하수준설토와 석분의 건설재료로 재활용을 위한 지반물성연구

정재욱,장연수,Chung, Jae-Wook,Jang, Yeon-Soo 한국지하수토양환경학회 2007 지하수토양환경 Vol.12 No.4

Geotechnical and environmental properties of stone fillers are analyzed by several laboratory experiment to identify the possibility of recycling fillers and sewage dredged soils as construction materials. The result of geotechnjical test shows that the sewage dredged soil is a sandy soil which contains 70-80% sand and is useful as an aggregate of construction site. Stone filler has large fine content, which may disqualifies the use as construction materials. However, this material is still useful as a filler in stone quarries or finished mines. From the environmental test, the liquids leached from two types of materials have satisfied the standard of chemical substances in the soil environment law and no harmful effect in ground pollution is expected when recycling. 본 연구에서는 석분과 하수준설토에 지반물성시험과 토양환경오염 우려기준에 의거한 오염도 측정을 실시하였다. 실험 결과 하수 준설토는 모래가 $70%{\sim}80%$의 비율의 사질계열의 흙으로써 건축 토목공사의 골재재료로써 가치가 크다는 것이 판명되었다. 석분은 세립분의 함량이 큰 관계로 건설재료로 좋은 품질을 보이지는 않았으나 폐광, 석산에서 석재 채취 후 빈 공간 등을 채우는 용도에 적용시킨다면 재활용이 가능한 것으로 나타났다. 유해물질 함유량은 두 시료 모두 토양오염우려기준에 훨씬 못 미치는 수치로서, 재활용시 토양오염에는 거의 영향이 없는 것으로 나타났다.

발사플랫폼의 운용성 확장을 위한 지면기울기 보상기법

정재욱,김룡,Chung, Jae-Wook,Kim, Yong 한국군사과학기술학회 2012 한국군사과학기술학회지 Vol.15 No.1

When missile is launched, a launcher needs to be leveled with accuracy to avoid the systems's instability. In general, a launcher is leveled by adjusting the stroke of leveling jacks; however, it is still challenge to control the leveling jacks fast and accurately. This paper thus proposed an innovative algorithm for compensating ground inclination of a missile launcher to expand operational field of a missile launcher. Using two inclinometers attached on a launcher, a base jack for leveling is selected and the mixed gradient where launcher stands on can be estimated. Due to the limited stroke, the launcher can compensate its ground inclination within maximum stroke margin. Then, the ground inclination of a launcher can be compensated by calculated angle using weighting factors. The effectiveness of proposed algorithm is proved with a prototype missile launcher.

염산티트라싸이클린의 적용시간에 따른 다공성 임프란트 표면 미세구조의 변화

정재욱,허익,권영혁,박준봉,정종혁,Jeong, Jae-Wook,Herr, Yeek,Kwon, Young-Hyuk,Park, Joon-Bong,Chung, Jong-Hyuk 대한치주과학회 2006 Journal of Periodontal & Implant Science Vol.36 No.2

Mechanical and chemical methods are the two ways to treat the implant surfaces. By using mechanical method, it is difficult to eliminate bacteria and by-products from the rough implant surface and it can also cause the structural change to the implant surface. Therefore, chemical method is widely used in order to preserve and detoxicate the implant surface more effectively. The purpose of this study is to evaluate the effect of tetracylcline-hydrochloride(TC-HCI) on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, SLA surface and porous surface were used in this study. Implant surface was rubbed with sponge soaked in 50mg/ml TC-HCI solution for $\frac{1}{2}$ min., 1 min., $1\frac{1}{2}$ min., 2 min., and $2\frac{1}{2}$ min. respectively in the test group and with no treatment in the control group. Then, specimens were processed for scanning electron microscopic observation. 1. Both test and control group showed a few shallow grooves and ridges in pure titanium machined surface implants. There were not significant differences between two groups. 2. In the SLA surfaces, the control specimen showed that the macro roughness was achieved by large-grit sandblasting. Subsequently, the acid-etching process created the micro roughness, which thus was superimposed on the macro roughness. Irrespective of the application time of 50mg/ml TC-HCI solution, in general, test specimens were similar to control. 3. In the porous surfaces, the control specimen showed spherical particles of titanium alloy and its surface have a few shallow ridges. The roughness of surfaces conditioned with tetracycline-HCI was lessened and seen crater-like irregular surfaces relative to the application time. In conclusion, pure titanium machined surfaces and SLA surfaces weren't changed irrespective of the application time of tetracycline-HCI solution. But the porous surfaces conditioned with tetracycline-HCI solution began to be slightly changed from 2 min. This results are expected to be applied to the regenerative procedures for peri-implantitis treatment.

파열식 발사관 덮개의 성능검증을 위한 시험기법

정재욱,신상목,배영관,Chung, Jae-Wook,Shin, Sang-Mok,Bae, Young-Gwan 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.4

When a missile is launched, a fracture-type canister cover should be properly broken by a collision with a missile or inner pressure of a canister. The fracture performance of a canister cover should be evaluated by a test using a real missile; however, it is unrealistic due to high cost and time restriction in a design stage. In this study, a test technique is newly developed to predict fracture performance of a canister cover. The test was design to have same kinetic energy with a real missile test when the cover is collide with a missile. The effectiveness of the suggested test technique was proved by comparing the test result with that of a real missile test.

카먼레일 디젤엔진에서 후분사 변화가 배출가스 성분 및 온도 변화에 미치는 영향에 대한 실험적 연구

정재욱(Jaewook Chung),장동훈(Donghoon Chang),박정규(Jungkyu Park),전광민(Kwangmin Chun) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The post injection effect to enhance aftertreatment devices' performance is essential to meet future stringent emission standards by controlling exhaust gas temperature and emission pollutants. The test has been made with commercial common rail diesel engine by post injection manipulation, to optimize exhaust gas temperature while guarantee low fuel penalty. The optimization was done at 1500,2000 and 2500[rpm] for 2, 4[bar] condition which show low exhaust gas temperature. The main purpose of this test is dedicated to understand mechanism of exhaust gas temperature rise while optimizing.<br/>

로봇 머니퓰레이터용 최적 학습제어기 설계

정재욱(Chae-Wook Chung) 제어로봇시스템학회 2003 제어로봇시스템학회 합동학술대회 논문집 Vol.2003 No.12

地方政府에 대한 理論的 接近과 統合模型設定에 관한 硏究

鄭載旭(Chung Jae-Wook) 한국지방자치학회 1998 韓國地方自治學會報 Vol.10 No.3

FLNN에 기초한 XY Table용 마찰 보상 제어기

정재욱(Chae-Wook Chung),김영호(Young-Ho Kim),국태용(Tae-Yong Kuc) 제어로봇시스템학회 2002 제어·로봇·시스템학회 논문지 Vol.8 No.2

일본의 사회복지체제에 있어서 사회복지서비스에 대한 이용지원체제의 구조와 특징에 관한 연구

정재욱(Chung Jae-Wook) 한국사회복지학회 2005 한국사회복지학 Vol.57 No.1

일본은 근대적 사회복지제도를 도입·운영하기 시작한 이후 자신의 정치사회적 환경과 경제력 등에 기초한 지속적 제도개혁을 통하여 1960~70년대를 전후하여 소위 일본형 사회복지제도를 일단락 지웠다. 당시의 사회복지제도는 조치제도라는 행정처분행위에 기초한 행정기관의 우월적 지위와 복지대상자의 피동성이 전제되었다. 하지만 이와 같은 모습의 사회복지체제와 이용구조는 1990년을 전후하여 근본적 수준의 개혁 요구에 직면하였다. 여기에는 고령사회로의 진입에 따른 복지대상자 중심의 사회복지서비스의 이용구조, 즉 사회복지서비스의 자립지원기능과 이용자본위의 이념이 자리하였다. 이와 같은 흐름 속에서 등장한 것이 사회복지서비스의 이용을 도와주는 이용지원체제이었다. 이용지원체제의 등장은 일본 사회복지체제의 패러다임의 변화로까지 지적된다. 본 글에서는 이용지원체제의 구조적 특징을 확인하는 차원에서 분석모형을 설정하고 이를 준거틀로 하여 기왕에 이용지원기능을 핵심적 역할로 삼고 있는 관련 제도를 살펴보았다. 이를 통하여 확인된 이용지원체제의 구조와 특징으로는 크게 사회복지대상자의 자기실현과 인권보장에 대한 적극적 기여, 사회복지시설 등과 같은 복지공급체제와 내부조직관계의 형성, 사업운영과정에서 있어서의 케어매니지먼트와 케어플랜의 중시, 케어메이저와 같은 전문가 중심의 운영, 이용지원영역의 제한적 개방성(bounded openness)으로 인한 복지공급체제간의 내부거래의 가능성이 나타나고 있다. The purpose of this paper is to analyze the structure and characteristics of the utilization support systems(USS), which has been institutionalized to aid the use of social welfare services in Japan's social welfare systems recently. In order to conduct such purposes, this paper made the process as follows. Firstly, this paper examined the developmental processes of social welfare systems, and the back ground of institutionalization of USS in Japan. Secondly, this paper formulated at ideal dimension the analytic model which was to explain the structure and characteristics of the USS. To build this model, this paper used two factors which were the connective dependency to the welfare support systems and the feasible-satisfying alternative setting for user. Thirdly, this paper analyzed the characteristics of the user-driven support facilities which has already activated in social welfare systems in Japan. According to the result of analyzing such model, this paper explained that USS in Japan has possessed the structure and characteristics, such as to aid self actualization and human right of user, to compose the inner coalition organization with supply systems, to emphasize the employee to train care management's skill, and to keep up bounded openness to USS's participation. Therefore, oligopoly market is formulated owing to bounded openness in the field of USS and the role of social worker such as a care manager is emphasized on making care plan.

GF(p<SUP>m</SUP>)상에서 정의되는 타원곡선을 위한 복합 좌표계 응용

정재욱(Jae wook Chung),심상규(Sang Gyoo Sim),이필중(Pil Joong Lee) 한국정보보호학회 2000 정보보호학회논문지 Vol.10 No.1

타원곡선 이산대수 문제에 기초한 공개키 암호시스템에서 타원곡선 멱승은 반드시 필요한 연산이며 연산들 중에서 가장 복잡도가 크다. 따라서 효율적인 암호시스템 구현을 위해서는 타원곡선 멱승연산을 효율적으로 구현하는 것이 중요하다. 본 논문에서는 복합 좌표계(mixed coordinate system)를 이용한 멱승 방법을 GF(p<SUP>m</SUP>)상에서 정의되는 타원 곡선에 적용하여 최적의 효율성을 갖는 타원곡선 멱승 구현법을 제안한다. 또한 ‘곱셈을 이용한 역원 연산 알고리즘(IM; Inversion with Multiplication)’을 이용하여 더욱 효율적인 구현이 가능함을 보인다. In public key cryptosystems based on elliptic curve (EC) discrete logarithm problem, EC exponentiation is the most fundamental and also the most time-consuming function among EC functions. Thus it is important to implement efficient EC exponentiation to have an efficient EC cryptosystem. In this paper, we propose an efficient EC exponentiation algorithm which is optimized for GF(p<SUP>m</SUP>), by applying mixed coordinate technique. In addition, we show that a more efficient implementation is possible by utilizing `IM (inversion with multiplication), algorithm.