitive Pressure Sensor Based on Conductive Textile

  • Kim, HoonKi;Park, HyungSoo;Oh, JiWon
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.2
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    • pp.153-161
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    • 2022
  • Physical activities are decreasing and sitting time is increasing due to the automation, smartization, and intelligence of necessary household items throughout daily life. Recent healthcare studies have reported that the likelihood of obesity, diabetes, cardiovascular disease, and early death increases in proportion to sitting time. In this paper, we develop a sitting posture correction cushion in real time using capacitive pressure sensor based on conductive textile. It develops a pressure sensor using conductive textile, a key component of the posture correction cushion, and develops a low power-based pressure measurement circuit. It provides a function to transmit sensor values measured in real time to smartphones using BLE short-range wireless communication on the posture correction cushion, and develops a mobile application to check the condition of the sitting posture through these sensor values. In the mobile app, you can visualize your sitting posture and check it in real time, and if you keep it in the wrong posture for a certain period of time, you can notify it through an alarm. In addition, it is possible to visualize the sitting time and posture accuracy in a graph. Through the correction cushion in this paper, we experiment with how effective it is to correct the user's posture by recognizing the user's sitting posture, and present differentiation and excellence compared to other product.

A Study on the Adequate HD Camera Focal Length in the Broadcasting Studio using LED Video Wall (LED 비디오월을 사용하는 방송환경에서 HD 카메라의 적정 초점거리 연구)

  • Choi, Ki-chang;Kwon, Soon-chul;Lee, Seung-hyun
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.713-721
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    • 2022
  • In order to use the LED video wall in the broadcasting studio, there are a few things to be aware of. First, since the pixels are closely arranged, a moire phenomenon may occur due to a short arrangement period, and second, the distance between pixels (pixel pitch) may be recorded on the image sensor of the broadcasting camera. When moire occurs or pixel pitch is observed, viewers feel uncomfortable. Moire effect can be reduced by adjusting the shooting distance or angle of the camera, but in order to prevent the pixel pitch from being recorded on the image sensor, secure a sufficient distance between the LED video wall and camera. even when the distance secured, the zoom lens used in the broadcasting studio must be operated by appropriately changing the magnification. If the focal length is changed by changing the magnification to obtain a desired angle of view, the pixel pitch may be unintentionally recorded. In this study we propose the range that the pixel pitch is not observed while changing the magnification ratio of the zoom lens when the distance from the video wall is sufficiently secured. The content was played back on the LED video wall and the LED video wall was recorded on the server using an HD camera equipped with a B4 mount zoom lens

Segregation Mode of Plant Height in Crosses of Rice Cultivars Ⅸ. Crosses between Semi-dwarf Japonicas and Semi-dwarf(d-t) gene Testers (수도 품종간 교잡에 있어서 간장의 유전분리 Ⅸ. 단간 Japonica 품종과 Semi-dwarf (d-t) gene 검정친과의 조합)

  • Kim, Yong-Kwon;Kim, Hong-Yeol;Nam, Yeong-Woo;Park, Sun-Zik;Heu, Mun-Hue
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.30 no.4
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    • pp.449-454
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    • 1985
  • In order to search for the semi-dwarf japonica varieties allelic to the semi-dwarf rice cultivar which is controlled by d-t gene, seven dwarf japonica varieties. Reimei, Hoyoku. Shiranui, Kokumasari, M 7. S.224 and S.295 were crossed to the semi-dwarf cultivar, wx 817. wx 817 is known to have semi-dwarf gene d-t. Their F$_1$, F$_2$ and F$_3$ were grown in 1984 and 1985 and culm lengths were measured at harvest. The results are summarized as follows. 1. The F$_2$s of all 7 cross combinations showed normal distribution and no segregation. 2. The range of culm length variation in the F$_3$ was variable depending on the cross combination, but the general pattern was similar in the all 7 crosses. 3. The mean of F$_3$ and parental F$_2$ mean which were selected into short, medium and tall groups were similar and showed no segregation, implying the selection efficiency in F$_2$. 4. From the results of F$_2$ and F$_3$ segregations, it is concluded that the culm length of the 7 semi-dwarf japonicas tested here are controlled by the same major gene d-t although they are modified by different minor genes.

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BEEF MEAT TRACEABILITY. CAN NIRS COULD HELP\ulcorner

  • Cozzolino, D.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1246-1246
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    • 2001
  • The quality of meat is highly variable in many properties. This variability originates from both animal production and meat processing. At the pre-slaughter stage, animal factors such as breed, sex, age contribute to this variability. Environmental factors include feeding, rearing, transport and conditions just before slaughter (Hildrum et al., 1995). Meat can be presented in a variety of forms, each offering different opportunities for adulteration and contamination. This has imposed great pressure on the food manufacturing industry to guarantee the safety of meat. Tissue and muscle speciation of flesh foods, as well as speciation of animal derived by-products fed to all classes of domestic animals, are now perhaps the most important uncertainty which the food industry must resolve to allay consumer concern. Recently, there is a demand for rapid and low cost methods of direct quality measurements in both food and food ingredients (including high performance liquid chromatography (HPLC), thin layer chromatography (TLC), enzymatic and inmunological tests (e.g. ELISA test) and physical tests) to establish their authenticity and hence guarantee the quality of products manufactured for consumers (Holland et al., 1998). The use of Near Infrared Reflectance Spectroscopy (NIRS) for the rapid, precise and non-destructive analysis of a wide range of organic materials has been comprehensively documented (Osborne et at., 1993). Most of the established methods have involved the development of NIRS calibrations for the quantitative prediction of composition in meat (Ben-Gera and Norris, 1968; Lanza, 1983; Clark and Short, 1994). This was a rational strategy to pursue during the initial stages of its application, given the type of equipment available, the state of development of the emerging discipline of chemometrics and the overwhelming commercial interest in solving such problems (Downey, 1994). One of the advantages of NIRS technology is not only to assess chemical structures through the analysis of the molecular bonds in the near infrared spectrum, but also to build an optical model characteristic of the sample which behaves like the “finger print” of the sample. This opens the possibility of using spectra to determine complex attributes of organic structures, which are related to molecular chromophores, organoleptic scores and sensory characteristics (Hildrum et al., 1994, 1995; Park et al., 1998). In addition, the application of statistical packages like principal component or discriminant analysis provides the possibility to understand the optical properties of the sample and make a classification without the chemical information. The objectives of this present work were: (1) to examine two methods of sample presentation to the instrument (intact and minced) and (2) to explore the use of principal component analysis (PCA) and Soft Independent Modelling of class Analogy (SIMCA) to classify muscles by quality attributes. Seventy-eight (n: 78) beef muscles (m. longissimus dorsi) from Hereford breed of cattle were used. The samples were scanned in a NIRS monochromator instrument (NIR Systems 6500, Silver Spring, MD, USA) in reflectance mode (log 1/R). Both intact and minced presentation to the instrument were explored. Qualitative analysis of optical information through PCA and SIMCA analysis showed differences in muscles resulting from two different feeding systems.

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Impact of Urban Thermal Environment Improvement by Street Trees and Pavement Surface Albedo (가로수와 바닥 포장 표면 알베도의 도시 열 환경 개선 효과)

  • Na-youn Kim;Eun-sub Kim;Seok-hwan Yun;Zheng-gang Piao;Sang-hyuck Kim;Sang-jun Nam;Hwa-Jun Jea;Dong-kun Lee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.1
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    • pp.47-59
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    • 2023
  • Due to climate change and urbanization, abnormally high temperatures and heat waves are expected to increase in urban and deteriorate thermal comfort. Planting of street trees and changing the albedo of urban surfaces are the strategies for mitigating the thermal environment of urban, and both of these strategies affect the exposure and blocking of radiative fluxes to pedestrians. After measuring the shortwave and longwave radiation according to the ground surface with different albedo and the presence of street trees using the CNR4 net radiometer, this study analyzed the relationship between this two strategies in terms of thermal environment mitigation by calculating the MRT(Mean Radiant Temperature) of each environment. As a result of comparing the difference between the downward shortwave radiation measured under the right tree and at the control, the shortwave radiation blocking effect of the tree increased as the downward shortwave radiation increased. During daytime hours (from 11 am to 3 pm), the MRT difference caused by the albedo difference(The albedo of the surfaces are 0.479 and 0.131, respectively.) on surfaces with no tree is approximately 3.58℃. When tree is present, the MRT difference caused by the albedo difference is approximately 0.49℃. In addition, in the case of the light-colored ground surface with high albedo, the surface temperature was low and the range of temperature change was lower than the surrounding surface with low albedo. This result shows that the urban thermal environment can be midigate through the planting of street trees, and that the ground surface with high albedo can be considered for short pedestrians. These results can be utilized in planning street and open space in urban by choosing surfaces with high albedo along with the shading effect of vegetation, considering the use by various users.

Applicability Analysis of the FE Analysis Method Based on the Empirical Equation for Near-field Explosions (근거리 폭발에 대한 경험식 기반 유한요소해석 방법의 적용성 분석)

  • Hyun-Seop, Shin;Sung-Wook, Kim;Jae-Heum, Moon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.6
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    • pp.333-342
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    • 2022
  • The blast analysis method entails the use of an empirical equation and application of the pressure-time history curve as an explosive load. Although this method is efficient owing to its simple model and short run time, previous studies indicate that it may not be appropriate for near-field explosions. In this study, we investigated why different results were observed for the analysis method by considering an RC beam under near-field explosion conditions with the scaled distance of 0.4-1.0 as an example. On this basis, we examined the application range of the empirical analysis method by using the finite element analysis program LS-DYNA. The results indicate that the empirical analysis method based on data from far-field explosion tests underestimates the impulse. Thus, the calculated deflection of the RC beam would be smaller than the measured deflection and arbitrary Lagrangian-Eulerian (ALE) analysis result. The ALE analysis method is more suitable for near-field explosion conditions wherein the structural responses are large.

Development of Simulator for Analyzing Intercept Performance of Surface-to-air Missile (지대공미사일 요격 성능 분석 시뮬레이터 개발)

  • Kim, Ki-Hwan;Seo, Yoon-Ho
    • Journal of the Korea Society for Simulation
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    • v.19 no.1
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    • pp.63-71
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    • 2010
  • In modern war, Intercept Performance of SAM(Surface to Air Missile) is gaining importance as range and precision of Missile and Guided Weapon on information warfare have been improved. An aerial defence system using Surface-to-air Radar and Guided Missile is needed to be built for prediction and defense from threatening aerial attack. When developing SAM, M&S is used to free from a time limit and a space restriction. M&S is widely applied to education, training, and design of newest Weapon System. This study was conducted to develop simulator for evaluation of Intercept Performance of SAM. In this study, architecture of Intercept Performance of SAM analysis simulator for estimation of Intercept Performance of various SAM was suggested and developed. The developed Intercept Performance of SAM analysis simulator was developed by C++ and Direct3D, and through 3D visualization using the Direct3D, it shows procedures of the simulation on a user animation window. Information about design and operation of Fighting model is entered through input window of the simulator, and simulation engine consisted of Object Manager, Operation Manager, and Integrated Manager conducts modeling and simulation automatically using the information, so the simulator gives user feedback in a short time.