포트폴리오 收支論的 國際收支 調整 理論小考

李鐘燮,林龍澤 군산대학교 산업개발연구소 1987 産業開發硏究 Vol.6 No.-

DNA 감지를 위한 MOSFET형 전하검출센서의 제작 및 특성

정용택,김동선,류홍근,박혜정,신장규,최평,이종현,임근배 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

담즙정체성 간염의 임상적 양상

최선택,은종렬,임상우,김봉준,이헌주,구미진,최준혁 영남대학교 기초/임상의학연구소 2001 Yeungnam University Journal of Medicine Vol.18 No.1

Background: Cholestatic hepatitis is failure of bile to reach the duodenum with hepatocellular damage and no demonstrable obstruction of the major bile ducts. The prognosis is usually good with recovery in less than 4 weeks after withdrawal of the offending drug. However, a prolonged course lasting over 3 months is possible and, in rare cases, progression to ductopenia with development of a vanishing bile duct syndrome occurs. A differential diagnosis with other causes of Chronic liver disease is needed. Materials and Methods: From January 1991 through Jaunary 2000, 14 patients diagnosed as cholestatic hepatitis by liver biopsy were inclouded. The possible causative drug, clinical features, laboatory findings, and progression of cholestatic hepatitis were evaluated. The semiquantitative study of liver lesions was performed by two independent observers. Results: Causes of cholestatic hepatitis are 5 cases of oriental medicine, 3 cases of anti-tuberculosis medication, 1 case of ticlopidine and antibiotics and 4 cases of unknown causes. The clinical features of cholestatic hepatitis were jaundice, itching, urine color change, and general weakness. During 6 to 30 months, LFT of 5 patients showed prolonged elevation. Elevated total cholesterol ≥250 mg/dL in 6 patients, pheripheral blood eosinophilia in 5 patients, auto-antibody positive in 6 patients were observed respectively. The biopsies showed intralobular bilirubinostasis with a mixed portal inflammatory infiltration. Conclusion: In cholestatic hepatitis. durations of abnormal LFT are variable regardless of causative drugs. If cholestatic hepatitis progresses toward chronic course, viral hepatitis, primary biliary cirrhosis, and autoimmune hepatitis should be differentially diagnosed and sequential liver biopsies are needed.

음향방사로 인한 주기구조물에의 모우드 해석

박상기,임경택,이동하,김택현,김종태 朝鮮大學校 機械技術硏究所 1999 機械技術硏究 Vol.2 No.2

In this study, the mode shape of infinite fluid loaded plate is examined. The stiffeners are assumed to be equally spaced and exert only force on the Plate. The response of a fluid loaded ㄷ-type stiffened plate to a convected harmonic pressure and the far field radiation Produced by a point force excitation have been found by using Fourier transforms, a method which is particularly useful when fluid loading is included. At low and high frequencies the far field Pressure for a point excited stiffened plate is dominated by the fluid properties and the properties of the plate at the point of excitation. Mode in the far field pressure is found at the given direction of scattering frequencies, and in these frequencies the stationary phase wave frequencies are found to coincide with the free wave propagation constants for the stiffened plate. Also, the variation in the modes of the sound pressure level is increased with the increases of the bay space and in the bay area

안와골절의 외과적 접근에 대한 증례보고

민승기,이은택,오승환,이동근,고세욱,송종민,최성림 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.3

The Orbital fracture which is often combined with midface fracture can cause decreased visual acuity, limitation of eyeball movement, diplopia, enophthalmos, etc. Traumatic orbital fracture causes change of orbital volume, results in diplopia and enophthalmos thus, accurate repositioning of displaced bone and reconstruction of orbital defect with autogenous materials(cranial, rib, iliac bone, cartilage and fascia lata) or alloplastic materials(gelatin film, polyglactin mesh, methylmethacrylate, Teflon, silicone, Supermid, hydroxyapatite and metal). The key point of reconstruction of orbit is accurate repositioning of displaced orbital floor, lateral, medial orbital wall and sufficient bonegraft in anatomical defect. As this cases, we obtained good results through transconjunctival and coronal approach who were required orbital reconstruction. Also, we accurately diagnosed orbital fracture with C.T., 3D model and good result for orbital reconstruction with sufficient parietal block bone graft during average 16.8 months follow-up.

급속응고된 N-type Bi₂Te_(2.75)Se_(0.15) 열전재료의 미세조직과 열전특성에 미치는 압출비의 영향

김태경,이상일,임종호,손현택,김택수,천병선 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.1

The n-Type thermoelectric compounds of Bi₂Te_(2.75)Se_(0.15) doped with 0.1 wt% SbI₃ were fabricated by gas atomization process and extruded under ratio of 16:1 and 28:1 at 450℃. The effect of extrusion ratio on the microstructures and thermoelectric properties were investigated by a combination of microscopy, XRD and thermoelectric properties. Grains of extruded bars are smaller than those of heated powder at extrusion temperature (450℃) due to the dynamic recrystallization but with increasing the amount of plastic deformation, grains of specimen extruded with 28:1 were slightly coarse. The compressive strength of hot extruded bar under 28:1 is 160 MPa and with decreasing the extrusion ratio to 16:1, the value is 250 MPa. The Seebeck coefficient a and electrical resistivity p were decreased with increasing ratio, while thermal conductivity x was increased. this results from decrease of carrier scattering and increase of carrier mobility. Extruded bar under ratio of 16:1 shows the higher value of figure of merit (Z=2.50x10^(-3)/K) than that of 28:1 (Z=2.07x10^(-3)/K). (Received June 24, 2004)

키보드 형태가 컴퓨터 신경행동검사에 미치는 영향

전만중,김창윤,정종학,임우택,사공준 大韓産業醫學會 2004 대한직업환경의학회지 Vol.16 No.2

목적 : 컴퓨터에 대한 친숙도가 컴퓨터 신경행동검사에 미치는 영향을 평가하고, 컴퓨터 신경행동검사를 수행할 때 키보드 형태의 영향을 평가하며, 컴퓨터에 대한 친숙도와 신경행동검사 결과의 관련성에 키보드 형태의 영향을 평가함으로서 컴퓨터에 대한 친숙도의 영향을 가장 적게 받는 신경행동검사 항목을 선택하고 향후 컴퓨터 신경행동검사를 효과적으로 사용하는데 적합한 키보드의 형태를 결정하기 위하여 수행되었다. 방법 : 컴퓨터에 대한 친숙도는 한글의 분당타자속도에 따라 컴퓨터를 사용한 경험이 전혀 없는 군(1군, 24명, 타자속도 0자/분), 컴퓨터를 사용하긴 하나 익숙지 않은 군(2군, 21명, 타자속도 200자/분 미만) 및 컴퓨터를 능숙하게 다루는 군(3군, 25명, 타자속도 200자/분 이상)으로 나누고 성별, 연령 및 학력을 조사하였다. 신경행동검사는 컴퓨터 신경행동검사 프로그램인 SPES-K를 이용하여 단순반응시간, 숫자더하기, 부호숫자짝짓기 및 손가락 두드리기 순으로 시행하였으며, 일반적으로 컴퓨터에 사용되는 106개의 키를 가진 키보드(1형), 일반적인 키보드를 검사에 사용되는 17개의 키(10개의 숫자키, 4개의 화살표 키, 양쪽 Ctrl키, 스페이스 바)만 두고 나머지 키는 제거한 키보드(2형) 및 11개의 키(10개의 숫자키, 스페이스 바)로 된 특별히 제작된 키보드(3형)를 이용하여 검사하였다. 결과 : 대상자들의 평균 연령은 1군이 49.9세, 2군이 33.6세 및 3군이 28.9세였으며, 각 군간의 유의한 차이가 있었다(F=58.88, p<0.001). 남녀의 구성은 1군, 2군 및 3군에서 유의한 차이가 없었으며, 교육수준은 1군이 평균 10.3년, 2군이 15.3년 및 3군이 17.1년으로 유의한 차이가 있었고(F=39.605, p<0.001), 분당 한글 타수는 1군은 0회, 2군은 평균 79.2회 및 3군은 224.2회였다(F=165.983, p<0.001). 단순반응시간, 숫자더하기, 손가락 두드리기에서 연령과 교육수준을 보정한 평균반응시간과 반응시간의 표준편차 및 오답수는 세 가지 키보드 형태 모두에서 세 군간의 유의한 차이는 없었다. 부호숫자짝짓기에서는 1형 키보드 형태에서 연령과 교육수준을 보정한 후 1군은 3448msec, 2군은 2520msec 및 3군은 2753msec로 1군과 2군 사이에서 유의한 차이가 있었다(F=3.347, p=0.041, Bonferroni F 사후검정). 그러나 2형 키보드 형태나 3형 키보드 형태에서는 세 군간의 유의한 차이가 없었다. 부호숫자짝짓기의 오답수는 연령과 교육수준을 보정한 후 세 가지 키보드 형태 모두에서 세 군간의 유의한 차이가 없었다. 신경행동검사 결과를 한글 타자속도에 따른 각 군내로 한정하여 세 가지 키보드 형태간의 차이를 비교하면 단순반응시간, 숫자더하기 및 손가락 두드리기의 검사 결과는 세 가지 키보드 형태간에 유의한 차이는 없었다. 부호숫자짝짓기의 경우 평균반응시간의 표준편차 및 오답수는 유의한 차이가 없었으나, 평균반응시간이 1군에서 1형 키보드로 검사를 한 경우 4630 msec, 2형 키보드로 검사한 경우 3265 msec 및 3형 키보드로 시행한 경우 3519 msec로 1형 키보드와 2형 키보드간 및 1형 키보드와 3형 키보드간에서 유의한 있었다(F=6.197, p=0.003, Bonferroni F 사후검정). 2군의 경우에는 세 가지 형태의 키보드 간에 유의한 차이가 없었고, 3군의 경우에는 1형 키보드로 검사한 경우 1915 msec, 2형 키보드로 검사한 경우 1761 msec 및 3형 키보드로 시행한 경우 1784 msec로 1형 키보드와 2형 키보드간 및 1형 키보드와 3형 키보드사이에서 유의한 차이가 있었다(F=8.950, p<0.001, Bonferroni F 사후검정). 결론 : 컴퓨터에 대한 친숙도나 키보드에 의한 영향이 많다고 생각되는 근로자 집단에 대해 컴퓨터 신경행동검사를 수행하는 경우에는 단순반응시간, 숫자더하기 및 손가락 두드리기와 같은 검사항목이 다른 검사에 비해 타당성이 좋은 검사로 평가되었다. 그러나 컴퓨터에 대한 친숙도나 키보드 형태에 영향을 받는 부호숫자짝짓기의 경우 대상자의 컴퓨터에 대한 친숙도를 결과의 해석에 고려해야 할 것으로 생각되며, 부호숫자짝짓기의 타당성을 높이기 위해서는 적합한 키보드의 선택에 관한 고려가 필요할 것으로 생각된다. 즉 부호숫자짝짓기의 경우 일반적인 1형 키보드에 비해 컴퓨터에 대한 친숙도의 영향을 감소시키는 경향을 보인 2형과 3형의 키보드 사용이 권고된다. Objectives: A stratified cross-over study was conducted to evaluate the effects of familiarity with computer on the performance of computerized neurobehavioral tests. Effects of keyboard type on the relationship between familiarity with computer and performance of computerized neurobehavioral tests were also examined. Methods: We tested 70 persons classified into three groups according to degree of familiarity with computer: Group 1 was people with no computer competency, Group 2 had slight working experience on the computer, and Group 3 were highly competent and efficient on the computer. For each group, we executed 4 tests of the Korean version of the Swedish Performance Evaluation System (Simple Reaction Time, Addition, Symbol Digit, and Finger Tapping Speed). Three types of keyboard were applied for all three groups. Type 1 keyboard was a conventional layout with 106 keys. We removed the unused keys except for the 17 which were used in the test and remodeled the normal keyboard into Type 2 keyboard with 17 keys (10 numeric keys, 4 arrow keys, space bar, and both CM keys). Type 3 keyboard with 11 keys consisted of 10 numeric keys and the space bas was newly developed for the computerized neurobehavioral performance test. Results: It was found that Simple Reaction Time, Addition, and Finger Tapping Speed were not affected by familiarity with computer and type of keyboard. The mean reaction time of Symbol Digit adjusted by age and educational level with Type 1 keyboard was found to have significant difference among the three groups (F=3.347, p=0.041). The performance of Symbol Digit in Group 1 was found to be significantly lower than that in Group 2. The performances of Symbol Digit measured with Types 2 and 3 keyboards were not found to have significant differences among the thee groups. In Groups 1 and 3, the performances of Symbol Digit measured with Type 1 keyboard were found to be significantly lower than those of other keyboards. Conclusions: According to the above results, Simple Reaction Time, Addition, and Finger Tapping Speed have high priority over other neurobehavioral tests for the workers having varying degrees of computer familiarity. It is also suggested that familiarity with computer and keyboard type needs to be considered in interpretation of the performance of Symbol Digit. We recommended executing the computerized neurobehavioral test with keyboards 2 or 3 to reduce the effect of computer familiarity.

A high output magneto-mechano-triboelectric generator enabled by accelerated water-soluble nano-bullets for powering a wireless indoor positioning system

Lim, Kyung-Won,Peddigari, Mahesh,Park, Chan Hee,Lee, Ha Young,Min, Yuho,Kim, Jong-Woo,Ahn, Cheol-Woo,Choi, Jong-Jin,Hahn, Byung-Dong,Choi, Joon-Hwan,Park, Dong-Soo,Hong, Jae-Keun,Yeom, Jong-Taek,Yoon, The Royal Society of Chemistry 2019 ENERGY AND ENVIRONMENTAL SCIENCE Vol.12 No.2

<P>A high-performance magneto-mechano-triboelectric nanogenerator (MMTEG) was demonstrated by introducing accelerated water-soluble nano-bullet modified nanostructures to convert a gentle magnetic field into electric energy for powering an indoor wireless positioning system. NaCl salt nanoparticles were accelerated by an aerosol deposition (AD) process to collide on a perfluoroalkoxy (PFA) film with a high kinetic energy for the formation of a complicated nanomorphology on the triboelectric active surface. Under an alternating current (AC) magnetic field of 7 Oe, the MMTEG generated an open-circuit peak-to-peak voltage (<I>V</I>pp) and a short-circuit current of 708 V and 277 μA, respectively. The harvesting device also presented a maximum peak power of 21.8 mW as well as a continuous AC output power of 4.8 mW (4.8 mJ per second). A self-powered indoor IoT positioning system was constructed by integrating the MMTEG, a power managing circuit, a storage element, and an IoT Bluetooth beacon. The electric energy from the MMTEG device enabled continuous operation of a beacon device, and we successfully confirmed the accurate location of the installed wireless positioning system, subsequently resulting in transmission of our indoor position to the main monitoring computer. Lastly, the MMTEG generated an open-circuit <I>V</I>pp and a short-circuit current of 330 V and 23 μA, respectively, near a 60 Hz power cable connected to home appliances, which were large enough to turn on 108 blue light emitting diodes (LEDs).</P>

Preparation and Characterization of Natural Material Extracted from Germinated Brown Rice

Lim, Ki-Taek,Choi, Jeong Moon,Lim, Won-Chul,Kim, Jangho,Cho, Hong-Yon,Chung, Jong Hoon Korean Society for Agricultural Machinery 2014 바이오시스템공학 Vol.39 No.3

Purpose: The aim of this study was to prepare and evaluate a natural material extracted from germinated brown rice (GBR). Herein, we evaluated whether the natural material could positively activate the biological effects seen during bone formation, including enhancement of metabolic activity, osteogenesis, and the expression of vascular endothelial growth factor (VEGF), one of the growth factors in human osteoblast-like cells. Methods: The natural material was created by a hot water extraction process after being soaked for 2~3 days in tap water and dried at $50^{\circ}C$. The material was characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transformed infrared (FTIR) spectroscopy. The biological behaviors of the material were also investigated; we performed tests to assess cell cytotoxicity, metabolic activity, osteogenic markers related to bone formation, and VEGF. Results: The EDX, XRD, and FTIR results for the natural material indicated the presence of organic compounds. The natural material caused positive increases in cell metabolic activity and mineralized bone formation without cytotoxicity. The protein levels in the extract for the $6.25{\mu}g/mL$, $12.25{\mu}g/mL$, $25{\mu}g/mL$, $50{\mu}g/mL$, and $100{\mu}g/mL$ groups were significantly different from that for the control. Conclusions: The GBR-based natural material was easy to prepare and had characteristics of a potential biomaterial. The biocompatibility of this natural material was evaluated using in vitro techniques; our findings indicate that this novel material is promising for agricultural and biological applications.

Preparation and Characterization of Natural Material Extracted from Germinated Brown Rice

( Ki Taek Lim ),( Jeong Moon Choi ),( Won Chul Lim ),( Jang Ho Kim ),( Hong Yon Cho ),( Jong Hoon Chung ) 한국농업기계학회 2014 바이오시스템공학 Vol.39 No.3

Purpose: The aim of this study was to prepare and evaluate a natural material extracted from germinated brown rice (GBR). Herein, we evaluated whether the natural material could positively activate the biological effects seen during bone formation, including enhancement of metabolic activity, osteogenesis, and the expression of vascular endothelial growth factor (VEGF), one of the growth factors in human osteoblast-like cells. Methods: The natural material was created by a hot water extraction process after being soaked for 2~3 days in tap water and dried at 50°C. The material was characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transformed infrared (FTIR) spectroscopy. The biological behaviors of the material were also investigated; we performed tests to assess cell cytotoxicity, metabolic activity, osteogenic markers related to bone formation, and VEGF. Results: The EDX, XRD, and FTIR results for the natural material indicated the presence of organic compounds. The natural material caused positive increases in cell metabolic activity and mineralized bone formation without cytotoxicity. The protein levels in the extract for the 6.25 μg/mL, 12.25 μg/mL, 25 μg/mL, 50 μg/mL, and 100 μg/mL groups were significantly different from that for the control. Conclusions: The GBR-based natural material was easy to prepare and had characteristics of a potential biomaterial. The biocompatibility of this natural material was evaluated using in vitro techniques; our findings indicate that this novel material is promising for agricultural and biological applications.