• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.11-22
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• 2006

The muscular-skeletal disorders(MSDs) that have become a major issue recently in Korean industrial safety area are mainly caused by manual material handling task. The objective of this study is to provide scientific data for the establishment of work safety standard for Korean workers through the experiments of lifting task under various conditions, in order to prevent the muscular-skeletal disorders in the industrial work site. Eight male college students were recruited as participants. Three different lifting frequencies(1, 3, 5 lifts/min) and three twisting angles(including the sagittal plane and two asymmetric angles; i.e., 0°, 45°, 90°) for symmetric and asymmetric tasks, respectively, with three lifting range from floor to knuckle height, knuckle to shoulder, floor to shoulder height for one hour's work shift using free style lifting technique were studied. The maximum acceptable weight of load(MAWL) was determined under the different task conditions, and the oxygen consumption, heart rate, and RPE were measured or recorded while subjects were lifting their MAWLs. The results showed that: (1) The MAWLs were significantly decreased as the task frequency and task angle increased.; (2) The heart rate, oxygen consumption, RPE significantly increased with an increase in lifting frequency although maximum acceptable weight of lift decreased.; (3) The highest heart rate and oxygen consumption was recorded at the lifting range of floor to shoulder, followed by floor to knuckle and knuckle to shoulder.; (4) The RPE value showed that subjects perceived more exertion at the high frequency rate of lifting task and lifting range of floor to shoulder height. (5) The modeling for MAWL using isometric strength, task angle and lifting frequency were developed. It is expected that use of the results provided in this study may prove helpful in reducing MMH hazards, especially from lifting tasks for Korean, and can be used as a basis for pre-employment screening.

• Journal of the Korean Institute of Rural Architecture
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• v.4 no.3
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• pp.1-11
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• 2002

The aim of this research is to find-out the characteristics of Buddhist temples with relevant to Korean National cultural properties in Kum Kang(Kum-river) area. This analysis is accomplished by setting up the speciflc viewpoints where the charateristics can be perceived, and by measuring the form and angle from these points to the buddist culture ; 124 items were selected and analyzed by the comparative method. The most Important research finding is that both Traditonal Korean Temple and Kum Kang(Kum-river) Area site conceptualized and used a certain geometrical Feng-shui(geomancy) order in the disposition of mountain and river side according to the principles of human cognition. The conclusions are as follows ; Buddhist culture and the Characteristics of Buddhist temples in Kum Kang(Kum-river) Area having accumulated from the past and are the cultural complex and mixture of 7 elements. They also reflect cultural situations of each time period. The temples are a result of Korean traditional thought and spirit, as well as, regarding tradition as an important factor.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.255-266
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• 2017

In this study, self-supporting roofing elements especially convenient for large-span structures such as stadium, airport terminal, mall, coliseum, etc. were examined with respect to critical buckling load. These elements were assumed as laminated composite plates and, variation of free-edge forms, cutout types and lamination configurations were used as design parameters. Based on the architectural feature and structural requirements, the effects of curvilinear free-edge form on critical buckling load were focused on in this research. Within this scope, 14 types of lamination configuration were specified according to various orientation angle, number and thickness of plies with a constant value of total plate thickness. Besides that, 6 different types of cutout and 3 different free-edge forms were determined. By combining all these parameters 294 different critical buckling load analyses were performed by using ANSYS Mechanical software based on finite element method. Effects of those parameters on critical buckling load were evaluated referring to the obtained results. According to the results presented here, it may be concluded that lamination conditions have more significant influence on the critical buckling load values than the other parameters. On the other hand, it is perceived that curvilinear free-edge forms explicitly undergo changings depending on lamination conditions. For future work, existence of delamination might be considered and progression of the defect could be investigated by using non-linear analysis.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.412-417
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• 2000

TV ghost interference can be described as passive interference by the conducting part of transmission lines. In order to survey this interference from large-sized overhead EHV (extra high voltage) transmission line, TV reception quality was measured in the vicinity of that before and after construction. Instrumentation system was composed of ghost analyzer, TV received field intensity meter, VHF/UHF antennas, TV monitor and so on. The system is installed inside the vehicle. TV field intensity and PDUR (Perceived Desired wave to Undersired wave Ratio) are measured to evaluate TV ghost by using the system and vehicle. As the results, the useful data, which can be used to evaluate the effect of TV ghost interference from transmission lines could be obtained. In this paper, it is shown that the range of TV ghost interference from transmission lines can vary according to the frequency of TV electromagnetic wave, an incidence angle to the line and the other conditiions. At present, we are making efforts to establish a PDUR guideline for transmission lines.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.73-83
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• 2002

Gloss is very important optical property influencing the perceived quality of the paper surface as well as the surface after printing. Although the average gloss level of paper products or printed images is important to meet end use specifications, the occurrence of gloss mottle, or non-uniformity of gloss, is often of greater concern for meeting quality requirements, especially for the high gloss paper. Gloss variation originates from the irregularities of paper surface, especially surface roughness of paper. Roughness of paper can be divided into micro-roughness (under $1\mu m$ scale in variation) and macro-roughness (over $1\mu m$ scale in variation) depending on the scale of the irregularities. A clearer understanding of the gloss variation of paper can be achieved by separating the contributions of these two scales of roughness, and characterizing them independently. In order to do this, a novel gloss measuring method was introduced. This can detect local gloss with very high resolution. The effect of macro-roughness on gloss variation, which was identified by the measurable surface topography, was separated from the total gloss variation by using this method. The effect of micro-roughness was then estimated indirectly. The local gloss variations of various paper samples were then evaluated to demonstrate the utility of this approach.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.9-14
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• 2012

The objectives of this study were to compare the results of HSL (Health and Safety Laboratory) ramp test with perceived sense of slip onto the several different floor surfaces under contaminated conditions. There are a variety of approaches from biomechanical measurements to psychophysical test and human perception. However, controversies over these approaches still remain. Some widely accepted methods need to be improved. AHP (Analytic Hierarchy Process) was used to evaluate the perception of slipperiness of seven different floor surfaces under the contaminated condition with glycerol solution. Twelve subjects worn same footwear and walked with self-selected step and cadence along the test floors. The angle of inclination obtained for water wet condition using 5 l/min with HSL ramp test was compared to perception of slipperiness. The surface roughness ($R_z$) related very well both AHP (r=0.95) and ramp test (r=0.92). The high significant correlation (r=0.90) was found between AHP and HSL ramp test.The HSL ramp test values (Coefficient of Friction, COF) according to subjective evaluation were divided into two categories. There were high correlations between test results (subjective evaluation, HSL ramp test) and surface roughness in Rz. Perception rating obtained with AHP showed a high correlation with COF obtained with HSL ramp test.

• Journal of Korean Medical classics
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• v.20 no.3
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• pp.1-8
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• 2007

In "Hwangjenaegyeong", pathogenesis is explained based on theory of Yin and Yang. According to the theory, all environments surrounding us, physical and emotional both, are related to outbreak of diseases. This also reflects one of the major theories in oriental medicine, in which a human body is perceived as a correspondence to natural environment. In this theory, the main idea is to understand changes in the universe based on mutual correlations from within. This kind of perspective is easily criticized from scientific point of view. Whereas modern science pursue analytic thinking and objective information, the theories above seem rather vague. However, from a different angle, through a characteristic perspective of oriental medicine, actual significance can be found in the theory. Many diseases result from one's intemperate living habits. Therefore, much prevention can be made by self-control. Also, once disease occurs, the essential step to treatment is to find cause in the living environment and regain balance. Natural cure will take its' course when living habits recover moderate pace and are back in harmony with the environment.

• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.79-86
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• 2021

Objective: The purpose of this study was to identify the effect of reduced plantar cutaneous sensation on gait kinematics during walking with and without CAI. Method: A total of 20 subjects involved in this study and ten healthy subjects and 10 CAI subjects participated underwent ice-immersion of the plantar aspect of the feet before walking test in this study. The gait kinematics were measured before and after ice-immersion. Results: We observed a before ice-immersion on plantar cutaneous sensation, CAI subject were found to reduced ankle dorsiflexion, knee external rotation, hip adduction, and internal rotation compared to control subject. After ice-immersion, CAI subjects were found to reduce knee external rotation, hip adduction. However, no significant ankle joint kinematics. Conclusion: While walking, gait pattern differences were perceived between groups with and without plantar cutaneous sensation. The results of the study may explain the abductions in the hip angle movements in CAI patients at initial contact compared to healthy subjects in the control group when plantar cutaneous sensation was reduced. A change in proximal joint kinematics may be a conservative strategy to promote normal gait patterns in CAI patients.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.4 s.316
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• pp.60-69
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• 2007

The human eye usually experiences a loss of color sensitivity when it is subjected to high levels of luminance, and perceives a discrepancy in color between high and normal-luminance displays, generally known as a hue shift. Accordingly, this paper models the hue-shift phenomenon and proposes a hue-correction method to provide perceptual matching between high and normal-luminance displays. The value of hue-shift is determined by perceived hue matching experiments. At first the phenomenon is observed at three lightness levels, that is, the ratio of luminance is the same between high and normal-luminance display when the perceived hue matching experiments we performed. To quantify the hue-shift phenomenon for the whole hue angle, color patches with the same lightness are first created and equally spaced inside the hue angle. These patches are then displayed one-by-one on both displays with the ratio of luminance between two displays. Next, the hue value for each patch appearing on the high-luminance display is adjusted by observers until the perceived hue for the patches on both displays appears the same visually. After obtaining the hue-shift values, these values are fit piecewise to allow shifted-hue amounts to be approximately determined for arbitrary hue values of pixels in a high-luminance display and then used for correction. Essentially, input RGB values of an image is converted to CIELAB values, and then, LCh (lightness, chroma, and hue) values are calculated to obtain the hue values for all the pixels. These hue values are shifted according to the amount calculated by the functions of the hue-shift model. Finally, the corrected CIELAB values are calculated from corrected hue values, after that, output RGB values for all pixels are estimated. For evaluation, an observer's preference test was performed with hue-shift results and Almost observers conclude that the images from hue-shift model were visually matched with images on normal luminance display.

• Journal of Broadcast Engineering
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• v.18 no.1
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• pp.66-76
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• 2013

Although there has been much advance in the development of 3D displays of various purpose, 3D contents are not yet so used as expected in those displays. One well-known obstacle in the enjoyment of 3D contents is visual fatigue, but another major issue is image distortion of 3D contents. In the previous research, Shin, Li, & Kim (2012) reported systematic linear relationship between screen disparity and size perception of a simple object whose retinal size was constant across different disparities. In this research, we intended to generalize the previous finding by using various 3D stimuli in the test of the relationship between screen disparity and size perception of those stimuli. Consistent with previous findings, our data indicated that size perception linearly changes as a function of screen disparity and the linearity was observed in all stimuli types we used in this research. We described the empirical relationship between screen disparity and size perception in the form of prediction function for size perception in which visual angle is the predictor. This function will be very useful in the creation of 3D contents as one can make reasonable predictions on the to-be-perceived size of an object being filmed using screen disparity of their camera setting.