Al-Ni계의 기계·화학적 방법으로 제조된 Raney Ni의 미세 구조 분석

최재웅,이창래,강성군,Choi, Jae-Woong,Lee, Chang-Rae,Kang, Sung-Goon 한국재료학회 2003 한국재료학회지 Vol.13 No.1

The Raney Ni catalyst was fabricated by mechanochemically process(MC process) in the Al-Ni system. Intermetallic compound obtained by mechanical alloying was leached in an alkaline solution. The characteristics of the mechanically alloyed powder and Raney Ni catalyst were analyzed by XRD, ICP-AES and EXAFS. In Al-50wt.%Ni, the metastable intermetallic compound phase close to AlNi phase was obtained by mechanical alloying unlike Al-Ni equilibrium phase diagram. The metastable intermetallic compound was transformed into $Al_3$$Ni_2$phase via the annealing at $750^{\circ}C$. The microstructure of Raney Ni fabricated by MC process was mainly bcc Ni including fcc Ni.

내장형 시스템의 동시적 개발을 위한 이산 사건 시스템 형식론 기반 요구사항 평가 방법

최재웅,최창범,Choi, Jae-ung,Choi, Chang-beom 한국시뮬레이션학회 2018 한국시뮬레이션학회 논문지 Vol.27 No.2

최근 정보 통신 기술이 발전함에 따라, 내장형 시스템은 여러 산업 분야에 적용되고 있으며 더욱 복잡해지고 있다. 이로 인해, 내장형 시스템의 개발 비용과 시간도 덩달아 증가하고 있다. 본 논문에서는 내장형 시스템의 개발 비용 및 시간을 절감하기 위해서 내장형 시스템의 동시적 개발을 위한 이산 사건 시스템(DEVS) 형식론에 기반 요구사항 평가 방법을 제안한다. 본 논문에서는 요구사항 명세를 DEVS 원자 모델의 형태로 기술하는 방법을 제안하며, 이를 개발하여 만든 요구사항 모델과 요구사항 평가 대상 시스템을 비교하는 평가자 모델 및 이들을 활용하는 평가 방법을 제안한다. 또한, 요구사항 평가를 위해 만든 요구사항 모델을 내장형 시스템의 동시적 개발 과정에 활용하는 방법을 제안한다. 제안하는 요구사항 평가 방법에 대한 사례 연구로 키넥트 깊이 정보 처리 시스템에 대한 요구사항 평가를 진행하였다. As the technology of information and communication has developed over recent years, an embedded system is applied in multiple industries and becomes more complicated. For this reason, embedded system development cost and time are also increased. For decreasing the cost and time, this paper suggests requirement evaluation method for concurrent development of an embedded system based on Discrete Event System(DEVS) Formalism. This paper proposes a method of describing the requirements specification in the form of DEVS atomic model. Also, the paper proposes the evaluator model that compares evaluation target system and the requirements model that is an implementation of requirement specification and proposes the evaluation method using them. In addition, we propose a method to utilize the requirement model created for requirements evaluation in the concurrent development process of the embedded system. As the case study, this paper proceeds requirement evaluation of Kinect depth data processing system.

기계적 합금화법과 방전 플라즈마 소결법으로 제조된 Al-25Ti-8Mn 금속간 화합물의 산화 거동

최재웅,김기홍,황길호,홍석준,강성군,Choi J. W.,Kim K. H.,Hwang G. H.,Hong S. J.,Kang S. G. 한국재료학회 2005 한국재료학회지 Vol.15 No.7

The oxidation behavior and the thermal stability of nanocrystalline Al-25Ti-8Mn intermetallic compound were investigated. $Al_3Ti$ intermetallic compound, which has a potential for high temperature structural material, was fabricated by mechanical alloying(MA) with $8at.\%$ Mn to enhance the thermal stability and ductility. And Al-25Ti-8Mn intermetallic compound was sintered by spark plasma sintering(SPS) at $700^{\circ}C$. After sintering process, cubic $Ll_2$ structure was maintained without phase transformation and the grain size was about 50nm. To investigate the oxidation behavior of the specimens, thermal gravimetric analysis(TGA) was performed at 700, 800, 900, and $1000^{\circ}C$ for 24 h in $O_2$. As the temperature increased from $700^{\circ}C\;to\;900^{\circ}C$ the weight gain of specimens increased. However at $1000^{\circ}C$, unlike the oxidation behavior of $700^{\circ}C\;to\;900^{\circ}C$, the weight gain of specimen decreased drastically and the transition from linear rate region to parabolic rate region occurred rapidly due to the dense $\alpha-Al_2O_3$.

천연기념물 지정 당산숲·비보숲의 명칭 부여 및 지정 물량 실태 고찰

최재웅,김동엽,Choi, Jai Ung,Kim, Dong Yeob 국립문화재연구원 2010 헤리티지:역사와 과학 Vol.43 No.1

천연기념물의 명칭 부여 및 지정 물량을 포함한 현재의 천연기념물 관련 체계는 일제강점기에 도입된 '조선보물고적명승천연기념물보존령' (1934)을 기반으로 하고 있으며, 이에 따른 골격이 지금까지 그대로 통용되고 있다는 문제점이 지적되고 있다. 당산숲 비보숲은 우리나라 농어촌의 숲문화를 대표하는 전통문화자원이며 국가적 문화자산이다. 천연기념물을 포함한 당산숲 비보숲을 논할 때 천연기념물 등에서 사용하는 "명칭", "분류 체계" 등에 대해서 문화재청에서조차, '조선의임수(朝鮮の林藪)' (1938)라는 일제의 조사보고서에 실린 내용에 전적으로 의존하고 있다는 것이 근본적인 문제점이라고 할 수 있다. 즉, 일제가 1938년에 '완도 예송리 당산숲'을 '례송리상녹수림(禮松里常綠樹林)'이라고 이름을 붙인 후, 현재까지도 우리 농어촌의 당산숲 비보숲을 천연기념물 등으로 지정할 때, 해안가의 경우 대부분 일제가 한 방식대로 '~상록수림'이라는 명칭을 그대로 따르고 있다는 것이 대표적인 예이다. 본 논문의 목적은 천연기념물 제도의 출발점인 일제강점기의 '조선의임수(朝鮮の林藪)' 등 일본 자료에 대한 문제점을 고찰하고, '조선의임수(朝鮮の林藪)' 등의 논리를 우리의 당산숲 비보숲 등에 여과 없이 적용시키고 있는 현 상황을 개선하는 방안을 찾고자 하는 것이다. 이를 위해 천연기념물로 지정된 수림지, 노거수 중에서 당산제를 지내는 당산숲이 있는 18개소를 선정하여 조사, 분석하였다. 결과로서, 천연기념물로 지정된 많은 수림지, 노거수 중에서 그것이 당산숲, 당산나무라면 "~당산숲", "~당산숲과 비보숲", "~당산나무"라는 명칭을 일관성 있게 부여해야 할 필요가 있다는 것을 제안하고자 한다. 이러한 조치가 이루어지면 일제강점기에 도입된 천연기념물 제도의 한계를 극복하는 출발점이 시작될 수 있으며, 우리나라 전통조경 양식 및 문화경관으로서의 당산숲에 대한 위상이 제고될 수 있을 것이다. Currently, the natural monument system of Korea for naming and designation of natural monuments is based on "Chosun Natural Monument Conservation Acts for Treasure, Ancient Landmark, and Natural Beauty" enacted in 1934 during Japanese colonization period. The framework of natural monument system is still in effect, which is pointed out as a problem. The Dangsan forests and Bibo forests are Korean traditional cultural resources representing countryside of Korea. Cultural Heritage Administration follows and relies on the 'Limsu of Chosun' (1938), a report written by a Japanese, for naming and classification of natural monuments. A Dangsan forest at Yesong-ri was named "Yesong-ri evergreen forest" in 1938. They followed the naming system of "evergeen forest" until today. The objective of this study is to review the issues and problems of 'Limsu of Chosun' and natural monument naming system begun during Japanese occupation period, and suggest an alternative to the current situation where naming natural monument accordingly without discretion. Eighteen dangsan forests bibo forests were selected for examination and analysis. The names of the dangsan forests bibo forests were evaluated to find out whether various aspects of the forests are reflected in the name. The study suggests that many forests and old trees designated as natural monument should be named as "~Dangsan forest", "~Dangsan forest Bibo forest", or "~Dangsan tree" with consistency accordingly. The new names will bring a momentum to overcome the limitation of natural monument naming system continued since Japanese occupation period, and also enhance the value of Dangsan forests and Bibo forests as Korean traditional and cultural landscapes.

원주시 성남리 당산숲의 현황 및 경관관리 실태 고찰

최재웅,김동엽,이상화,김성기,Choi, Jai-Ung,Kim, Dong-Yeob,Lee, Sang-Hwa,Kim, Sung-Gi 한국조경학회 2007 韓國造景學會誌 Vol.35 No.3

Rural areas dominate country landscape, where the population is rich in traditional and natural heritage. Dangsan forests and Rural community forests (RCF) have been maintained by local residents for hundreds of years. However, many of these forests have been disturbed, and only small amount of Dangsan forests and the RCF remain due to the efforts of local residents. Recently, the remnants of Dangsan forests and RCF have been regarded as living traditional landscapes representing the cultural and rural background of Korea. But the value of Dangsan forests and the RCFs has not been recognized by many. This study aims to understand the characteristics and management status of Dangsan forests in Sungnam-ri, Wonju. Sungnam-ri has four villages, each of which is bordered by a Dangsan forest at the riparian buffer. Sungnam-ri has been selsected as a site for a rural village development project by the Ministry of Agriculture & Forestry of Korea. Sunghwanglim (the Upper Dangsan forest) is designated as Natural Monument No.93 and entrance is limited in this area. The size of Sunghwanglim is $21,133m^2$, and the major tree species are Kalopanax pictus (Dangsan tree, Divine tree), Pinus densiflora, Abies holophylla, Acer triflorum, Ulmus davidiana, Fraxinus rhynchophylla and Quercus serrata. In total, 124 trees with more than 40 cm in DBH are at this site. As for cultural activities, the Dangsan festival is held on April 8th and September 9th of the lunar calendar at shrines in the forests. Although other Dangsan forests are smaller than Sunghwanglim, they also have similar cultural activities. The landscape of the Dangsan forests have been managed for several hundred years by the local people, and they intend to continue maintaining the Dangsan forests for the purpose of festivals and other cultural activities. The findings in this study suggest that Dangsan forests have the potential for the development of rural villages and for the improvement of cultural and natural landscapes in Korea.

무전해 Ni-B 도금을 이용한 플라즈마 디스플레이 버스 전극용 확산방지막의 열처리 영향

최재웅,황길호,홍석준,강성군,Choi Jae Woong,Hwang Gil Ho,Hong Seok Jun,Kang Sung Goon 한국재료학회 2004 한국재료학회지 Vol.14 No.8

Thin Ni-B films, 1 ${\mu}m$ thick, were electrolessly deposited on Cu bus electrode fabricated by electro deposition. The purpose of these films is to encapsulate Cu electrodes for preventing Cu oxidation and to serve as a diffusion barrier against copper contamination of dielectric layer in AC-plasma display panel. The layers were heat treated at $580^{\circ}C$(baking temperature of dielectric layer) with and without pre-annealing at $300^{\circ}C$($Ni_{3}B$ formation temperature) for 30 minutes. In the layer with pre-annealing, amount of Cu diffusion was lower about 5 times than that in the layer without pre-annealing. The difference of Cu concentration could be attributed to Cu diffusion before $Ni_{3}B$ formation at grain boundaries. However, the diffusion behavior of the layer with pre-annealing was similar to that of the layer without pre-annealing after $Ni_{3}B$ formation. With increasing annealing time, Cu concentration of both layers increased due to grain growth.

무전해 Ni-B 도금을 이용한 플라즈마 디스플레이 버스 전극의 확산 방지막 제조

최재웅,홍석준,이희열,강성군,Choi, Jae-Woong,Hong, Seok-Jun,Lee, Hee-Yeol,Kang, Sung-Goon 한국재료학회 2003 한국재료학회지 Vol.13 No.2

In this study, we have investigated the availability of the electroless Ni-B plating for a diffusion barrier of the bus electrode. The Ni-B layer of 1$\beta$: thick was electroless deposited on the electroplated Cu bus electrode for AC plasma display. The layer was to encapsulate Cu bus electrode to prevent from its oxidation and to serve as a diffusion barrier against Cu contamination of the transparent dielectric layer in AC plasma display. The microstructure of the as-plated barrier layer was made of an amorphous phase and the structure was converted to crystalline at about 30$0^{\circ}C$. The concentration of boron was about 5∼6 wt.% in the electroless Ni-B deposit regardless of DMAB concentration. The electroless Ni-B deposit was coated on the surface of the electroplated Cu bus electrode uniformly. And the electroless Ni-B plating was found to be an appropriate process to form the diffusion barrier.

모델 예측 제어를 활용한 충돌 회피

최재웅,서종상,이경수,Choi, Jaewoong,Seo, Jongsang,Yi, Kyongsu 한국자동차안전학회 2013 자동차안전학회지 Vol.5 No.2

This paper presents collision avoidance using model predictive control algorithm. A model predictive control algorithm determines lateral tire force and yaw moment and steering angle input and differential braking input is determined from lateral tire force and yaw moment. A constraint for model predictive control is designed for obstacle avoidance. A objective function is designed to minimize lateral tire force and yaw moment input and to follow changed lane after collision avoidance. The performance of proposed algorithm has been investigated via computer simulation conducted to vehicle dynamic software CARSIM and Matlab/Simulink.

직선교량에 대한 디지털엔지니어링 모델의 선형연동 프로그램 개발

최재웅,강전용,김현민,Choi, Jae-Woong,Kang, Jeon-Yong,Kim, Hyun-Min 한국BIM학회 2020 KIBIM Magazine Vol.10 No.4

This report describes the development of a program that can be linked to an alignment and extracts related information using a prefab structured digital engineering model. The subject bridge was set as a straight alignment, the Superstructure type as Precast girder and the Substructure type as Precast pier and Cast-in-situ Abutment. We identified the variables required to create a digital engineering model and reviewed them to create the digital engineering model by entering them as numerical values in the program. In addition, it is configured so that the variables linked to the alignment can be entered numerically. The quantity takeoff can be calculated when the design is complete. The purpose of the program development presented in this report is to enable the designers to select the optimal alternative by designing a bridge that best fits their current situation, extracting the relevant information and then by providing it to the manufacturer and construction company.

A1-25Nb계와 (A1,X)-25Nb계 (X = Cr, Cu, Fe, Mn)의 기계적 합금화에 의한 금속간 화합물의 형성 거동에 관한 연구

최재웅,강성군,Choi, Jae-Woong,Kang, Sung-Goon 한국재료학회 2001 한국재료학회지 Vol.11 No.9

In Al-25Nb binary system, it was observed only formation of $D0_{22}$ $Al_3Nb$ intermetallic compound after 5hr milling but it was not observed formation of meta stable phase like L1$_2$ phase. In this state, $D0_{22}$ $Al_3Nb$ fabricated had nano sized grain of approximately 20nm. Ternary systems, transition metals such as Cr, Cu, Fe, Mn were added 6~12at.% as substitution of Al, showed formation of $D0_{22}$ $Al_3Nb$ like Al-25Nb binary system. In Al- l2Cu-25Nb system, it was observed that broad XRD pattern like amorphization of Al and not observed formation of $D0_{22}$ $Al_3Nb$ after 5hr milling. But there was mixed phase of a lot of amorphous Al and little $D0_{22}$ $Al_3Nb$ through TEM. In the states of unalloyed, 5~7hr milling time, those showed exothermic reaction at 35$0^{\circ}C$, which was formation of $D0_{22}$ $Al_3Nb$ like Al-25Nb binary system. With increasing milling time to 10hr, $D0_{22}$ $Al_3Nb$ was transformed to mixed phase of amorphous and nanocryatlline, having approximately 10nm grain but the meta stable $Al_3Nb$ was not fabricated by adding transition metals.