• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.80-85
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• 2012

Purpose: The whole body bone scan is an examination that visualizing physiological change of bones and using bone-congenial radiopharmaceutical. The patients are intravenous injected radiopharmaceutical which labeled with radioactive isotope ($^{99m}Tc$) emitting 140 keV gammarays and scanned after injection. The 3 principles of radiation protection from external exposureare time, distance and shielding. On the 3 principles of radiation protection basis, radiopharmaceutical might just as well be injected rapidly for reducing radiation because it might be the unopened radiation source. However the radiopharmaceuticals are injected into patient directly and there is a limitation of distance control. This study confirmed the change of radiation exposure as change of distance from radiopharmaceutical and observed the change of radiation exposure afte rsetting a shelter for help to control radio-technician's exposure. Materials & methods: For calculate the average of injection time, the trained injector measured the injection time for 50 times and calculated the average (2 minutes). We made a source as filled the 99mTc-HDP 925 MBq 0.2 mL in a 1 mL syringe and measured the radiation exposure from 50 cm,100 cm,150 cm and 200 cm by using Geiger-Mueller counter (FH-40, Thermo Scientific, USA). Then we settled a lead shielding (lead equivalent 6 mm) from the source 25 cm distance and measured the radiation exposure from 50 cm distance. For verify the reproducibility, the measurement was done among 20 times. The correlation between before and after shielding was verified by using SPSS (ver. 18) as paired t-test. Results: The radiation doses according to distance during 2 minutes from the source without shielding were $1.986{\pm}0.052{\mu}$ Sv in 50 cm, $0.515{\pm}0.022{\mu}$ Sv in 100 cm, $0.251{\pm}0.012{\mu}$ Sv in 150 cm, $0.148{\pm}0.006{\mu}$ Sv in 200 cm. After setting the shielding, the radiation dose was $0.035{\pm}0.003{\mu}$ Sv. Therefore, there was a statistical significant difference between the radiation doses with shielding and without shielding ($p$<0.001). Conclusion: Because the great importance of whole body bone scan in the nuclear medicine, we should make an effort to reduce radiation exposure during radiopharmaceutical injections by referring the principles of radiation protection from external exposure. However there is a limitation of distance for direct injection and time for patients having attenuated tubules. We confirmed the reduction of radiation exposure by increasing distance. In case of setting shield from source 25 cm away, we confirmed reducing of radiation exposure. Therefore it would be better for reducing of radiation exposure to using shield during radiopharmaceutical injection.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.51-60
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• 2012

In order to characterize the shear strength of the frozen sand for foundation design in cold region and prediction of adfreeze bond strength, many researchers developed test techniques and carried out many tests to analyze shear strength properties of the frozen sand for half a century. However, many studies for shear strength properties of the frozen sand have been carried out with limited circumstances, even though shear strength of the froze sand can be affected by various influence factors such as soil type, temperature conditions, and magnitude of normal stress. In this study, direct shear test equipment was used to analyze the shear strength characteristics of the frozen sand. Direct shear test equipment was designed for cold weather, and the direct shear tests were carried out inside of large-scaled low temperature chamber. Three soil types-two uniform sands and one well graded soil were used to analyze the shear strength of the frozen sand with three different temperature conditions and three different vertical confining pressures. In this research, a series of direct shear tests for shear strength of the frozen sand have been conducted to demonstrate the efficiency of effectiveness of the test equipment and low temperature chamber. This research also showed that shear strength of the froze sand increased with decreasing temperature condition, but the influence of vertical confining pressure was insignificant to the shear strength of the frozen sand.

• Journal of the Korea Concrete Institute
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• v.13 no.6
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• pp.619-628
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• 2001

In building construction, openings of the story-height deep beams are usually required for accessibility and service lines such as air conditioning ducts, drain pipes and electric units. It is known that the main parameters affecting the load bearing capacity of deep beams with web openings are size, shape, location and reinforcements of openings. However, there have been no pertinent theories and national design codes for predicting ultimate shear strength of reinforced concrete deep beams with web openings. In this study, the shear behavior of simply supported reinforced concrete deep beams with web openings subject to concentrated loads has been scrutinized experimentally. A total of 34 specimens, the geometry of openings, its reinforcements and shear span to depth ratio, being taken as the experimental variables, has been cast and tested in the laboratory. The effects of these structural parameters on the shear strength and crack initiation and propagation have been carefully checked and analyzed. From the tests, it has been observed that the failures of all specimens were due to shear mechanism and the ultimate strength of specimens varies according to the location of openings, by which the formation of compression struts between the loading points and supports are deterred. All of the test results of specimens have been compared with the formulas proposed by previous researchers. The results were closely coincident with the formulas given by Ray and Kong's equation except for some X series specimens having a larger dimension of openings beyond the geometric limits of proposed equations.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.39-51
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• 2017

Recently, looking at construction sites with either large or small scale, accidents like collision, fall, etc. occur often. These accidents lead to not only damage of human lives but also serious economic loss. In case of large scale constructions sites, safety management systems are used to reduce industrial accidents. However in construction sites with small scale, those systems cannot be applied due to problems such as lack of compatability and high installation expense. In this case, just by putting on safety gears can also reduce industrial accidents. Therefore, in this paper, a safety management systems that can be used at both large and small scale construction sites is proposed. This safety management system consists of a smart module, a repeater and a gateway, and a monitoring system. The smart module, which is detachable, is attached to a safety helmet. This module transfers the current status of the user to the monitoring system through the repeater and the gateway. The repeater transfers the data received from the smart module to the gateway, and the gateway sends the data from the repeater to the monitoring system. The monitoring system shows the user status to the safety supervisor by displaying the data - temperature, height, intensity of illumination, images - received from the smart module. The safety supervisor can monitor the user status in real-time and take immediate action in case of emergency through this monitoring system.

• Journal of IKEEE
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• v.18 no.4
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• pp.636-644
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• 2014

This paper is to technically implement the sensing platform for Home-Wellness Robot. First, self-localization technique is based on a smart home and object in a home environment, and IOT(Internet of Thing) between Home Wellness Robots. RF tag is set in a smart home and the absolute coordinate information is acquired by a object included RF reader. Then bluetooth communication between object and home wellness robot provides the absolute coordinate information to home wellness robot. After that, the relative coordinate of home wellness robot is found and self-localization through a stereo camera in a home wellness robot. Second, this paper proposed fuzzy control methode based on a vision sensor for approach object of home wellness robot. Based on a stereo camera equipped with face of home wellness robot, depth information to the object is extracted. Then figure out the angle difference between the object and home wellness robot by calculating a warped angle based on the center of the image. The obtained information is written Look-Up table and makes the attitude control for approaching object. Through the experimental with home wellness robot and the smart home environment, confirm performance about the proposed self-localization and posture control method respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.463-472
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• 2018

The aim of this pilot survey was to investigate the presence status, usage problems, and improvement needs of the upper extremity rehabilitation equipment(: UERE) in the department of occupational therapy(: OT) of hospital setting in Korea. The authors received a questionnaires of clinicians working in a department of OT hospital setting through a social network service. Responses of 72 were analyzed in the first questionnaire, and 47 were analyzed in the second questionnaire. In the first questionnaire, the presence status of 16 UERE was confirmed to be 29.2~97.2%, and the usage experience of 9 UERE in the second questionnaire was 36.2~97.9%. In the second questionnaire, UERE's usage problems were reported discomfort in 15(31.9%) of 47 therapists, and improvement needs were 23(49%). The usage problems of the 9 UERE questioned by open-ended questionnaire were uninteresting, easily damaged, level unadjustable, direction unadjustable, and inconvenient installation. The improvement needs were classified into digitization, durability, level adjustable, adjustable function, convenience. The present pilot survey identified the presence status and usage experience of UERE in the department of OT and could be used as a basis for the development of closed-ended questionnaire on usage problems and improvement needs of UERE.

• Journal of the Korean Geotechnical Society
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• v.33 no.4
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• pp.35-46
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• 2017

Most of high carbon fly ashes (HCFA) are discarded in landfills with high costs due to low recycling rate. This study aims to explore the geotechnical behaviors of HCFA mixtures reinforced with fiber and sand. A series of compaction test, unconfined compressive strength test and modified 1D consolidation test with bender element were performed. Specimens were prepared at their optimal moisture contents based on the results of compaction tests. The results of this study demonstrate that the inclusion of fibers to the matrix of HCFA increases unconfined compressive strength (UCS), strain at UCS, and maximum shear modulus ($G_{max}$) at a given void ratio. Reinforcement with sand increases UCS of HCFA; while the strain at UCS is irrelevant with sand fractions. Sand particles may disrupt the direct contacts between HCFA particles at low sand content, resulting in a decrease in $G_{max}$. However, it can be expected that the mixtures with sand content larger than 20% are in dense state; thus, $G_{max}$ of HCFA reinforced with sand shows greater value than that of unreinforced HCFA compacted with the same energy. Regardless of types of reinforcement, the compression index ($C_c$) of both fiber and sand reinforced HCFA is mainly determined by initial void ratio.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.37-45
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• 2014

An embedded length of monopile caused by a scouring should be evaluated to monitor the stability of offshore foundations, because offshore foundations are affected by horizontal load. The objective of this study is to evaluate the scouring around offshore foundation by using electrical resistivity and to estimate ground stiffness by using shear wave tomography. The electrical resistivity profiles and shear wave tomography were measured according to the scour depth of model ground prepared with sand and cement. Several electrodes and bender elements were used to measure the electrical resistivity and shear waves, respectively. The electrode sets are attached on the monopile surface and bender elements are arranged in $7{\times}7$ arrays by using nylone frames. The electrical resistivity profiles and shear wave tomography are acquired by laboratory experiment. Maximum scour depth was estimated by electrical resistivity profiles and the ground stiffness of model ground was estimated by shear wave tomography. This study suggests that the electrical resistivity profiles and shear wave tomography may be useful for monitoring the stability of the offshore foundations.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.130-136
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• 2008

목적: 방사성옥소 치료를 받는 많은 환자들이 장기간의 전처치와 격리 입원 동안에 신체적 불편함을 호소하므로 이를 줄여주기 위하여 첫째, 방사성옥소 치료 전 환자들이 저옥소식을 잘 지킬 수 있도록 도움을 주며 둘째, 4일간의 격리입원기간 동안 심리적 어려움과 신체 적불편함을 줄여줌으로써 환자의 만족도를 향상시키는 효과를 기대하고자 본 연구를 하였다. 대상 및 방법: 1. 연구자들의 브레인스토밍을 통해 환자들의 불편함을 파악하였다. 2. 방사성옥소 치료를 위해 입원한 환자 36명에게 입원 기간 동안 느낀 점을 기록하게 하고 이를 조사하였다. 3. 환자 퇴원시에 치료과정에 대한 만족도 설문을 문제점 개선 전 33명, 개선 후 22명에게 조사하였다. 결과: 문제점과 개선안을 도출하였으며 가능한 범위 내에서 개선활동을 실시하였다. 그리고 만족도 설문을 조사하였으며 개선 전 후를 비교하였다. 문제점으로 1) 저옥소식: 맛이 없다, 반찬 가려 먹기가 어렵다. 2) 치료병실 생활: 속이 메스꺼워 음식 섭취가 곤란하다, 병실이 춥다. 3) 호르몬제 투여중지: 전신이 나른하다, 몸이 붓는다가 도출되었으며 이를 해결하기 위한 개선 활동은 1) 입원 전 예약 시에 음식조절(저옥소식)에 대한 설명을 자세히 하였다. 2) 타부서와의 협의-협조사항(치료병실의 청결유지와 쾌적한 병실을 만들기 위해 16층 병동과 협의, 저옥소식 영양상담을 치료 과정중에 넣기 위해 영양과와 협의, 온열매트리스 설치와 보온이불 구입을 위해 시설팀과 협의 등)을 해결하려 노력했다. 3) 전반적인 개선활동(방사성옥소를 차질없이 구입, 치료병실의 치료 전 후 방사능오염 방지, 환자의 심리적 불안감 해소 등)을 하였다. 환자의 만족도 설문에 대한 개선 활동 전 후 비교 결과에서 '치료과정 전체에 대해 힘들었다'는 개선 전 후에 각각 80.6%, 81.8%로 큰 차이가 없었다. 또한 문제점으로 도출된 '저옥소식이 힘들었다'는 개선 전 후에 각각 24.1%, 27.8%로 역시 큰 차이가 없었다. 그러나 '병실생활이 힘들었다'는 개선 전 후에 각각 48.3%, 72.2%로 큰 차이를 보였다. 그리고 '호르몬 투여중지로 인해 힘들었다'는 개선 전 후에 각각 27.6%, 0%로 큰 차이를 보였다. 고찰 및 결론: 환자들의 불편함을 줄여주기 위하여 연구자들의 개선활동이 있었고 그 중에서 입원병실의 생활환경이 특히 향상되었다. 그러나 결과에서 '병실생활이 힘들었다'에 대한 답의 비율은 오히려 더 높아졌다. 이는 '호르몬 투여 중지로 힘들었다'로 답하는 환자의 비율이 상대적으로 줄었기 때문에 높아진 것으로 생각되었다. 방사성옥소 치료로 인해 생길 수밖에 없는 신체적 반응 때문에 대부분의 환자들은 항상 힘들었다고 할 것이다. 만족도 개선 활동으로 환자의 힘든 치료과정을 완전히 해소시켜 줄 수는 없었으나 환자입장에서 생각할 수 있게 된 계기가 되었으며 좀 더 향상된 치료환경을 제공하는 기회가 되었다.

• Korean Security Journal
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• no.17
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• pp.91-107
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• 2008

This study aims to grasp the general conditions regarding university students in security related majors in Korea. Followings will be covered here: what motivated them to choose those majors, hw much are they git jobs through the education, what is their conscioucness on their majors, jobs, and courses like, and what effects their job preference. And ths study also aims at helping the student with their future plans such as admission to a school of higher grade and choosing their job. For this study, we distributed 340 copies to the students in security related majors at 4 four-year colleges and 1 two-year college, and collected 298 copies by means of quota sampling method. For collected questionnaires, we used individual T-test verification and one-way ANOVA analysis to grasp the situation. Significance stabdard for the test results was set as p<0.05. Followings are the test results. The results on analysis of satisfaction rate on their curriculums, classes, and majors show that students in security-related majors showed different satisfaction rate and different averages according to their sex and the year of the college. In the analysis on the relationship between major education and employment of students in security-related majors, the result of curriculum improvement and scholaril attainments analysis showed statistically significant relation. When students in security-related majors were surveyed on their consciousness of their future plans such as getting jibs, two-year college students had more certificates of qualification for employment than four-year college students.