光電 方法에 의한 MOS구조의 산화층내의 電荷分布 연구

심성엽,金末文,이동건,문영희 嶺南大學校 基礎科學硏究所 1993 基礎科學硏究 Vol.13 No.-

Charge trapping in the insulator of a metal-oxide-semiconductor (MOS) structure strongly influences photocurrents resulting from electron photoinjection from gate into this insulator. These electric characteristics are investigated by Przewlocki method for determination of trapped charge distribution in the dielectric of a MOS structure. Silicon dioxide films were grown thermally in a dry oxygen ambient at 1000℃ to a thickness of 2000Å on (100) 6-9Ωcm p-type Si Wafers. As a result, it is found that the negative charge distribution is an exponential profile of decay lengthλ=9.907×10??cm and trapped charge density N。=3.912×10??cm-₃in the dielectric of this MOS structure.

GC/NPD를 이용한 다성분 잔류농약의 동시분석

김우성,이선화,김상엽,정동윤,김재이,이영자,이홍재,정성욱,박흥재 한국환경과학회 2003 한국환경과학회지 Vol.12 No.10

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with fiorisil, and finally analyzed simultaneously the organophosphorus pesticides using GC/NPD, Ultra-2 and Ultra-1 fused silica capillary columns were used to separate and identify the products. Recovery of most analytes from soybean sample, taken from pesticide residues well, was greater than(80%) for all except(6) analytes. This method can simultaneously determine multiple pesticides with a high degree of accuracy and precision.

과잉 PbO에 따른 Pb(Mg, Nb)O₃-PbTiO₃계 세라믹스의 압전특성

김규수,백동수,윤광희,이두희,박창엽,윤현상 연세대학교 산업기술연구소 1993 논문집 Vol.25 No.1

In this study, the dielectric, piezoelectric and structual properties of PMN-PT system ceramics were investigated with respect to the variation of PbO addition amount and sintering temperature. The specimen with 1.0wt% PbO addition exhibits relatively good sintering and piezoelectric properties, which has the density with 97.36%, the coupling constant(kp) with the value of 47.44% and the piezoelectric ?? with ?? at sintering temperature 1000℃ respectively.

금합금의 프라이머 처리가 교정용 브라켓의 접착에 미치는 영향

류동범,권태엽,권용훈,김교한 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.3

The purpose of this study was to compare the bonding strength and the interfacial micromorphology of two surface modification of gold alloys in direct bonding of orthodontic brackets. Flat tab of cast gold alloys (n= 120) were subjected to either of two surface treatments: 1.50㎛ aluminum oxide sandblasting, and 2. sandblasting plus adhesive primer for noble metal. Orthodontic brackets (RMO Co.) were bonded directly with Superbond C&B (Sun Medical Co. Ltd.), or Transbond XT (3M Unitek), or Ortho One (Bisco). All specimens were stored in distilled water at 37℃ for 24 hours, and then the tensile bond strength testing was performed in a Instron test machine. Bond failure sites were classified by a modified Adhesive Remnant Index (ARI) system. The results showed that sandblasting plus adhesive primer for noble metal produced stronger bonds to gold alloy than sandblasting only in all cases (Superbond C&B, Transbond XT, Ortho One). Superbond provided significantly stronger bonds to gold alloy than the others. Bond failure of Superbond to sandblast only and sandblast plus adhesive primer for noble metal to gold alloy occurred at the bracket/adhesives interface, whereas bond failure of the others occurred at the gold/adhesive interface. The clinical implications of these findings are discussed.

북한의 군사지도,지휘체계: 당,국가,군 관계를 중심으로

김동엽 ( Dong Yub Kim ) 북한연구학회 2013 北韓硏究學會報 Vol.17 No.2

본 연구는 우리 국방백서에 나타나 있는 북한 군사지휘체계에 대한 의문과 비판에서 출발하여 북한 군사지도·지휘체계의 변화와 특징을 고찰하고 있다. 국방위원회를 정점으로 북한군사 지휘체계를 설명하고 있는 국방백서의 해석은 일면 북한 군사기구의 기능과 위상을 정확히 파악하지 못하고《인민무력부=국방부, 총참모부=합참》이라는 우리의 군사지휘체계 틀에 북한의 군사기구를 그대로 대입한 오류를 범하고 있다. 북한의 군사지휘체계는 당시 북한이 처한 다양한 상황에서 북한군의 필요한 역할 수행을 강제하기 위한 방향으로 변화하였다. 결국 북한 군사지도·지휘체계는 위협 대응이라는 군사적 필요성 보다 정치적 이유에 우선하여 형성되었으며, 이를 바탕으로 분화와 집중이 이루어져 왔다. 선군시대 역시 당·군관계 변화나 군의 부상에 기인한 것이 아니라, 군에 대한 강력한 통제력을 바탕으로 필요한 역할 수행을 강요하기 위한 군사기구의 기능적 분화가 최고지도자를 중심으로 동질적으로 융합한 것이라 평가할 수 있다. 김일성과 김정일 시기를 거치면서 북한의 군사지도·지휘체계는 최고지도자인 수령을 정점으로 당, 국가, 군이라는 3선으로 분화되어 ① 당 총비서와 당중앙군사위원장의 당적 통제, ② 최고사령관의 작전 지휘 통제, ③ 국방위원장의 군사행정 및 국방경제 통제 영역의 각기 다른 세 가지 계선으로 나뉘어 작동하게 되었다. 김정은 역시 ‘당 제1비서’와 ‘당중앙군사위원장’직을 가지고 중요 군사정책과 군 간부 인사 결정에 관여하고 있으며, ‘국방위원회 제1위원장’직으로 국가 군사기구인 인민무력부, 인민보안부, 국가안전보위부를 지도하고 있다. 또한 군대의 최고직책인 ‘최고사령관’직을 가지고 군대를 직접 지휘 및 지도하고 있는 것이 북한 군사지도·지휘체계의 오늘이다. guidance and command over its military. The launch of Kim Jong Il`s era took place during the period of the Arduous March and the death of Kim Il Sung in 1994. This study seeks to investigate the major changes that transpired over this period in the organizational structure of the Korean People`s Army (KPA) and examine its effect on the current military guidance and command system as Kim Jong Il attempted to consolidate his power in the military. Furthermore, this study attempts to shed light on the changes in military institutions - in its characteristics and relationships between organizations - that surfaced in the course of implementing songun or "military-first" policy and to reveal the realities of the current KPA guidance and command systems through structured and in-depth analysis. The KPA began as a "state`s army"when it was first established but it later transformed into a "party`s army", then to "suryong`s (supreme leader`s) army" after Kim Il Sung began to enforce a direct ruling system from the late-1960s. The KPA solidified its position as the "suryong`s and the successor`s army" long before Kim Il Sung`s death. The KPA began functioning not as the ruling structure for the party but Kim Jong Il`s way of maintaining his regime during the songun era. Through the songun politics, the KPA has become, not the party`s governing system but, the suryong`s personal means to rule the nation. Thus, the KPA`s characteristics began to change, as well as the military guidance and command system, according to domestic politics. Furthermore, the military guidance and command system began to develop into its current distinctive form that corresponded to the current political system of North Korea under the influence of former Soviet Union and China. In other words, the military evolved into a system where its national leader was capable of consolidating his power in the military under the military guidance and command system that supported such rule. Therefore, the military guidance and command system of North Korea may be divided into three parts - the party, military, and state - with suryong in the center that operated in three tiers: (1) General Secretary of the Party and the Party Military Commissioner`s control of the party; (2) the Supreme Commander`s control of the operational command; and (3) the Chairman of the National Defense Commission`s control of the military administration and the defense economy. The military guidance and command system of songun era was a response to short-term crisis management and a product of songun politics. However, it is now reutilized as a principle agent in accomplishing a mid-to-long term goal of becoming a kangsong taeguk or "strong and prosperous nation" and to serve as an important role for direct ruling, establish succession system, and promote regime stability. Consequently, the changes that appeared during Kim Jong Il`s rule was not simply a result of songun politics but acted as a vital link between songun politics and a vision of kangsong taeguk, and for maintaining the Kim Jong Il`s regime. The differentiation and concentration of the guidance and command system that appeared during the songun era can be evaluated as a method to effectively control the military through the process of governing to become a normal state and for the perpetuation of the regime for its leader to remain in power. The logic of equating the stability of regime and perpetuation of regime succession to the stability and future of the party and the state is still being applied even in the current Kim Jong Un`s regime. Currently, Kim Jong Un has earned the titles of first secretary of the Workers` Party and the chairman of the Central Military Commission and has the control over military policy and personnel appointment. He also has the title of the first chairman of the National Defense Commission and directs state organizations such as the Ministry of the People`s Armed Forces, the Ministry of People`s Security and the State Security Department. In addition, he also has direct authority over tlitary as the Supreme Commander, which is the highest position in the military.

A comparative study of dissolving hyaluronic acid microneedles with trehalose and poly(vinyl pyrrolidone) for efficient peptide drug delivery

Kim, Hong Kee,Lee, Soo Hyeon,Lee, Boo Yong,Kim, Sung Jin,Sung, Chang Yub,Jang, Na Keum,Kim, Jung Dong,Jeong, Do Hyeon,Ryu, Hyeon Yeol,Lee, Somin The Royal Society of Chemistry 2018 Biomaterials Science Vol.6 No.10

<P>We studied the role of the additives trehalose and poly(vinyl pyrrolidone) in the physical and pharmacokinetic properties of peptide drug incorporated hyaluronic acid microneedles. Poly(vinyl pyrrolidone) increases the mechanical strength of microneedles and ameliorates drug bioavailability <I>in vivo</I>, suggesting that poly(vinyl pyrrolidone) can be a promising additive in the fabrication of peptide drug-encapsulated fully dissolving microneedles.</P>

Effects of electrochemical oxidation of carbon fibers on interfacial shear strength using a micro-bond method

Dong-Kyu Kim,Kay-Hyeok An,Yun Hyuk Bang,Lee-Ku Kwac,Sang-Yub Oh,Byung-Joo Kim 한국탄소학회 2016 Carbon Letters Vol.19 No.-

In this work, we studied the effects of electrochemical oxidation treatments of carbon fibers (CFs) on interfacial adhesion between CF and epoxy resin with various current densities. The surface morphologies and properties of the CFs before and after electrochemical-oxidation-treatment were characterized using field emission scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and single-fiber contact angle. The mechanical interfacial shear strength of the CFs/epoxy matrix composites was investigated by using a micro-bond method. From the results, electrochemical oxidation treatment introduced oxygen functional groups and increased roughness on the fiber surface. The mechanical interfacial adhesion strength also showed higher values than that of an untreated CF-reinforced composite.

양극산화 처리에 따른 탄소섬유 표면의 페놀릭 하이드록실 관능기 비율의 증가가 에폭시기지 복합재료의 기계적 계면결합 특성에 미치는 영향

김동규 ( Dong-kyu Kim ),김관우 ( Kwan-woo Kim ),한웅 ( Woong Han ),송범근 ( Bhumkeun Song ),오상엽 ( Sang-yub Oh ),방윤혁 ( Yun Hyuk Bang ),김병주 ( Byung-joo Kim ) 한국공업화학회 2016 공업화학 Vol.27 No.5

본 연구에서는 전류밀도 변화에 따른 탄소섬유의 양극산화 처리가 탄소섬유 표면과 탄소섬유 강화 복합재료의 기계적 계면결합력에 미치는 영향을 고찰하였다. 양극산화 처리된 탄소섬유 표면 특성은 원자간력 현미경(Atomic force microscope, AFM)과 전계방사형 주사전자현미경(Field emission-scanning electron microscope, FE-SEM), 적외선 분광법(Fourier transform infrared spectroscopy, FT-IR) 및 X선 광전자 분광법(X-ray Photoelectron Spectroscopy, XPS)으로 분석하였으며, Short beam 전단시험을 통해 표면처리에 따른 탄소섬유 강화 복합재료의 계면 전단강도를 측정하였다. 실험 결과 전류밀도가 증가함에 따라 탄소섬유 표면의 거칠기와 산소관능기의 함량의 증가와, 탄소섬유 강화 복합재료의 층간전단강도(Interlaminar shear strength, ILSS)의 향상 및 페놀릭 하이드록실 그룹과의 비례관계를 확인하였다. CF-2.0 시편의 층간 전단강도는 87.9 MPa로 CF-AS 시편에 비해 약 4% 증가하였는데, 이러한 결과는 양극산화 처리가 산소관능기와 탄소섬유 표면 거칠기의 증가를 유도하여 탄소섬유와 수지의 계면 결합력이 증가된 것으로 판단된다. 그중 층간전단강도와 비례관계인 페놀릭 하이드록실 그룹은 탄소섬유 강화 복합재료의 계면결합력을 향상시키는 중요한 요소라 판단된다. We studied the effects of anodic oxidation treatments of carbon fibers on interfacial adhesion of the carbon fibers-reinforced epoxy matrix composites with various current densities. The surface of treated carbon fibers was characterized by atomic force microscope (AFM), field emission-scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The interlaminar shear strength (ILSS) of the composites was determined by a short beam shear test. This result showed that both the roughness and oxygen group of the carbon fibers surface increased in proportion to the current density. After anodic-oxidation-treated, the ILSS also increased as a function of the current density. In addition, the proportional relationship between ILSS and phenolic hydroxyl group was confirmed. The ILSS of the CF-2.0 sample increased by 4% compared to that of the CF-AS sample, because the anodic oxidation treatment increased the oxygen group and roughness on the carbon fibers surface, which leading to the improvement of the interfacial adhesion of the carbon fibers-reinforced epoxy matrix composites. Among these, the phenolic hydroxyl group which has the proportional relationship with ILSS is found to be the most important factor for improving the interfacial adhesion of the carbon fibers-reinforced epoxy matrix composites.

The Effect of Distal Location of the Volar Short Arm Splint on the Metacarpophalangeal Joint Motion

Joon Yub Kim,Dong Wook Sohn,Ho Youn Park,Jeong Hyun Yoo,Joo Hak Kim,Myung Gon Jung,Jae Ho Cho 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.2

Background: The goals of this study were to compare maximal metacarpophalangeal joint (MCPJ) flexion angles after application of a volar short arm splint at 3 different locations and verify the relations between the three different physical and radiological locations. Methods: Forty dominant hands of healthy subjects were analyzed in the study. We defined a transverse skin folding line as a line drawn from the radial aspect of the thenar crease to the ulnar aspect of the distal transverse palmar crease. The distal end of the volar short arm splint was applied on 3 parallel locations to this line. Location A was on this transverse skin folding line; location B was 1 cm proximal to location A; and location C was 1 cm distal to location A. Two orthopedic surgeons measured the maximal MCPJ flexion angles of each finger except the thumb with the application of a volar short arm splint at 3 different locations as well as without a splint as a control. Radiological locations of the 3 different distal ends of the volar short arm splint were also assessed by anteroposterior radiographs of the wrist. Results: When the splint was applied at location A and C, the maximal MCPJ flexion angle decreased to a mean of 83° (91% of control value) and 56° (62% of control value), respectively (compared to the control, p < 0.001). At location B, the maximal MCPJ flexion angle was a mean of 90° (99% of control value); no significant difference was observed compared to the control or without the splint (p = 0.103). On radiography, the average length from the metacarpal head to the distal end of the splint at all fingers decreased in the order of location B, A, and C (29 mm, 19 mm, and 10 mm, respectively; p < 0.001). Conclusions: We recommend applying the distal end of a volar short arm splint at proximal 1 cm to the transverse skin folding line to preserve MCPJ motion perfectly, which is located at distal 44% of the whole metacarpal bone length radiologically.

미중의 전략경쟁과 중국의 군사적 도전

김동엽 ( Kim Dong Yub ) 한중사회과학학회 2022 한중사회과학연구 Vol.20 No.4

본 연구는 미중의 전략경쟁이 심화되고 있는 상황에서 중국의 군사전략의 변화와 군사력 증강을 고찰해 보았다. 미국의 상대적 쇠퇴 속에 중국의 부상은 미국에게 가장 큰 도전이다. 중국의 일대일로와 미국의 인도태평양전략의 충돌은 밖으로 나오려는 중국과 나오지 못하게 막는 미국 간의 양보할 수 없는 싸움이다. 대만문제와 함께 남중국해에서 군사적으로도 양국의 이익이 첨예하게 대립하고 있다는 점에서 미중 간 군사적 갈등이 격화될 가능성이 높다. 지금까지 미중간의 군사적 갈등은 남중국해와 대만 그리고 일부 동중국해에서 보였던 소규모 함정과 항공기 간의 해상 및 공중에서의 군사적 충돌 양상이 대부분이었다. 그러나 미국이 전방배치를 강화하면서 미중 간 군사적 충돌 지점이 원해로 나가고 있고 충돌의 규모도 커지고 있다. 경제 영역에서 미국의 상대적 약화가 선행되었지만 미중 전략경쟁에 결정적인 영향을 미치는 핵심 변수는 군사적인 문제가 될 수 있다. 군사적 측면에서 중국은 아직 미국에 비할 바가 못 된다. 단기간 내에 중국의 군사력이 미국과 대등해지거나 미국과 중국의 완전한 위치 교환이 이루어 질 가능성이 그렇게 높지 않다. 중국의 군사력이 미국의 군사력을 따라잡는 데는 상당한 시간이 필요할 것으로 보인다. 그러나 현재 미국의 경제가 회복을 한다고 하더라도 중국 경제와의 격차를 유지하거나 다시 벌일 만큼 고속성장을 하기는 어렵다. 미국 연방정부 재정의 한계와 중국 국방예산의 지속적인 증가로 미중 간 군사력의 격차는 점점 줄어들 수밖에 없다는 것이 현실이다. 중국은 중국몽을 실현하기 위하여 강군몽(強軍夢)을 국방정책의 전략 목표로 추진하고 있다. 도련전략의 쟁취를 위해 반접근/지역거부(A2/AD) 수행에 필요한 네크워크화된 무기체계의 Counter-intervention 능력을 극대화해 나가고 있다. 미중의 전략경쟁과 중국의 군사적 도전은 전통적인 지정학적 공간에 한정되지 않고 첨단 과학기술을 기반으로 눈에 보이지 않는 사이버 공간과 우주까지 확장되고 있다. 미중 전략경쟁이 한반도에 어떠한 영향을 미칠 것인지는 정확히 평가하고 대응방안을 모색하기 위해서는 미중 군사관계에 대한 객관적인 이해가 필요하다. This study examined changes in China’s military strategy and military strength in a situation where strategic competition between the U.S. and China is intensifying. Amid the relative decline of the United States, China’s rise is the biggest challenge for the United States. The clash between China’s Belt and Road Initiative and the US’ Indo-Pacific strategy is an irreconcilable battle between China, which is trying to come out, and the US, which prevents it from coming out. Military conflicts between the U.S. and China are likely to intensify, given that the interests of the two countries are sharply divided in the South China Sea along with the Taiwan issue. Until now, most of the military conflicts between the U.S. and China have been seen in the South China Sea, Taiwan, and some East China Seas, both at sea and in the air. However, as the U.S. strengthens its forward deployment, the point of military conflict between the U.S. and China is expanding and the scale of conflict is increasing. Although the U.S. has been relatively weakened in the economic sector first, the key variable that has a decisive impact on the U.S.-China strategic competition can be a military problem. In terms of military, China is not yet comparable to the United States. It is unlikely that China’s military power will equalize with the United States in a short period of time, or that a complete exchange of positions between the United States and China will take place. It will take a considerable amount of time for China’s military to catch up with the U.S. military. However, even if the current U.S. economy recovers, it is difficult to maintain the gap with the Chinese economy or grow rapidly enough to reopen it. The reality is that the gap in military power between the U.S. and China will inevitably narrow due to the limitations of the U.S. federal government’s finances and the continued increase in China’s defense budget. In order to realize the Chinese dream, China is promoting the strong military dream as a strategic goal of its defense policy. In order to complete the Island Chain strategy, the counter-intervention capability of the networkized weapon system required to perform anti-access/region rejection (A2/AD) is being maximized. The U.S.-China strategic competition and China’s military challenges are not limited to space by traditional geopolitics, but are expanding to invisible cyberspace and space based on advanced science and technology. In order to accurately evaluate how the U.S.-China strategic competition will affect the Korean Peninsula and find countermeasures, an objective understanding of U.S.-China military relations is needed.