• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1473-1474
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• 2008

In the total knee arthroplasty (TKA), kinematic benefic of a mobile-bearing total knee prosthesis is still arguing. Main reasons for implant failure are loosening and polyethylene wear and should be solved with new designs with mob ile bearings. The kinematics of the knee prosthesis also affects the implant failure. Recently, a second generation of p rostheses with a mobile-bearing was developed. The current study aimed to assess the kinematic path of the 2nd generation mobile knee prosthesis compared to the normal knees. Using 3D/2D registration method, CT-derived 3D knee models were fitted to sequential 2D X-ray images during knee flexion. 3D kinematics of the femur and the tibia were analyzed. The 2nd generation mobile-bearing TKA prosthesis (e.motion, Aesculap, Germany) knees showed less external rotation and knee flexion range compared to the normal knee, but the trend of external rotation was similar each other.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.261-267
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• 2021

As the number of Coronavirus Disease-19 (COVID-19) patients increases in a global pandemic situation, the usefulness of mobile computed tomography (CT) is gaining attention. Currently, mobile CT follows the basic safety and essential performance evaluation criteria of whole-body or limited-view X-ray CT in order to obtain device approval and evaluation in the Republic of Korea. Unlike stationary CT, mobile CT is not operated in shielded areas but rather areas such as intensive care units, operating rooms, or isolation rooms. Therefore, it requires a different basic safety and essential performance evaluation standard than stationary CT. In this study, four derived basic safety evaluation criteria related to electrical, mechanical, and radiation safety were included (dose indication test, protection against stray radiation, safety measures against excessive X-rays, half-value layer measurement); and seven essential performance evaluation criteria were included (tube voltage accuracy, mAs accuracy, radiation dose reproducibility, CT number of water, noise, uniformity, and spatial resolution); total eleven basic safety and essential performance evaluation criteria were selected. This study aims to establish appropriate basic safety and essential performance evaluation criteria for simultaneously obtaining images with diagnostic value and reducing the exposure of nearby patients, medical staff, and radiologic technologists during the use of mobile CT.

• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.117-122
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• 2017

The purpose of this study is to prevent infection in the hospital by computed radiography portable and to provide basic data on infection-related education by investigating bacterial contamination level of computed radiography portable equipment using IP cassette. The results suggest that IP cassette No. 1 is infected with CNS and VRE, no. 2 with CNS, No. 3 with CNS and Pseudomonas aeruginosa, No. 4 with CNS, No. 5 with CNS and Bacillus sp., and No. 6 with enterococcus faecium. Enterococcus faecium and bacillus sp. were detected from the IP reader and Acinetobacter baumannii was detected on the mobile handle; Bacillus sp. on the control buttons, CNS and Bacillus sp. from the irradiation control handle, Acinetobacter baumannii on the x-ray generation switch, and CNS on the barcode scanner. In addition, Bacillus sp. Acinetobacter baumannii was found on the IP cassette mobile table and CNS and bacillus sp. were found on the lead apron. Acinetobacter baumannii and CNS were detected from the medical gloves worn by a radiological technologist during radiography. This suggests that IP cassette should be sterilized after use as it can hand over bacteria to IP reader and IP mobile table. Medical gloves that are in direct contact with patients should also be replaced after using them once and other supplies such as x-ray generation switch and lead apron should thoroughly be sterilized to prevent infection due to radiography as they are in a lot of contact with patients.

• Journal of radiological science and technology
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• v.27 no.4
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• pp.37-41
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• 2004

Purpose : Raise ability cultivation in presence at a sicked business by performance management estimation of device through measurement. Also Learn a technology that measure exact tube voltage, exposure time, output dose. And it is to grasp photofluorography X-ray generator existing circumstances using at hospital. Material & Method : Investigated Photofluorography X-ray generator(inside, outside each 10) of 10 university hospitals using tube voltage, exposure time, output dose measuring instrument. Result : Photofluorography device that tube voltage correctness is incongruent by examination PAE decision came out 3, and at exposure time correctness examination 2 incongruent, Also 3 that calculate coefficient of variation about exposure in repeatability examination of exposure were incongruent. Inappropriate photofluorography device is 5 outside hospital(mobile unit) and the thing in hospital was 3 in 3 kind of efficiency test. It appeared high that photofluorography device outside hospital is more incongruent than thing in hospital. Conclusion : May ready situation that can offer patient medical service of good quality by radiation exposure reduction, image quality administration, retake decrease etc. by keeping performance of Photofluorography device. Therefore, is considered that need on-time efficiency test.

• Journal of Veterinary Clinics
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• v.37 no.1
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• pp.15-22
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• 2020

This study investigated the effectiveness of radiation safety rules in animal hospital and the awareness and behavior of veterinary radiation workers. With the questionnaires, the data was collected from randomly selected veterinarians in animal hospitals and animal medical imaging centers. Collected data were about radiation device, shielding device, regulations, safety management, education, knowledge, behavior and awareness. Frequency, correlation and multiple regression analysis were performed. The medical devices related with radiation in animal hospital were X-ray (59%), CT (15%), fluoroscopy (12%), mobile X-ray (12%) and others (2%). The number of people using radiation shielding device is high. The answers were low on knowing radiation related regulation and receiving radiation protection education. The group with higher knowledge and awareness shows positive correlation with safety behavior. The increase of use of the radiation related medical devices in veterinary hospital causes the increase of radiation exposure risk. This study suggests that radiation safety management system and policies need to be developed to protect radiation workers and give them correct information and consciousness.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.430-432
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• 2005

PDA는 작은 몸체로 이동성 및 편리성 등이 PC보다 뛰어나지만, 처리 속도가 상대적으로 느리기 때문에 해상도가 큰 이미지, 높은 처리 속도를 요구하는 작업 등을 처리하기에는 효율성이 낮은 문제점이 있다. 또한 정보를 Display할 수 있는 액정이 매우 작아서 환자와 관련된 의료 영상 즉, MRI 사진이나 X-ray 사진 등을 자세히 보기에는 현재의 기술력으로는 매우 어렵다. 그리고 특히 다수의 PDA와 PC 클라이언트의 데이터 요청으로 인한 서버의 과부하 문제 또한 모바일 진료시스템의 발전에 걸림돌이 되고 있다. 따라서 본 논문에서는 처리 속도와 Display의 제한을 대처하기 위하여 모바일 다중처리 시스템과 작업 이양 시스템을 구성하기 위한 하나의 방법론을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1203-1206
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• 2006

무선 인터넷이 보급됨에 따라 개인 휴대용 단말 장치(PDA)와 같은 모바일 PC를 이용하여 실시간으로 Server에 접속, 의료정보 및 환자 정보 등을 볼 수 있다. 여기서 PDA는 작은 몸체로 이동성 및 편리성 등이 PC보다 뛰어나지만, 처리 속도가 상대적으로 느리기 때문에 해상도가 큰 이미지, 높은 처리 속도를 요구하는 작업 등을 처리하기에는 효율성이 낮은 문제점이 있다. 또한 정보를 Display할 수 있는 액정이 매우 작아서 환자와 관련된 의료 영상 즉, MRI 사진이나 X-ray 사진 등을 자세히 보기에는 현재의 기술력으로는 매우 어렵다. 특히 다수의 PDA와 PC 클라이언트의 데이터 요청으로 인한 서버의 과부하 문제 또한 모바일 진료시스템의 발전에 걸림돌이 되고 있다. 따라서 본 논문에서는 처리 속도와 Display의 제한을 대처하기 위하여 모바일 다중처리 시스템과 작업 이양 시스템을 구성하기 위한 하나의 방법론을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.781-784
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• 2005

현재 모바일 시스템에서는 무선 인터넷이 보급됨에 따라 개인 휴대용 단말 장치(PDA)와 같은 모바일 PC를 이용하여 실시간으로 Server에 접속할 수 있다. 예를 들면 모바일을 이용한 진료 시스템에서는 원격으로 임상 정보 및 환자 정보 등을 볼 수 있다. 모바일 PC로 이러한 정보를 볼 수 있다는 것은 일반 PC로 진료 시스템에 접속하여 사용했었던 기존의 방식보다 편리성, 이동성 면에서 매우 좋은 평가를 받고 있다. 그러나 휴대성을 목적으로 만들어진 모바일 PC는 작은 Display 장치로 인하여 진료에 한계가 있고 원격 통신을 하기에는 많은 Client의 요구를 한 Server에서 처리하기는 매우 힘들다. 따라서 본 논문은 이런 문제점을 개선하기 위하여 X-ray나 MRI 등의 진료 이미지를 다양한 Server에서 처리하여 단말 장치에 전송하고 효율적인 다중처리시스템을 제안한다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.6
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• pp.252-256
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• 2015

Nitrogen oxides ($NO_X$) was emitted from flue gas of stationary sources and exhaust gas of mobile sources, can leads to various environments problems. Selective Catalysts Reduction (SCR) is the most effective $NO_X$ removal system. Commercial $V_2O_5-WO_3/TiO_2$ catalysts, usually containing $V_2O_5$ 0.5~3 wt%, $WO_3$ 5~10 wt%, and $V_2O_5$ is active in the reduction of $NO_X$ but also in the desired oxidation of $SO_2$ to $SO_3$. To reduce the amount of vanadium, using graphene matrix supported vanadium to synthesize nanocomposite. Then, we fabricated to 1 inch honeycomb type of SCR catalysts adding graphene-vanadium nanocomposite. The chemical-physical characteristics and the catalytic activity were performed by XRD, XRF, BET and Micro-Reactor (MR). As a result, the De-NOX performance was showed, similar to the commercial catalyst activity as 77.8 % and using nanocomposite catalyst as 77.1 % at $350^{\circ}C$.

• Korean Journal of Materials Research
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• v.26 no.12
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• pp.721-725
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• 2016

This work focuses on the electrical conduction mechanism in a lead free ($Na_{0.5}K_{0.5}NbO_3$ ; NKN) ceramics system with $LiNbO_3$ content of approximately critical concentration $x{\geq}0.2$. Lead free $(1-x)(Na_{0.5}K_{0.5})NbO_3-x(LiNbO_3)$, $NKN-LN_x$ (x = 0.1, 0.2) ceramics were synthesized by solid-state reaction method. Crystal structures are confirmed by X-ray diffraction. The electric-mechanical bond coefficient $k_p$ decreases and the phase transition temperature $T_c$ increases with increasing x content, as determined by dielectric and piezoelectric measurements. The value of the real dielectric constants ${\varepsilon}^{\prime}$ and $k_BT{\varepsilon}^{\prime\prime}$ showed anomalies around $T_c$ ($462^{\circ}C$ in the NKN-LN0.1 and $500^{\circ}C$ in the NKN-LN0.2). For the ionic conduction of mobile ions, the activation energies are obtained as $E_I=1.76eV$ (NKN-LN0.1) and $E_I=1.55eV$ (NKN-LN0.2), above $T_c$, and $E_{II}=0.78$ (NKNL-N0.1) and $E_{II}=0.81$ (NKN-LN0.2) below $T_c$. It is believed that the conduction mechanisms of NKN-LNx ceramics are related to ionic hopping conduction, which may arise mainly due to the jumping of $Li^+$ ions.