가토 간의 VX2 carcinoma : 종양이식방법에 따른 영상소견의 차이 Different Radiologic Features According to Innoculation Methods

이준우,정진욱,최국명,김종재,김세형,최준일,이경호,김승협,박재형 대한초음파의학회 2000 ULTRASONOGRAPHY Vol.19 No.3

펠렛형 제올라이트를 이용한 이산화황의 흡착특성

이재희,김정국,양희철,김준형,이제근 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.1

KA, NaA, CaA 및 NaX 제올라이트가 충전된 실험실 규모의 흡착층을 이용하여 SO_2 유입농도, 충전층 높이 및 공간속도를 변화시키면서 SO_2 흡착실험을 수행하였다. 평형흡착량과 파과시간 모두 제올라이트 세공크기에 따라 KA, NaA, CaA, NaX 순으로 증가하였다. NaX상에서 SO_2를 흡착시킬 경우 SO_2 유입농도 504ppm 이하에서 파과시간은 증가하나 역시 물질전달범위도 증가하여 물질전달 속도는 감소하였다. Wheeler 식으로부터 제올라이트상의 파과시간에 대한 평형흡착량, 공간속도 및 1/C_0의 관계를 확인한 결과, 504ppm 이상보다 504ppm 이하의 저농도에서 파과시간이 상대적으로 증가하였다. The experimental of SO_2 adsorption, with varying SO_2 concentration, packed-bed depth, and space velocity, was carried out using a lab-scale fixed bed with zeolites, such as KA, NaA, CaA and NaX. Both of an equilibrium adsorption capacity and a breakthrough time increased with zeolite pore size, in order of KA, NaA, CaA and NaX. Breakthrough time of NaX increased under SO_2 concentration of 504 ppm, but mass transfer rate decreased due to expansion of mass transfer zone. Breakthrough time is relatively increased in the low gas concentration(<504 ppm) more than high concentration(>504 ppm), which is proved by the effects of equilibrium adsorption capacity, space velocity and l/C_0 for the zeolite from the relationship of Wheeler equation.

전도성 고분자 센서 어레이를 이용한 휘발성 유기 화합물 가스 인식

이경문,주병수,유준부,황하룡,이병수,이덕동,변형기,허증수 한국센서학회 2002 센서학회지 Vol.11 No.5

휘발성 유기 화합물 가스(Volatile Organic Compounds)를 인식하고 분석하기 위하여 전도성 고분자 센서어레이를 이용한 시스템을 제작하였다. Polypyrrole와 Polyaniline을 화학중합법으로 센서에 전도성고분자막을 형성하였고 이를 통해 VOC 검지용 센서 어레이를 제작하였다. 센서어레이로부터 측정되는 다차원 데이터는 주성분분석법(PCA)과 RBF(Radial Basis Function Network)을 이용하였다. 제안된 시스템으로 VOCs 가스를 인식하는데 있어서 RBF Network이 PCA방식보다 더욱 효율적인 것으로 판단되었다. We fabricated gas recognition system using conducting polymer sensor array for recognizing and analyzing VOCs(Volatile Organic Compounds) gases. The polypyrrole and polyaniline thin film sensors which were made by chemical polymerization were employed to detect VOCs. The multi-dimensional sensor signals obtained from the sensor array were analyzed using PCA(principal component analysis) technique and RBF(radial basis function) Network. Throughout the experimental trails, we confirmed that RBF Network is effective than PCA technique in identifying VOCs.

한국·홍콩·싱가폴 호텔기업의 인터넷웹사이트 비교에 관한 연구

이형룡,홍준 세종대학교 관광산업연구소 2002 호텔관광경영연구 Vol.17 No.-

The purpose of this study is to present more effective ways of using the Internet website for hotel industry in Korea. To achieve the goal of this study attempted to compare Internet website of hotel companies among Korea, Hong Kong and Singapore. The structure of this study is as follows. The first chapter shows the background and the purpose of this study, the second chapter deal with literature review on the general concept of the Internet website and the Internet website as a commercial medium. The third chapter describes Information Flow Model on the Internet website. This is framework for the empirical study classified three stages: the one-way communication stage, the interactive communication stage and the transaction stage, the fourth chapter was delineated the method and the results of the empirical investigation and in the final chapter, it was the overall conclusions of this study. According to the result of this study, Korean hotel companies seems to be using the Internet website as a public relation and customer support tool rather than as a sales tool to create for the actual benefit. To improve a function as a sales tool in Korean hotel companies' Internet website suggestions are: First, to sale hotel gift certificates on the Internet website, second, to develop Internet website considered to offer convenience to customer, finally, to make reliable Internet website, which guarantee secure customer information with expansion of security.

非線形 理論에 依한 채터 解析

이형식,정준기,박태형 연세대학교 산업기술연구소 1983 논문집 Vol.15 No.2

The chatter analysis has been studied by many authors using non-linear. In this study, the stability chart obtained from experimental work with a lathe was qualitatively compared with the result of chatter analysis by non-linear theory. Experimental results verify that the stability of the machining process is affected by the width of cut in the following manner. As the chip width is increased from zero with the rotational speed of the workpiece kept constant, three ranges are distinguished; (a) unconditionally stable range, (b) conditionally stable range, (c) unstable range. In the conditionally stable range the system is stable for small disturbances but unstable when these exceed a certain level. When the chatter occurs, the amplitude initially increases and stabilizes itself at a finite level. This phenomenon agrees well with the analysis of non-linear theory qualitatively.

전이성 골종양 환자 1례에 대한 증례보고

이정현,정학수,이은용,김형준 세명대학교 한의학연구소 2001 韓醫學硏究所 論文集 Vol.3 No.-

By process of treatment for a case which diagnosed as metastatic bone tumor and admitted from the 7th March, 2000 to the 7th April, 2000, the results are as follows. Method & Results : This patient was diagnosed as breast cancer metastasizes to bone, was treated with herb medication, acupuncture, moxibustion and kinesio taping. In treatment, cancer pain in lumbar, leg, shoulder, flank and chest portion of the patient was improving. Specially, by moxibustion therapy at pain points, cancer pain was improved remarkably. Conclusion : I consider that cancer pain diseases can be improved remarkably by Acupuncture, Moxibustion therapy.

PGE_2와 DBcAMP가 골조직 세포의 생리적 활성에 미치는 영향

이준기,채한정,강장숙,김형룡 원광대학교 생체재료·매식연구소 1998 원광생체재료·매식 Vol.7 No.2

One of the primary functions for which bones have evolved is to act as structural support. To achieve this goal, bones are remodeling throughout life so that their structure remains optimal for the prevailing mechanical environment. Bone remodeling consists of an initial phase of osteoclastic bone resorption followed by a bone formation period. Prostaglandins are potent regulators of bone formation and bone resorption that can have both stimulatory and inhibitory effects. Elevation of intracellular cAMP is an important intracellular signaling mechanism involved in the regulation of the expression of many proteins. In this study, the author examined whether PGE_2 or DBcAMP affected osteoblastic activation or osteoclastic differentiation in mouse bone marrow cells and osteosarcoma ROS 17/2.8 cells. The effect of PGE_2 and DBcAMP on the cell proliferation was measured by the incorporation of [^3H]-thymidine into DNA. From the result, PGE_2( 0.5-1 ㎍/ml ) and DBcAMP(0.1-0.5 mM) inhibited the [^3H]-thymidine incorporation into DNA. The effect of PGE_2 and DBcAMP on the induction of alkaline phosphatase(ALP) was investigated in ROS 17/2.8 cells cultured in medium containing 0.4% fetal bovine serum. PGE_2 and DBcAMP stimulated ALP activity in the cells. PGE_2 also increased the intracellular cAMPs contents with a maximal effect at 0.5 ㎍/ml. ROS 17/2.8 cells released nitric oxide upon stimulation of PGE2 or DBcAMP with interferon-γ. PGE_2 and DBcAMP increase the phosphorylation level of CREB(cAMP response element binding protein) without any change on the amount of CREB protein. Also, PGE_2 (10^-6 M) and DBcAMP (10^-4 M) significantly increase the generation of osteoclast-like cell in mouse bone marrow cell culture system. In conclusion, the results of this study suggested that PGE_2 and cAMP should appear to be an important regulatory molecule in the processes of bone formation and resorption.

졸 - 겔법에 의한 다공성 알루미나 미분체 제조에 관한 연구 : 2 . 물과 알콕시드의 비가 알루미나 미분체의 결정화 공정에 미치는 영향 2 . The Effect of [ H2O ] / [ Al - alkoxide ]on The Crystallization Mechanism of As - Prepared Particles

이성원,박형상,윤호성,황운연,구기갑,유승준,김용렬,이정운 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.2

알루미늄 알콕시드의 반응속도를 제어하기 위한 혼합용매와 입자제조 과정에서의 응집을 방지하기 위한 분산제로 HPC를 첨가하는 방법에 의하여 구형의 다공성 알루미나 미분체를 제조하였으며, XRD, FT-IR 및 TG-DTA 분석을 통하여 공정변수로 선정한 물과 알루미늄 알콕시드의 비가 제조된 미분체의 결정화 공정에 미치는 영향에 대하여 고찰하였다. 축중합 반응에 첨가된 물과 Al-알콕시드의 비는 제조된 미분체 및 하소 공정을 거친 미분체의 결정구조에 영향을 미침을 알 수 있었다. [H₂O]/[ASB]의 비가 증가할수록 제조된 미분체는 비정질의 Al(OH)₃로부터 점진적으로 AlO(OH)의 화학조성을 갖는 의사-보헤마이트로 결정성이 바뀌었다. 그리고 건조 공정을 거친 미분체의 결정성이 좋을수록 δ와 θ-Al₂O₃는 저온에서 생성되었으나, α-Al₂O₃는 고온에서 생성되었다. 이와 같은 결과는 Al^(3+)이온의 결정 내에서의 배위체 변화와 관계됨을 알 수 있었다. 그리고 [H₂O]/[ASB]=2의 조건에서 제조된 입자는 다른 시료와 달리 600℃에서 η-Al₂O₃로 1,100℃에서 α-Al₂O₃2로 상전이 되었다. Spherical porous alumina particles were prepared by mixed solvent to control the reaction rate of Al-alkoxide and the particle shape with hydroxy-propyl cellulose(HPC). HPC was used as a dispersant to prevent aggregation during the formation of particles. The effect of [H₂O]/[ASB] ratio on the crystallization reactions of as-prepared particles was studied by XRD, FT-IR, and TG-DTA analysis. The mole ratio of water and Al-alkoxide added in the condensation reaction had an important effect on the crystal structure of as-prepared particles and the calcined particles. As the [H₂O]/[ASB] ratio increase, the crystal structure of as-prepared particles was continuously varied from amorphous Al(OH)₃ to pseudo-boehmite with chemical composition of AIO(OH). The samples which have higher crystallinite after drying process were transformed into the δ- and θ-Al₂O₃ at lower calcination temperature, but these sample were transformed into α-Al₂O₃ at higher calcination temperature. This result was thought to be the transformation of the coordination number of Al^(3+) ion in the crystal structure. The particles prepared by [H₂O]/[ASB]=2 condition crystallized to α-Al₂O₃at 600℃ and converted to η-Al₂O₃at 1,100℃ without intermediate phases.

국부 마모 부품을 위한 레이저 표면강화 열처리에 관한 연구

이목영,김형준,김기철,김재웅 한국레이저가공학회 2002 학술발표대회 Vol.2002 No.1

두께 10mn 일반기계구조용강재를 사용하여 레이저 종류에 따른 표면경화 열처리특성에 관하여 알아보았다. 경화층의 형성은 레이저의 종류에 크게 영향을 받았는데, 표면경화 열처리를 위해서는 파장이 짧은 Nd-YAG 레이저를 사용하는 것이 유리하였다. 경화층의 최고경도는 700Hv 가량으로 높게 나타났으며, 레이저 표면경화 열처리는 상온에서 사용되는 부품의 내마모성 향상 특히 국부 마모를 겪는 부품에 효과적일 것으로 판단되었다.

3D-CT를 이용한 골격성 III급 개방교합자의 악교정 수술 전, 후 설골 및 상기도의 변화

이윤섭,백형선,이기준,유형석 대한치과교정학회 2009 대한치과교정학회지 Vol.39 No.2

본 연구는 골격성 III급 개방교합자의 악교정 수술 전, 후 설골과 상기도의 변화를 3D-CT를 이용하여 관찰하고 이를 정상교합자와 비교하기 위하여 시행하였다. 전치부 개방교합을 동반한 골격성 III급 부정교합으로 진단되어 악교정 수술을 받은 환자 중 12명을 선정 후, 3D-CT를 통해 설골과 상기도의 3차원 입체영상을 분석하여, 악교정 수술 전, 후의 설골의 위치 변화 및 상기도의 부피 변화를 살펴보고, 이의 결과를 정상교합자 10명과 비교하였다. 설골은 골격성 III급 개방교합군에서 악교정 수술 전에 정상교합군의 설골에 비해 전방에 위치하고 있었고 악교정 수술 후 설골은 후, 상방으로 변화하였으나 유의성은 관찰되지 않았다. Hyoid plane과 mandibular plane이 이루는 각은 악교정 수술 전의 골격성 III급 개방교합군이 정상교합군보다 큰 값을 나타내었고, 악교정 수술 후에는 그 차이가 더욱 증가하였다. 골격성 III급 개방교합군의 상기도 부피는 정상교합자보다 작으며 이는, 악교정수술 후에 더욱 감소하였다. 3차원 영상 분석 결과, 골격성 III급 개방교합자의 상기도는 정상교합자에 비해 좁으며, 하악골 후퇴술 이후 더욱 감소하기 때문에 이는 수술적 개선의 안정성에 영향을 줄 수 있음을 알 수 있었다. Objective: The purpose of this study was to investigate the structural changes of the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients, and make comparisons with normal occlusion. Methods: Pre- and post-operative computed tomography (CT) examinations were performed on 12 skeletal class III anterior open bite patients who were treated with mandibular setback osteotomy. Using the V-works 4.0 program, 3-dimensional images of the total skull, mandible, hyoid bone, and upper airway were evaluated. Results: In the Class III openbite group, the hyoid bone were all positioned anteriorly, compared to the Normal group (p < 0.05). The angle between the hyoid plane and mandibular plane in the Class III openbite group before surgery was greater than in the Normal group (p < 0.05), and the difference increased after surgery (p < 0.01). In the Class III openbite group, the volume of the upper airway decreased after surgery (p < 0.001) and the volume of the upper airway was smaller than the Normal group before and after surgery (p < 0.001). Conclusions: The narrow upper airway space in skeletal Class III openbite patients decreased after mandibular setback osteotomy. This may affect the post-surgical stability.