전장축소형 무화염 소염기 형상설계 연구

김현준,이준호,채제욱,이성배,김인우,Kim, Hyun-Jun,Lee, Joon-Ho,Chae, Je-Wook,Lee, Sung-Bae,Kim, In-Woo 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.6

This paper includes that there are results of designing the flash hider and analyzing fluid dynamics of a front area of the barrel to shorten the length of small arms. Generally, the muzzle flash can be generated out of the barrel by the reaction between the oxygen in the air and unburned gunpowder contained in the propellant gas if a barrel is not long enough to burn gunpowder fully inside of the barrel. Though, the hugh muzzle flash, which is a characteristic of small arms with short barrel length, caused a soldier to aim at the target at night by making the soldier blind for a while and endangers his life by revealing firing position to enemies. Besides, the heat of muzzle flash can weaken the performance of thermal sights, which are attached to small arms for night battlefield. In this paper, flash hiders with several different shapes were designed for a newly developed 5.56mm caliber rifle with short barrel length. The performance of each flash hider to reduce the muzzle flash was compared theoretically and experimentally. Through the authorized test procedure, a highly efficient design of flash hider for reducing the muzzle flash was identified. The result of the paper can be helpful when designing flash hiders for small arms with short barrel length.

물 분자막의 두께와 윤활특성의 상관관계에 대한 분자시뮬레이션 연구

김현준,허세곤,Kim, Hyun-Joon,Heo, Segon 한국트라이볼로지학회 2022 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.38 No.5

This paper presents a numerical investigation of the influence of water molecule thickness on frictional behavior at the nanoscale using molecular dynamics simulation. Three different models, comprising water thin films of various thicknesses, were built, and indentation and sliding simulations were performed using the models. Various normal loads were applied by indenting the Si tip on the water film for the sliding simulation to evaluate the interplay between the water thin film thickness and the normal load. The results of the simulations showed that the friction force generally increased with respect to the normal load and thickness of the water thin film. The friction coefficient varied with respect to the normal load and the water film thickness. The friction coefficient was the smallest under a moderate normal force and increased with decreasing or increasing normal loads. As the water film became thicker, the contact area between the tip and water film became larger. Under well-lubricated conditions, the friction force was proportional to the contact area regardless of the water film thickness. As the normal force increased above a critical condition, the water molecules beneath the Si tip spread out; thus, the film could not provide lubrication. Consequently, the substrate was permanently deformed by direct contact with the Si tip, while the friction force and friction coefficient significantly increased. The results suggest that a thin water film can effectively reduce friction under relatively low normal load and contact pressure conditions. In addition, the contact area between the contacting surfaces dominates the friction force.

솔-젤법을 이용한 aminoalkoxysilane 산소차단필름의 제조

김현준,Kim, Hyun-Joon 한국반도체디스플레이기술학회 2006 반도체디스플레이기술학회지 Vol.5 No.3

The oxygen barrier films were formed on poly(ethylene terephthalate) (PET) substrate by a sol-gel process using aminoalkoxysilanes. The coating layers were characterized by FT-IR and SEM. The oxygen permeability coefficients of coating films were measured by variable volume method, and then the influences of solvent ratio in sol and film drying temperature on the oxygen barrier properties were investigated. The aminoalkoxysilane coating films exhibited much higher oxygen barrier properties than PET film. The oxygen permeability coefficient of the film coated with each of APTEOS and APTMOS was measured to be $2.96{\times}10^{-6}$ and $3.05{\times}10^{-5}\;GPU$, respectively, while that of PET film was $1.16{\times}10^{-4}\;GPU$.

셀롤로오스 분리막을 통한 순수 이산화탄소 메탄 및 혼합기체의 투과 특성 연구

김현준,김홍일,강용수,홍석인 ( Hyun Joon Kim,Hong Il Kim,Yong Soo Kang,Suk In Hong ) 한국공업화학회 1996 공업화학 Vol.7 No.4

Cellulose acetate(CA) 비대칭막, CA 복합막 그리고 cellulose triacetate(CTA) 비대칭막을 통한 순수 이산화탄소 및 메탄의 투과 특성을 측정하여, 투과성능의 운전압력에 대한 영향을 조사하였다. 그리고 이산화탄소와 메탄의 혼합기체(CO ₂/CH₄=57.6/42.4)에 대한 투과 특성을 조사하여, 이를 순수 기체의 투과 특성으로부터 얻어진 결과와 비교하였다. 실험은 25∼125 psig의 분압과 상온에서 실험하였다. CA 복합막과 CTA 막을 통한 기체의 투과거동은 CA 막의 투과거동과 비슷하였다. CA 막, CA 복합막 그리고 CTA 막을 통한 순수 이산화탄소의 투과속도는 상부분압이 증가함에 따라 약간 증가하였으며, 반면에 메탄의 경우에는 상부분압에 의존하지 않고 일정하였다. 그러나 혼합기체의 경우 이산화탄소에 의한 가소화 효과와 각 기체의 경쟁효과에 의해 순수 기체와는 다른 투과거동을 보였다. 각각의 분리막의 투과성능을 비교할 때, CTA 막의 분리인자와 투과속도가 CA 막의 값들보다 높은 값을 나타내었으며, CA 복합막의 투과속도가 CA 막의 값보다 높은 값을 가졌다. 그러나 CTA 막의 경우 기계적 강도가 매우 낮았다. 결국 본 연구에 사용된 CA 복합막이 투과플럭스가 크므로 이산화탄소와 메탄의 분리용 막으로 적합하다고 생각된다. The permeation characteristics were investigated for pure carbon dioxide and methane through asymmetric cellulose acetate(CA) membrane, composite cellulose acetate membrane and asymmetric cellulose triacelate(CTA) membrane. In particular, the effect of operating pressure on the permeation performance was examined. And the permeation behavior for a mixture of carbon dioxide and methane (CO₂/CH₄=57.6/42.4) was also investigated and compared to the characteristics obtained from pure gases. The experiments were run at the range of partial pressure from 25 to 125 psig, and room temperature. The permeation behaviors of the CA composite and CTA membrane were similiar to those of the CA membrane. The permeation rates of pure carbon dioxide for CA, CA composite and CTA membrane were increased slightly with an increase in upstream partial pressure, while in the case of pure methane they were independent of upstream partial pressure. For a binary mixture of carbon dioxide and methane, abnormal permeation behaviors were observed due to the plasticization of carbon dioxide and the competition effect of each gas. The separation factor and permeation rate for CTA membrane were found to be higher than those for CA membrane, but the mechanical strength of CTA membrane was very poor. and the permeation rate for CA composite membrane was higher than that for CA membrane. Consequently, it can be said that the CA composite membrane is a strong candidate for the separation of CH₄and CO₂

[Review] 트라이볼로지 관점에서의 그래핀 분자시뮬레이션 연구동향

김현준(Hyun-Joon Kim),정구현(Koo-Hyun Chung) 한국트라이볼로지학회 2020 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.36 No.2

Recently, graphene has attracted considerable attention owing to its unique electrical, optical, thermal, and mechanical properties. The broad spectrum of applications from optics, sensors, and electronics to biodevice have been proposed based on these properties. In particular, graphene has been proposed as a protective coating layer and solid lubricant for microdevices and nanodevices because of its high mechanical strength, chemical inertness, and low friction characteristics. During the past decade, extensive efforts have been made to explore the tribological characteristics of graphene under various conditions and to expand its applicability. In addition to the experimental approaches, the molecular simulations performed provide fundamental insights into the friction and wear characteristics of graphene resulting from molecular interactions. This work is a review of the studies conducted over the past decade on the tribological characteristics of graphene using molecular simulation. These studies demonstrate the principal mechanisms of the superlubricity of graphene and help clarify the influences of surface conditions on tribological behavior. In particular, the investigation of the effects of the number of layers, strength of adhesion to the substrate, surface roughness, and commensurability provides deeper insights into the tribological characteristics of graphene. These fundamental understandings can help elucidate the feasibility of graphene as a protective coating layer and solid lubricant for microdevices and nanodevices.

분자동역학 시뮬레이션을 이용한 응축된 물분자의 윤활특성연구

김현준(Hyun-Joon Kim) 한국트라이볼로지학회 2022 한국트라이볼로지학회 학술대회 Vol.2022 No.4

독일법상 토양환경보호와 그 시사점

김현준(Kim Hyun-Joon) 한국공법학회 2000 公法硏究 Vol.29 No.1

환경행정법에서의 위험과 리스크

김현준(Hyun-Joon Kim) 행정법이론실무학회 2008 행정법연구 Vol.- No.22

부산의 물리적 환경과 이미지가 외래관광객 관광행동에 미치는 영향

김현준(Kim Hyun-Joon),이상미(Lee Sang-Mi) 한국관광레저학회 2011 관광레저연구 Vol.23 No.2

환경갈등 극복을 위한 환경민주화의 법적 과제

김현준(Hyun-Joon Kim) 한국법학원 2013 저스티스 Vol.- No.134-3

환경갈등이라는 난제는 어떻게 극복할 수 있을까? 다양한 방안들이 그 극복방안의 일환으로 논의될 수 있겠지만, 이들을 포괄하면서도, 구체적 방향설정을 나타내는 핵심목표로서 환경민주화 가 요청된다. 그렇다면, 환경갈등 극복을 위한 환경법의 과제 는 환경법의 민주화 , 즉 환경법 해석론·입법론의 민주화 에 있다고 생각된다. 환경민주주의를 일의적으로 정의하는 것은 쉽지 않지만, 무엇보다 국민 또는 주민과의 의사소통을 바탕으로 환경에 관한 국가나 지방자치단체의 의사를 결정하는 것이라고 할 수 있다. 그 구체적 방안으로서 필자는 ①국가역할의 재정립을 통한 환경민주화, ②절차적 환경권의 정립, ③조정의 활용, 나아가 넓은 의미로는 ④순수 생태이익의 보호의 필요성까지 제시한다. 이들은 무엇보다 현행 환경법률 개별조문의 검토와 함께 이루어져야 할 것이다. 첫째, 환경민주화를 위한 국가의 역할을 우선 정립할 필요가 있다. 이는 국가와 국민간의 관계에 관한 문제라고도 할 수 있다. 시대적 상황이 요구하는 바람직한 국가의 모델로서 보장국가 를 주목한다. 둘째, 헌법 제35조1항의 해석을 통해서도 인정될 수 있는 환경정보액세스권, 환경행정절차참여권, 환경사법액세스권과 같은 절차적 환경권의 실현은 환경민주화와 직결된다. 셋째, 갈등해결의 대표적 기제로 논의되는 조정(mediation)이 우리 법제, 특히 공법관계에서 정착될 수 있도록 해야 한다. 넷째, 특히 넓은 의미의 환경민주주의로서 생태민주주의와 밀접한 관련이 있는 순수 생태이익의 보호 역시 환경민주주의에 기여하는 것이다. 이를 위해서는 사인간의 이익조절의 문제로 해결될 수 없는 영역에서의 책임법제에 대한 인식이 제고되어야 하며, 이에 따른 입법론이 전개되어야 할 것이다. This study examines the environmental conflict between citizens and their government. It focuses especially on legal problems of solving conflict. The meaning of the environmental democracy is debated, but we follow the definition that it is a participatory and ecologically rational form of collective decision making. In order to realize the environmental democratization, this study proposes the following concepts. First, we should clearly establish the new role of a modern state. The model of the “Gewaehrleistungsstaat”, which has been recently asserted in Germany, is worthy of notice. Second, the environmental procedural rights, which contain access to information, public participation in decision-making and access to justice in environmental matters, ought to be accepted in our environmental law scheme. Third, a mediation, in which a neutral third party assists the disputing parties to negotiate a mutually acceptable solution, may play prominent roles in resolving environmental conflict between citizens and the government. In other words, mediation is considered also as a route for resolving public law disputes, particularly in environmental matters. Last, if the environmental democracy is used widely to include the ‘ecological democracy’, legal problems of ecological demage should be also discussed in context of the environmental democracy. Thus such a democracy can be combined with the concept of liability for environmental damage.