• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.1
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• pp.63-76
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• 2015

This study conducted a survey to gauge the buying and wearing propensities of wearers of leg guards made for baseball catchers, as well as product characteristics of preferred leg guards. Data from the survey were analyzed to obtain basic data for the development of an advanced leg guard design. Degree of compression, horizontal distance, cross section view and outline 3D sketch were also analyzed from the 3D data of leg guards; in addition, mobility and kinematic analysis were conducted through a wearing test. The survey indicated that imported products dominate the current retail market because they are appreciated by customers in terms of fit, price, brand, and protection. Representative complaints of products were discomfort, pressure, and the heavy-weight of the leg guards in general attributed to overall structure and 3D shape. When the pressure was lower on the front area of knee, it feels better to wear and the average knee angular velocity during the up and down motion increased, which suggests a better design from a kinematic point of view. The knee is the primary part of the body responsible for any movement of the lower limbs; consequently, the degree of compression and support stability of the leg guards near the knee area are important factors to evaluate the performance of leg guards. The results of our study indicate significant opportunities for improvement in product design and the development of baseball leg guards along with an ergonomic design that considers the mobility of the knee, skin deformations is necessary to improve performance. The process followed in this study will be applicable to studies on other personal protective equipment for sports.

• Korean Journal of Applied Biomechanics
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• v.27 no.4
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• pp.239-245
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• 2017

Objective: The bobsleigh shoes used in the start section are one of the most important equipment for improving the competition. Despite the importance of the start section, there are no shoes that are specific for bobsleigh athletes in Korea and Korean athletes have to wear sprint spike shoes and practice the start instead of wearing bobsleigh shoes. The objective of the present study was to provide data for improving the performance of Korean bobsleigh athletes by investigating the differences in their split time, plantar pressure, and forefoot bending angle based on skill levels at the start of a run under the same conditions as training conditions. Method: Six Korean bobsleigh athletes were divided into two groups, superior (n=3) and non-superior (n=3). A digital speedometer measured the split time at the start; the Pedar-X system (Novel, Germany) measured plantar pressure. Plantar pressures and split times were measured as the athletes pushed a bobsleigh and sprinted at full speed from the start line to the 10-m mark on the bobsleigh track. An ultra-high-speed camera was used to measure the forefoot bending angle during the start phase. Results: Significant between-group differences were found in split times (p<.000; superior = 2.38 s, non-superior = 2.52 s). The superior group had a larger rearfoot (p<.05) contact area, maximum rearfoot force (p<.01), and a larger change in angles 3 and 4 (p<.05). Conclusion: At the start of a bobsleigh run, proper use of the rearfoot for achieving effective driving force and increasing frictional resistance through a wider frictional force can shorten start time.

• Journal of radiological science and technology
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• v.14 no.2
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• pp.15-21
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• 1991

Experiment was conducted on the image quality and exposure dose following replacement of $CaWO_4$ system screen BH-III and BX-III which have so far been used for high-voltage hard-radiation quality radiography, with rare earth system screen KO750, combined with high contrast film SRH, while additional filter was altered, Cu 0.8 mm+Al 1.4 mm(HVL : Al 8.8 mm), Cu 1.3 mm+Al 1.0 mm(HVL : Al 10.6 mm) and Cu 1.8 mm+Al 1.5 mm(HVL : Al 11.4 mm). AS a result, visual evaluation did not detect extreme changes in image quality under the respective condition(HVL : $Al\;8.8\;mm{\sim}Al\;11.4\;mm$). It was noted, however, that surface exposure dose declined with an increase in the thickness of the additional filter, as it was $18.9\;{\mu}Gy$ at HVL Al 8.8 mm, $17.5\;{\mu}Gy$ at Al 10.6 mm and $15.7\;{\mu}Gy$ at Al 11.4 mm. Considering the limited rating of X-ray equipment and wear of machinery, however, the range of $Cu\;1.3\;mm{\sim}1.8\;mm+Al\;1.0\;mm{\sim}1.5\;mm(1/16\;VL{\sim}1/32\;VL)$ seemed to be a limit.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.473-476
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• 2012

The PET-MRI which has been installed and being managed recently uses both magnetic field and radiation. Most radiation workers wear a thermoluminescenct dosimeter (TLD) as a personal radiation dosimeter, and the TLD is affected both by a magnetic field and radiation. In this research, the same amount of X-ray was applied to 36 TLDs, and the changes in the dose of the 32 TLDs exposed to magnetic field at the location where its intensity of the magnetic resonance imaging (MRI) was about 5000 Gauss for eight hours with one-hour unit and that of the four TLDs not exposed to magnetic field were compared and checked. The measurement result showed that exposure dose of the TLD attached to the MRI changed irregularly depending on the amount of exposure time. Therefore, the TLD whose amount of changes little in the environment of a MRI is demanded to be developed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.4
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• pp.389-395
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• 2016

Objectives: Acute methanol poisonings known to be typical occupational diseases occurring in developing countries broke out in sub-contract manufacturers in the early 2016. The present paper attempted to identify underlying causes which hide under apparent findings, and suggest alternative policies to prevent recurrence of similar intoxication Methods: We evaluated occupational health and safety characteristics of workers in micro-enterprises similar to workplaces with methanol poisoning by in depth-interview of employers, workers, and labor inspectors, and literature review. Results: The common findings of workplaces with methanol poisoning were addressed; First, the victims were illegal agency workers. Second, the workplaces were sub-contract micro-manufacturers with less than 5 employees. Investigators found that local ventilations did not work, while most of workers did not wear any proper personal respiratory protective equipment in the workplace. In addition, periodic environmental monitoring and medical check-ups were not done. However, these apparent findings do not appear to be root causes of methanol poisoning. Our in depth-analysis clarified a root cause; micro-enterprises with less than 5 employees are exempted with essential regulations of OSH Act, and employers do not know about OSH Act. Conclusions: We suggest occupational health policies to prevent recurrence of similar intoxication; First, government should introduce programs so that all employers should know about employers' responsibilities in OSH Act from the start of business. Second, even manufacturers with less than 5 employees should not be exempted with essential regulations of OSH Act. Finally, employers should take responsibilities for health and safety of all the workers including agency workers working in workplaces.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.860-865
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• 2009

This thesis deals with application of Windows CE for Embedded System and the development methode of "Speed Gate Controller Tester" taking advantage of development program. We can improve reliability, stability and convenience of maintenance work as use of "Speed Gate Controller Tester" which was developed and applied "Embedded System" We can provide customers with more qualified service naturally because of the higher rate of operation which makes people use more pleasant and comfortable subway facility. And also it is possible to manage processor, time schedule and hardware resource as application of Embedded System and Windows CE. Embedded System applied OS Windows CE makes it possible to develop other various products, another application of equipment and tester. Thus this paper treats problems the moment developed and the present condition, development process, field application results.

• Journal of Drive and Control
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• v.12 no.1
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• pp.1-8
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• 2015

The stability of friction characteristics and thermal management for a dry type dual clutch transmission (DCT) are inferior to those of a wet clutch. Too high temperature resulting from frequent engagement of DCT speeds up degradation or serious wear of the pressure plate or burning of the clutch disk lining. Even though it is significantly important to estimate the temperature of a dry double clutch (DDC) in real-time, few meaningful study of the thermal model of DDC has been known yet. This study presented a thermal analytical model of lumped parameters for a DDC by analyzing its each component firstly. Then a series of experimental test was carried out on the test bench with a patented temperature telemetry system to validate the proposed thermal model. The thermal model, whose optimal parameter values were found by optimization algorithm, was also simulated on the experimental test conditions. The simulation results of DDC temperature show consistency with the experiment, which validates the proposed thermal model of DDC.

• Fashion & Textile Research Journal
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• v.22 no.4
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• pp.407-412
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• 2020

This study investigated the technological development of Korean functional product design for posture correction. We analyzed registered and disclosed Korean patents (n=289) of KIPRIS. They were posture correction technology patents filed from 1999 to 2018. Keywords used in patent selection were posture correction, posture correction clothing, posture correction band, rehabilitation clothing, joint protection, protective equipment, and compression wear. These were then analyzed by patent application year, product type, effect pursued, and posture correction body part. The results showed that patent applications related to posture correction technology have increased since 2014. Products subject to patents for posture correction technology were device/brace (59.5%), footwear (22.5%), and clothing (18.0%). Patents for posture correction pursued various wearing effects. The effects pursued were dependent on the product type. The device/brace focused on joint protection (76.7%) and muscle reinforcement (40.7%). Footwear was focused on joint protection (90.8%). The clothes were focused on muscle reinforcement (50.0%) and body shaping (36.5%). The clothing and device/brace for posture correction were worn on various body parts of the upper limbs to feet. The posture correction product design patent was to correct various body parts. Patents pursuing upper body correction focused on spine posture correction (n=99). Patents for foot posture correction have steadily increased (n=102). Patents for posture correction of the pelvis and hip joints were relatively few (n=46). The results of this study implied the necessity to develop technology to correct posture by combining the functions of device/brace and clothing.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.57-65
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• 1996

The latest date, No. 1 YouII was grounded and sunk into the sea at MAMHYUNGJEDO ( South brother Island) in Sep. 21. 1995, and M.V. Sea Prince of V.L.C.C also made a big oil poullution accident owing to Typhoon "Paei" at front sea of Yeu Choun on Jul. 25. 1995. The large or small scall scale of oil poullution accident frequently was occurred about 300-350 cases per ine(1) year. The countries advanced in marine relations like as, nited Kingdom and Japan, have perfect system The country of expert education, training and oil recovery equipments in oil poullution accidents. The large quantity oil skimming ship's basic condition need general skimming ship which was high speed and large quantity skimming ability , and hve to store the recovered oil into tanks This oil skimming shop are composit the skimmer whuch move up and down according to the wace movements, storage tank which storage the recovered oil in after side, transfer pump which transformed from flooding tank to separating tank and separating tank which separated the oil mixtures, Also there are cylindrical floated which keep the auto positing, gate which keep the auto positing, gate which protect and guide the recovering oil from sea and balance weight for skimmer balance. Also there are cylindrical floated which keep the auto positing, gate which protect and guide the recovering oil from sea and balance weight for skimmer balance. The important arrangement is twin arm which moved by two hinge and move te skimming unit by wave movement. In gate of inside, made long wear in the gate bellow position, there are also connected the flexible hose for oil mixtures drop. The separating tank composited with multi-divided bulkhead for ffective oil and sea water separating by settling and flotation principle. As use the above natural princile and equipment, we can remove the large quantity oil by developed oil skimming ship.ming ship.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.1
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• pp.1-8
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• 2018

As the key equipment in deep ocean mining, the slurry pump suffers from wear and blocking problems. In this paper, high-speed photography technique is applied to track the movement rule of single particle of the coarse particle solid-liquid two-phase flow in a double blade slurry pump. The influences of particle diameter and particle density on the pass-through and collision characteristics of particles are analyzed as well. The results show that the average of the passing pump time first decreases and then increases when the particle diameter increases. The average of the passing pump time decreases by 22.7%, when the particle density increases from $1.09g/cm^3$ to $1.75g/cm^3$. Besides, the particle density has great influence on the location where the particle hits the tongue. Most particles of $1.09g/cm^3$ hit the tongue on the left side, while collision location of particles of $1.75g/cm^3$ is mainly on the top and at the right side of the tongue. The research can provide a basis for the optimization design of slurry pump in deep ocean mining system.