• Journal of Industrial Technology
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• v.37 no.1
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• pp.32-36
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• 2017

In this study, as part of a research on the development of economical high-performance concrete with high strength and high quality, the physical properties of high-performance concrete were analyzed by substituting a certain amount of low-cost domestic silica fume exempted from the re-importation type distribution structure of the domestic production and the existing high-priced silica fume distribution structure. Performing tests to identify the physical properties of the fresh and hardened concrete and durability analogy of the concrete which use low-cost domestic silica fume and imported silica fume, the chloride ion penetration resistance test result showed that the strength difference between the low-cost silica fume and the imported silica fume is not big but the strength of the low-cost silica fume was measured higher than the imported silica fume. The chloride ion penetration resistance of all variables was measured as "very low". Since the low-cost domestic silica fume can be used as a high-performance admixture of concrete, the results suggest that it is possible to produce a more economical high-performance concrete.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.113-120
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• 2007

Kimchi refrigerator is a specific refrigerator for Kimchi, Korean traditional fermented food. It has been fast popularized since it was developed about ten years ago. In this study, a survey was conducted with 103 female voluntary respondents to understand the customer satisfaction of the Kimchi refrigerator in the aspect of physical use. The respondents showed a high satisfaction for the use of refrigerators. It was, however, shown that they felt highly uncomfortable in using the refrigerator. In particular, the high discomfort was related to the fact that the customer should bend her torso very much to put Kimchi containers into the refrigerator, take them out of it, or clean its inside. Seventy-five percent of the respondents reported the experience of body-part pains and 58.4% of them reported pain experience in the back. It is presumed that these results are highly correlated to the top-cover design of the refrigerator, which is the most popular type to improve its performance of maintaining proper temperature. Therefore, the developers should consider these usability problems related to the refrigerator and try to enhance its usability by adopting ergonomics in the design stage.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.1
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• pp.9-17
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• 2011

Purpose : The purpose of this study was to compare the effects of performing feedback vs repeative tasks on lower extremity motor function and falls efficacy in chronic hemiplegic patients. Methods : 40 hemiplegic patients took part in this study. The average age of the feedback-task group was 68.45 years and 68.20 in the repeative-task group. All subjects participated in the study for 8 weeks, doing exercises 3 per day per week. All participants were assessed by using the Berg balance scale (BBS), the lower-extremity subscale of the Fugel-Meyer assessment of sensorimotor impairment (FMLE), and the falls efficacy scale (FES). The data were analyzed using a paired t-test. Results : After 8 weeks of exercise training, the results of this study were: the BBS and FMLE of hemiplegic patients showed a feedback-task and repeative-task groups (p<0.05). The FES of hemiplegic patients also showed a significant difference between the quantitative-task and qualitative-task groups (p<0.05). Conclusion : We present findings suggesting that chronic hemiplegic patients could improve their standing balance ability better through a feedback-task exercise program, as opposed to a repeative-task exercise program.

• Steel and Composite Structures
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• v.23 no.2
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• pp.153-160
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• 2017

It is extremely important to be aware of the ballistic performances of engineering materials in order to be able to choose the lightest armor providing full ballistic protection in civil and military applications. Therefore, ballistic tests are an important part of armor design process. In this study, ballistic performance of plates made of carbon steel and cold worked tool steel against 7.62 mm AP (armor-piercing) bullets was examined experimentally and numerically in accordance with NIJ standards. Samples in different sizes were prepared to demonstrate the effect of target thickness on ballistic performance. Some of these samples were coated with titanium nitride using physical vapor deposition (PVD) method. After examining all successful and unsuccessful samples at macro and micro levels, factors affecting ballistic performance were determined. Explicit non-linear analyses were made using Ls-Dyna software in order to confirm physical ballistic test results. It was observed that the ballistic features of steel plates used in simulations comply with actual physical test results.

• The Journal of Korean Physical Therapy
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• v.20 no.2
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• pp.19-24
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• 2008

Purpose: The purpose of this study was to examine how norepinephrine affects immunity in patients over age 65. Methods: We enrolled 25 male and female subjects age 65 or older. A low frequency electroacupuncture (EA) device was used to stimulate acupoint Hogu (L14). The 2 Hz frequency EA was applied to the acupoint for 20 minutes. Leukocyte subtypes-including neutrophils, lymphocytes, monocytes, eosinophils, and basophil-were then measured. The immunoglobulins IgG and IgM were also quantified. The data were finally analyzed using Wilcoxon singed-rank test and regression test as part of the SPSS WIN v. 10.1 program. Results: As norepinephrine levels decreased after EA stimulation, neutrophil, lymphocyte, and monocyte levels increased, and eosinophil and neutrophils levels decreased. Neutrophil and monocyte levels did not change to a statistically significant degree, but eosinophil levels showed a statistically significant decrease (p<0.05). Immunoglobulin IgG showed a statistically significant increase (p<0.05). Conclusion: This study showed that norepinephrine does affect immunity in persons over the age of 65. This indicates that there is an interaction between the nervous system and the immune system, and interaction that plays a crucial roles in the body's immune resistance and homeostasis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.43-51
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• 2015

This research was performed to investigate the quality of leaflets provided with newspapers. The leaflets were classified according to business types and regions. The physical and strength properties were analyzed. The sizes of leaflets were 2, 4, 8 jeoljis of crown octavo, A3, A4, A5, and B3, B4, B5. Most of them were color printed and both-sides printing was much more popular than one-side printing. The leaflets about electronics, educations, and clothing showed lower density than restaurant business and other areas. The leaflets of electronics, educations, and clothing, and large stores showed lower tensile strength, and those of restaurant businesses and building trades showed relatively high tensile strengths. No differences on the quality of leaflets except for large stores were found according to business areas. Large markets made the leaflets with various types of papers, and low quality papers were also included.

• The Journal of Korean Physical Therapy
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• v.16 no.3
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• pp.32-49
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• 2004

The primary purpose of this study was to provide the basic materials for C.V.A inpatients' actual use of medical service at the hospital with both the western and oriental medical department and the attitude on cooperative treatment. The results of this study were as follow: First, the subjects' general characteristics including job, monthly mean income and age made statistical differences to their pathological characteristics such as part of primary paralysis, detailed name of disease and cause of elicitation. Second, their general characteristics including religion and job produce statistical difference to their actual use of medical service, like medical institution form, term of treatment and type of medical institution at first-aid. Third, through the awareness of cooperative treatment system, the effect of C.V.A treatment and the shorten of the C.V.A treatment term were higher at oriental medical department inpatients and cooperative treatment serviced inpatients than western medical department inpatients and cooperative treatment non-serviced inpatients. Fourth, the biggest problem on current dual medical system is increase medical expenses and the biggest reason on not vitalized cooperative service is prejudice of both parts.

• Journal of Sensor Science and Technology
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• v.27 no.1
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• pp.59-63
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• 2018

Among Internet of things (IoT) applications, the most demanding requirements for the widespread realization of many IoT visions are security and low power. In terms of security, IoT applications include tasks that are rarely addressed before such as secure computation, trusted sensing, and communication, privacy, and so on. These tasks ask for new and better techniques for the protection of data, software, and hardware. An integral part of hardware cryptographic primitives are secret keys and unique IDs. Physical Unclonable Functions(PUF) are a unique class of circuits that leverage the inherent variations in manufacturing process to create unique, unclonable IDs and secret keys. In this paper, we propose a low power Arbiter PUF circuit with low error rate and high reliability compared with conventional arbiter PUFs. The proposed PUF utilizes a power gating structure to save the power consumption in sleep mode, and uses a razor flip-flop to increase reliability. PUF has been designed and implemented using a FPGA and a ASIC chip (a 0.35 um technology). Experimental results show that our proposed PUF solves the metastability problem and reduce the power consumption of PUF compared to the conventional Arbiter PUF. It is expected that the proposed PUF can be used in systems required low power consumption and high reliability such as low power encryption processors and low power biomedical systems.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.2
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• pp.26-33
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• 2007

This study was to investigate the reaction analysis of citizen on fence removal for securing green space. The results are as following; The majority of users went to green space more than one time per week to take a walk, rest and stayed there less than an hour. The places, where the fence removal was required mostly, were public institutions, parks and schools. The physical factor was the highest influence on whether the fence removal project could be expanded or not. With a slight difference from the physical factor, the environmental and emotional factor followed after. The social factor was also significant at 1 % level. In the physical aspect, the increase of garbage littering was the most negative part after fence removal.When the citizens were asked if they would participate in the fence removal project, the environmental and emotional factor and the social factor were the most influential ones on work places while the environmental and emotional factor influenced only on private houses.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.303-306
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• 2007

After Kyoto protocol took effect, many countries are making efforts to reduce $CO_2$ one of effective which is geosequestration. But a percentage of geosequestration in total research budget is very small and the priority order of research also is receded in Korea. As one of efforts to activate the research on geosequestration in field of geophysics, we proposed the plan to build up a measurement system for rock physical properties monitoring during $CO_2$ injection which will function as original technology. The system consists of two part, one of which is a data acquisition system based on seismic and complex resistivity tomographic measurement and the other of which is a tri-axial compressive system to realize the in-situ condition. And also developments of various inversion algorithms are proposed to interpret data qualitatively such as a inversion algorithm for confined cylindrical boundary, a joint inversion algorithm and a 4-D inversion algorithm.