영상 인식을 활용한 실내 모바일 물류 로봇의 자율협업 시스템

이주혁,이규만 제어로봇시스템학회 2022 제어로봇시스템학회 국내학술대회 논문집 Vol.2022 No.6

토양 세척 후 발생하는 2차 폐수에서의 방사성세슘 제거 연구

이주혁,강재은,김원석 대한환경공학회 2020 대한환경공학회지 Vol.42 No.8

Objectives:Secondary wastewater is generated as the soil washing process proceeds to restore contaminated soil near the nuclear power plants (NPPs). In this study, we tried to evaluate the possibility of removing radioactive cesium from secondary wastewater through the adsorption process using illite. Methods:To treat radioactive cesium present in wastewater, as an adsorbent, we used illite collected from Yeongdong, Chungbuk, and weathering illite artificially weathered by high temperature and acid treatment (60℃, 0.01 M HCl). Before and after weathering, the adsorption rate of illite at low concentrations of cesium and the desorption rate of adsorbents were compared and evaluated using a 1.5 ppm of competitive potassium ion similar to that of groundwater. Results and Discussion:When the illite was artificially weathered, the amount of frayed edge sites increased as the interlayer ions in the illite eluted. As a result of the adsorption and desorption experiments, it was confirmed that the adsorption rate of weathering illite increased by about 11% in acid condition (pH 3) and about 26% in neutral condition (pH 6.2), and the desorption rate of weathering illite decreased by about 6% in acid and neutral conditions, compared to Yeongdong illite. Yeongdong illite and weathering illite showed higher adsorption rate under neutral condition than acidic condition, because the surface of the illite became negatively charged at high pH so the reactivity with cesium present as a cation increased. Conclusions:The artificial weathering process has improved the performance of illite as an adsorbent. We expect that weathering illite can be used as an effective adsorbent for the removal of radioactive cesium from NPP. 목적:본 연구에서는 원자력발전소 인근 방사성 세슘으로 오염된 토양의 복원을 위한 토양 세척공정에서 발생되는 2차 폐수 중의 방사성세슘을 일라이트를 이용한 흡착공정을 통해 제거 가능성을 평가해 보고자 하였다. 방법:본 연구에서는 폐수 중 존재하는 방사성세슘을 처리하기 위해 흡착제로 충북 영동에서 채취한 영동 일라이트와 이를 고온산처리(60℃, 0.01 M HCl)하여 인위적으로 풍화시킨 풍화일라이트를 이용하였다. 풍화 전후 저농도 세슘(1 ppm)에서의 일라이트의 흡착율을 비교하였으며, 경쟁 이온인 칼륨(1.5 ppm)을 이용하여 흡착제의 탈착율을 비교 및 평가하였다. 결과 및 토의:일라이트를 인위적으로 풍화시키면, 일라이트 내 층간 이온이 용출되면서 풍화된 모서리면의 양이 증가하였다. 흡착 및 탈착 실험 결과, 풍화일라이트의 흡착율은 영동 일라이트보다 산성 조건(pH 3)에서는 약 11%, 중성 조건(pH 6.2)에서는 약 26% 증가하였으며, 탈착율은 산성 조건(pH 3)과 중성 조건(pH 6.2)에서 약 6% 감소하는 것으로 나타났다. 영동 일라이트와 풍화일라이트는 산성 조건보다 중성 조건에서 흡착율이 높게 나타났는데, 이는 높은 pH에서 일라이트의 표면이 음전하를 띠게 되어 양이온으로 존재하는 세슘과의 반응성이 증가하였기 때문이다. 결론:인위적인 풍화과정울 통하여 흡착제로써의 일라이트 성능을 개선시켰으며 이는 원자력발전소에서 발생하는 방사성세슘 제거를 위한 효과적인 흡착제로 활용될 수 있음을 시사한다.

잠수병으로 인한 뇌손상의 전산화단층촬영 소견

이주혁 대한영상의학회 1989 대한영상의학회지 Vol.25 No.4

Mechanism of brain injury in dysbaric diving accident is controversial but likely are due to arterial gas embolization. We reviewed 6 CT cases among 4 patients of brain injury in dysbaric diving accident and evaluated the role of CT. Among 4 patients we can see diffuse low density in cerebral white matter in 2 patients focal low density in cortical and subcortical area of right frontal and left temporopatieral lobe in 1 cases and normal CT finding in 1 case. And we convinced that combination of MRI and follow up CT is useful for the evaluation of neuropathologic process and progress of injury during management.

금속성 동맥류 클립에 의한 자기공명영상의 인공물에 관한 연구

이주혁 대한영상의학회 1992 대한영상의학회지 Vol.28 No.2

To investigate MR artifacts induced by metallic implants, scans were obtained using both the ferromagnetic Drake clip and the nonferromagnetic Yasargil clip. Scans were taken through the area of clips using geometrical phantom. The MRI was performed by spin echo technique and gradient echo technique on both 2.0T and 0.5T MR unit. The authors evaluated the nature and differences of artifacts in each sequence and parameter. Artifacts induced by both clips were noted in the direction of frequency encoding gradient, and consisted of a region of signal loss abutted on one side by a curvilinear region of bright signal. Geometric distortion of image was marked in the Drake clip, but was minimal in the Yasargil clip under both 2.0T and 0.5T. Artifacts were more pronounced in the gradient echo technique than those of the spin echo technique on both 2.0T and 0.5T. Artifacts there were no differences in the nature of artifacts induced by the Drake clip among each parameter in the spin ec o technique under 2.0T, artifacts were slightly more pronounced in T2 weighted image under the 0.5T field, but no differences were found in the nature of artifacts induced by the Yasargil clip in the spin echo technique under both the 2.0T and 0.5T fields. Marked artifacts were induced through the small area of the Drake clip which were included in the scan plane, but induced artifacts were small when a small area of the Yasargil clip was included in the scan plane. It seemed likely that artifacts were slightly more pronounced in the 2.0T than the 0.5T field in both clips, but objective evaluation of the difference was difficult. In conclusion, these results can be an essential basis for the interpretation of MR images of patients with metallic implants.

Processing of porous hydroxyapatite scaffolds containing calcium phosphate glass-ceramics for bone tissue engineering

이주혁,최홍준,윤석영,김병규,박홍채 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.4

Highly porous hydroxyapatite (HA) scaffolds containing calcium phosphate glass-ceramics with large pore size and improved compressive strength have been prepared using a combined processing route of polymer sponge and freeze/gel-casting. Tertiary-butyl alcohol (TBA) was used as a solvent. The sintered scaffolds were characterized in terms of microstructure, physical and mechanical properties. A reticulated structure with large pore size of 220-300 µm was formed on burn-out of polyurethane foam where the struts consisted of a few intergranular small-sized pores (< 2 µm) formed by freeze/gel-casting. The addition of glass-ceramics seemed to lead a matrix phase to partial liquid phase sintering and thus the strut structure became more dense with the small size reduction of coarsened pores consisting of reticulated structure. As a consequence, the compressive strength was improved. Also, with the addition of 10 wt.% glass-ceramics the in vitro bioactivity of the scaffolds was further enhanced.

우리 시대의 히포크라테스가 나타나길 바라며...

이주혁 제3시대그리스도교연구소 2018 제3시대 Vol.126 No.-

성형외과 영역에서의 디지털 임상사진 촬용기술

이주혁,김준표,홍성희 大韓成形外科學會 2004 Archives of Plastic Surgery Vol.31 No.2

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이주혁 대한영상의학회 1993 대한영상의학회지 Vol.29 No.6

This study was designed to evaluate the potential application of MRI in differentiating static blood from thrombus, age-related changes of thrombus and the signal differences of the intravascular thrombus in various pulse sequences. External jugular vein was ligated at both upper and lower ends to form a static blood column, and thrombin was injected into the column to cause venous thrombosis in a total of 15 mongrel dogs. The MR images were obtained with T1-and T2-weighted spin echo and gradient echo techniques, immediately after the formation of static blood a nd after 2 hour, 1 day, 1 week, 2 weeks and 4 weeks of the formation of thrombus at a 2.0T MR unit. The signal intensities of the thrombus and adjacent muscles were compared stubjectively, and the signal intensity ratio was compared objectively by the measurement of the signal intensities using a cursor, The MRI findings were compared with histologic findings. The signal intensities of static blood were hyperintense in all pulse sequences, and those of 2-hour, 1-day and 1-week-old thrombi were hyperintense in all pulse sequences. The number of experimental thrombi which showed isointensity on T1-and T2-weighted image, and hypointensity on gradient echo image increased as thrombi aged. The signal intensities of 2-week-old thrombus were isointense on T1-weighted image, hyperintense on T2-weighted image, and hypointense on gradient echo imate, while those of 4-week-old thrombus were isointense on T1-weighted and T2-weighted image, and hypointense on gradient echo image in most experimental thrombi. There was a tendency to decrease in a signal intensity ratio as thrombi aged on T1 -weighted, T2-weighted and gradient echo images(p<0.01) Histologically, thrombus was not formed and lumen was filled with many red blood cells (RBCs) in 2-hour-old specimen, but fibrin mesh was visible and RBCs decreased in number in 1-day-old specimen, In 1-week-old specimen, vessel was contracted and lemen was filled with thombus, RBSs, platelets, many fibrins and capillary-like strucrutes. The histologic findings of 2 -week - old thrombus were similar to those of 1-week-old one except calcification. In 4-week-old specimen, vessels were contracted and lumen was obliterated with fibrosis and organization of the thrombus. Therefore, it is possible to diagnose thrombus, and to assess sequential changes of MRI findings of thrombus by using all pulse sequences, and these results can be essential bases for the interpretation of MR images of patients with venous thrombosis.

중소기업 중간관리자의 앙트러프러너십(entrepreneursdhip) 역량 증진 프로그램 설계

이주혁,박수홍,김두규,남기곤 한국기업교육학회 2012 기업교육과인재연구 Vol.14 No.2

The purpose of this research is that middle manager's entrepreneurship competence increasing program’s implementation of the draft, and application and responses from real field to determine it’s appropriateness. Entrepreneurship is attributed to entrepreneur's leadership, mind, will and spirit. But this research defines entrepreneurship is competence for the field in group. Through individual’s ability, technology, mind conviction, it can be externally executed to have special influence individual, groups, and society. Crazy, perculiar, eccentricity, spectacular originality, and to put these into start to create new result with propulsion and practicality as the basic component, with these components, a program which will allow development and spreading as the internalization of program’s prototype. Therefore, creativeness and practicality was set as the core value. The competency was to be defined as the base of technique, skills, ability with challenging, creative as job competency. Through core values of creativeness and practicality into practice, the core process of the program was performed. With systematic action learning and 3-dimention mind frame and etcetera, performance of activities and processes’ environmental support, and company plan written practice, the Entrepreneurship’s 4 different component, creativeness, thinking power, problem solving skills, strategic planning, communication amplification, were used to make the program’s draft. There were in-depth anlysis of previous papers, journal, literature, and web, and communications through phone calls, emails and interviews were made with middle manager's, directors, and team leaders. Additionally, entrepreneurship establishment, team leadership education process, manager education process, middle's education process, creativeness education process, new business plan and etcetera, business planning related process and etcetera, were made to increase the practicality of application in the field work. This research was processed through utilizing development research, multi-level verification method and professional group’s interviews of program details, to increase the feasibility. 본 연구는 기업의 운영과 발전에 중추적 역할을 담당하는 중간관리자들의 앙트러프러너십 역량 증진 프로그램을 설계함에 목적을 두고 있다. 이러한 연구목적 달성을 위해 우선 문헌 및 사례분석, 심층면접을 통해서 중간관리자를 대상으로 앙트러프러너십 역량의 하위요소를 도출하였고, 핵심가치 추출 및 구현을 위해 프로그램 모형의 핵심 프로세스와 프로세스 지원요소를 구안하였다. 전문가 형성평가를 통해 프로그램 설계안의 강점과 개선점을 도출하였고, 수정, 보완작업을 거쳐 최종 프로그램을 설계한 후 타당도 검증을 실시하였다. 그 결과 앙트러프러너십을 기존의 개념적 정의에서 벗어나 역량의 개념으로 볼 수 있었고, 앙트러프러너십의 하위요소인 창의적 사고력, 문제해결력, 전략적 기획력, 커뮤니케이션을 프로그램 내용 전반에 유기적으로 연결될 수 있도록 하였다. 또한 프로그램 구성에 있어 앙트러프러너십의 하위역량 요소를 바탕으로 하면서도 팀 활동 및 실천성을 담보할 수 있는 비즈니스 전반의 프로세스 과정을 포함한 내용으로 구성하였다. 프로세스의 진행단계와 앙트러프러너십의 하위요소 간의 관계성을 중심으로 사업계획서 작성이라는 결과물을 통해 아이디어 활용 및 실제 업무현장에서 활용할 수 있는 생명력을 갖출 수 있는 프로그램이 될 수 있는 가능성을 제시하였다.

마르크 샤갈의 작품에 표현된 조형적 특성 분석을 통한 네일 디자인 연구

이주혁,이유나,임희경 한국미용예술경영학회 2015 미용예술경영연구 Vol.9 No.1

Today nail art is simply fingernails, toenails Do not really manage to raise the nail of people receiving stress management and their being used as a means of self-expression that can express your personality. That is today's nail art fashion, beauty was a part of and further enhance the personal charm can increase the good feeling through them, and has a big role in the self-satisfaction. Fashion, beauty nail art place to catch a variety of designs and this area is expressed in the concept of a planned theme nail art and has been developed with various designs are required for this look. These social requirements are simply nail in the design or configuration works not only as a coloring being affected by social and artistic zeitgeist, and it also has a big role to play in exploring and trying new design foundation. In this study, only the centuries have passed since we produce nail design based on work analysis exploring the emblematic nature as the work of a magician Marc Chagall's color being talked about even now motif of looking at the transition course of his life and works and works . Marc Chagall works were a total of four works were selected on the basis of analysis of the design magazines, books, Web sites, papers relating thereto prior to selecting a motif. Themes and lines appear in the Selected works motif, cotton, color analysis was divided into grasp the characteristics of color through color distribution, color analysis to analyze the formative characteristic configuration of the original design was shown to work was the design. Production method works with colors, geometric patterns, cotton, inspired by the lines of gradient nail art techniques, flat art techniques, hand-painting techniques, and creates works using a UV gel technique. The results of this study different techniques and colors contained Chagall's work was creative nail design based on the future We expect a high quality variety of nail design has created hope.