• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.91-100
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• 2013

Current environment in civil and construction industry has changed to actively adopt construction management (CM) in various areas. While it is found that exemplary CM projects have been carried out in many civil engineering sectors, concrete system framework has not been suggested due to ambiguous boundary between CM and supervision system, unclear perception of CM's role, and inexperienced organization and regime. This paper investigated the challenges faced in civil and construction industry, and analyzed the strategy that could improve the current immature CM system by conducting questionnaire survey from experts in various construction sectors. The results could provide valuable information that can involve diverse opinions and view points in project participants.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.5
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• pp.31-35
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• 2011

In this paper, the miniaturized FM transmitter with dual-frequency is developed, and tested in the field. In this system two frequencies 88.1 MHz and 88.3 MHz is used. The transmitter is designed with 2.6 cm^3 system size, horizontal, vertical, height respectively. The operating voltage is 3.7 V and used the built-in storage battery in order to minimize. The system can use continuously during 7 hour with once charging. The channel separation ability is 40 dB. Consequently, this system is used conveniently with short distance information transmitter system at the industry field.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.1
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• pp.61-69
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• 2001

Polycarbonate(PC) membranes for oxygen enrichment from air were prepared by the wet phase inversion method. In order to improve oxygen separation performances of the PC membrane, the effect of the added ethanol(nonsolvent) and $CuCl_2$(metal salt) concentration in the casting solution on morphology, oxygen permeability ami $O_2/N_2$ separation factor of the membrane was studied. In addition, tensile strength and elongation at break of the membrane were investigated. An asymmetric membrane with a dense top layer and a porous sublayer was obtained. The thickness of the dense top layer decreased with increasing amount of nonsolvent additive. Compared with pure PC membrane without additive(metal salt), the oxygen permeability and $O_2/N_2$ separation factor of the $PC/CuCl_2$ membrane are significantly improved. The oxygen permeability and $O_2/N_2$ separation factor is $5.25{\times}10^{-9}cm^3(STP){\cdot}cm/cm^2{\cdot}sec{\cdot}cmHg$ and 4.5, respectively. This improvement might be due to good interaction between metal salt and oxygen.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.5
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• pp.25-30
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• 2017

In this Paper, we Propose the Low-cost Obstacle Recognition System Utilizing the Ultrasonic Sensor. Developed Obstacle Recognition System can be used to Aid the Visually Impaired Person. The Existence of the Obstacle is Notified to the Person through the Embodied Electronic Vibration Motor. The Timing Difference from the Recognition to the Notification Indicates the Distance to the Obstacle. Pulsed Ultrasonic Signal Controlled by MCU is Utilized and the Reflected Pulse through the Obstacle gives the Developed System the Existence of the Obstacle and the Distance to the Object. Pulse is sent Repetitively to Improve the Detection Accuracy. Developed Apparatus gives 30 Degree of Detection Angle and 2cm-30cm of the Detection Range when the Apparatus is Tested under Normal Walking Environment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.542-553
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• 2015

Objectives: Many types of dust collector are used for industrial ventilation, with the most common types being the cylinder bag filter system, rectangular bag filter system and cylinder type cartridge filter system. The cylinder type cartridge bag filter, which has more filtering area than other types of bag filter, can increase the pulse time and extend the useful life of the filter. This can save operational costs and installation area. Materials: This study used cylinder type cartridge bag filter equipment and tested the impact of vibration level and filter pressure with different pulse jet cleaning conditions. The final, cleaning efficiency was calculated through input dust mass and cleaning dust mass Conclusions: Two optimum cleaning condition groups were found. The first condition group was $3kgf/cm^2$ pulse pressure, 15 cm pulse distance, 0.2 s pulse time with an H-10 type nozzle. The second condition group was $3kgf/cm^2$ pulse pressure, 15 cm pulse distance, 0.3 s pulse time with an H-10 type nozzle.

• Fashion & Textile Research Journal
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• v.13 no.2
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• pp.147-154
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• 2011

The purpose of this study was to investigate the clothing image according to coloration, tone, and interval of checked pattern in color contrast. The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 24 color pictures, in which coloration(RB: Red+Blue, YP: Yellow+Purple), tone(light, dull, dark), and interval(0.5 cm, 1.5 cm, 3.5 cm, 5.5 cm) were manipulated. The 7-point scale was used for evaluation of clothing image. Data were obtained from 240 female college students living in Seoul, Gwangju, Jinju, and Masan on May 2010. For data analysis, ANOVA and Duncan-test were used by using SPSS program. Results of this study were as follows.; Clothing image according to coloration, tone, and interval of checked pattern consisted of five dimensions of attractiveness, freshness, appeal, modesty, and activity. Coloration showed an independent effect on attractiveness and appeal. Tone showed an independent effect on freshness, appeal, and modesty. Interval showed an independent effect on freshness. Also, interaction effects of coloration and tone on appeal were found. Interaction effects of coloration and interval on modesty were found.

• Journal of Industrial Technology
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• v.18
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• pp.363-370
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• 1998

This study focused on the development of an alternative stress estimation procedure to instantly calculate the critical stresses bonded concrete pavement. Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linearelastic material properties and static loading conditions. The well-known ILLI-SLAB finite element program was used for the analysis. Bonded concrete overlay analyzed the stress distribution, behavior and load carrying capacity under track load is made evaluation standard of bonded concrete overlay. In the study, the following results were derived ; The properties of strength is that compress and 3-point bending strength of existing pavement is deteriorated with $184kg/cm^2$, $59kg/cm^2$ but compress and splitting tensile strength of overlay is satisfied with $465kg/cm^2$, $45kg/cm^2$. Load transfers is happen at adjacent slab by interlocking under track load. The stress distribution under interior, corner and edge load is described high loading position surrounding then loading position.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.297-302
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• 2018

The wedge filter has two movements, fixed and dynamic. In this study, the depth dose distribution was analyzed to determine the stability of the dose distribution and dose volume histograms obtained by evaluating the usability of the critical normal tissue dose around the tumor dose. The depth dose was analyzed from the dose distribution from a Linac (6 MV and 10 MV irradiation field of energy $20{\times}20cm^2$, wedge filter with a SSD of 100 cm and $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ Y1-in (Left -7 cm), Y2-out(Right +7 cm). To analyze the fluctuations of the depth dose, a fixed wedge and dynamic wedge toe portion was examined according to the energy and angle because the size of the fluctuations was included in the error bound and did not show significant differences. The neck, breast, and pelvic dosimetry in tumor tissue are measured more commonly with a dynamic wedge than a fixed wedge presumably due to the error range. On the other hand, dosimetry of the surrounding normal tissue is more common using a fixed wedge than with a dynamic wedge.

• Journal of Korea Entertainment Industry Association
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• v.5 no.2
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• pp.166-172
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• 2011

This paper presents a sensor system which recognizes the location of a magnet using cheap hall sensor. The proposed methods measure magnetic field from a magnet using model equation, analyze the property of horizontal and vertical magnetic field, and decide the method of sensor arrangement. And, this paper proposes the algorithm which infers the location of a magnet from the measured magnetic field that relates the position between the magnet and the hall sensor, and calculate theoretical error, which is found to be no more than 0.0025cm. The results actually measured show that the measured error no more than 0.07cm and confirm that proposed systems are highly applicable to the various situations.

• Korean Journal of Ichthyology
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• v.35 no.3
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• pp.183-188
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• 2023

As a result of analyzing 469 Armoured cusk, Hoplobrotula armata, the range of total length was 10.5~63.5 cm and average total length was 30.3 cm. Using the IRI, shrimps were mainly prey component constituted 63.6%, followed by fishes, crabs, anomurans. The result of analysis in ontogenetic changes, shrimps were the most dominant prey in all size groups except for the ≥40.0 cm size group, and fishes were the most dominant prey in the size group of ≥40.0 cm. When the mean number of prey per stomach (mN/ST) and the mean weight of prey per stomach (mW/ST) were analyzed, mN/ST showed a significant difference (one-way ANOVA, P<0.05), but mW/ST did not (one-way ANOVA, P>0.05).