플라스틱광섬유섬광체를 이용한 방사선계측에 관한 연구

홍상범,김계홍,박재우 제주대학교 방사능이용연구소 2002 연구보고 Vol.16 No.-

We have used plastic scintillating fibers to detect gamma rays emitted from ^137Cs, and beta rays from ^90Sr. The sensors are constructed of single-stand or multi-strand fibers of 1㎜ and 0.5㎜ diameters. The plastic scintillating fibers used are in commercially available Bicron model BCF-12 fibers with the cladding made of PMMA (polymethyl methacrylate). We used a mirror and lens to improve the effeciency of the sensor with collecting multi-strand plastic scintillating fober. In this paper, we report the pulse-height spectra obtained by using these sensors, and analyze them in the aspect of their usability for radiation detectors. Our investigation suggests that the plastic fiber sensor work satisfactorily for the gamma ray detection, but does not work for the beta ray detection. In effect, We find the scintillating plastic fiber offers some feasibility as gamma ray sensor material.

임플란트 주위 조직 보존을 위한 임플란트 경부의 디자인에 관한 고찰

김홍준,김지환,김성태,이재훈,박영범 大韓齒科保存學會 2011 Restorative Dentistry & Endodontics Vol.36 No.6

연구 목적: 임플란트 식립 후 변연골 흡수에 따라 임플란트 주위 연조직이 재구성되며, 이에 따라 치료의 예후 및 심미성 등에 영향을 주게 된다. 그러므로 임플란트 경부 주위 골조직 보존을 위한 임플란트 경부에 다양한 디자인이 연구되고 있다. 본 고찰의 목적은 초기 변연골 흡수의 원인과 이에 따른 임플란트 주위의 연조직 변화에 대해 고찰하고, 어떠한 임플란트 경부 디자인이 임플란트 주위 조직의 보존에 유리한 지 알아보고자 한다. 연구 재료 및 방법: Pubmed database에서 임플란트 초기 변연골 흡수의 원인과 관련된 논문과 임플란트 경부의 여러 디자인에 관한 논문을 검색하여 분석하였다. 임플란트 경부 디자인은 one piece implant, two piece implant, internal hex abutment, external hex abutment, taper joint connection, butt joint connection, scalloped design abutment, platform switching concept에 관해 검토하였다. 결과: 초기의 임플란트 주위 조직 보존에 대하여 one piece implant가 two piece implant보다 유리한 것으로 여러 임상적, 실험적 연구가 있다. Two piece implant에서는 internal hex abutment가 external hex abutment보다, taper joint connection가 butt joint connection보다 유리할 것으로 보여진다. Scalloped design abutment에 대해서는 논쟁의 여지가 있어 더 많은 연구가 필요할 것으로 판단된다. Platform switching concept은 그 원인이 명확히 밝혀지지는 않았으나 임상적, 실험적으로 초기 임플란트 주위 조직 보존에 대해 유리한 것으로 판단된다. 결론: 임플란트 경부의 디자인마다 각각의 장단점이 있고 추가적인 연구가 더 필요한 제한이 있지만 현재까지의 선행 연구들을 분석 종합해 보면 초기 임플란트 주위 조직 보존을 고려한다면 가능한 경우 one piece implant가 유리할 것으로 판단되며, 보철적인 문제나 다른 이유로 인하여 two piece implant를 고려할 경우 platform switching concept, internal connection abutment, taper joint connection을 이용하는 것이 임플란트 주위 조직 보존에 좀더 유리할 것으로 사료된다 Purpose: The peri-implant soft tissue is remodeled by the initial marginal bone resorption affecting the prognosis and esthetic result of treatment. Thus various designs on implant neck design are studied to preserve peri-implant bone. The purpose of this study is to review on the causes of initial marginal bone resorption, the configuration of peri-implant soft tissue, and the implant crestal module favorable in preserving peri-implant tissue. Materials and methods: The studies on the causes of initial marginal bone resorption and the implant crestal modules are researched and reviewed using Pubmed database. The implant crestal modules including one piece and two-piece implant, internal and external hex abutment, taper and butt joint connection, scalloped design abutment, and platform switching concept are reviewed. Results: A number of clinical and experimental studies preferred one piece implant to two-piece in preserving initial peri-implant tissue. For two piece implants, internal hex abutment and taper joint connection appear more favorable than external hex abutment and butt joint connection relatively. Controversial issues still exist on scalloped design requiring more studies on it. Although the rationale is not certain, the concept of platform switching seems favorable in preserving initial peri-implant tissue based on clinical and experimental studies. Conclusion: Each implant crestal module contains its own advantages and disadvantages with various controversial issues. In the aspect of preservation of initial peri-implant tissue, however, one-piece implant seems beneficial. In cases when two-piece implant is more appropriate due to prosthodontic concerns or any other problems, the application of platform switching concept, internal connection abutment, and taper joint connection may be favorable for the preservation of peri-implant tissues.

수정된 델타 변조를 이용한 Convolver

홍기범,최성률 호남대학교 산업기술연구소 1998 산업기술연구논문집 Vol.6 No.-

본 논문은 MDM(Modified Delta Modulation)을 이용하여 convolution을 행하는 것에 대한 연구이다. 일반적으로 convolution을 수행하면 data 수(N)의 제곱인 N²만큼의 multiplier가 필요하나 본 방법을 사용하면 2N-1개의 multiplier만 필요하게 된다. DM(Delta Modulation)을 이용한 convolution에서는 부호 및 데이터의 유무를 나타내는 register(L)가 2 bit 이었으나 MDM의 경우는 약 6 bit 가 필요하다. 그러나 MDM방법에 의한 convolution을 수행하는데 필요한 sampling rate는 DM의 경우에 비해 낮아도 된다. 따라서 계산해야할 데이터 수(N)가 감소한다. In this paper, convolution for MDM encoede signal is considered. If we use this method, we need only 2N-1 multipliers-noe multiplier for each n-for convolution, the number of which is same as the number of multipliers for convolution for DM encoded signal. The other components are adders and digital logics. So calculation speed for convolution by this algorithm could be very fast. For convolution using DM method, 2 bit register L, which has information of sign and existence of data, is meeded, for MDM 6 bit register is required, but sampling rate could be lower. So the number of data,N,to be calculated could be reduced.

低溫電力電子

홍기범,최성률 호남대학교 산업기술연구소 1997 산업기술연구논문집 Vol.5 No.-

본 논문은 저온에서 동작하는 전력전자회로의 필요성과 가능성을 고찰하였으며, 자료수집 및 실험을 통하여 전력전자회로를 구성하는 주요소자의 저온 특성에 대하여 고찰함으로써 저온 전력 전자용 소자 선택의 길잡이로 사용할 수 있도록 하였다. In this paper, discussions about the needs and possibilities of power electronic circuits operating at low temperatures was presented. And low temperature characteristics of power electronic devices, which were given by experimental work and this paper can be used as the guide for choosing power electronic devices, which would operate at low temperatures.

요추지주막하-복강 단락관의 자발성 골절 - 증례 보고 -

이성주,심기범,김하영,홍승관 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.1

원료탄의 배합비율에 의한 활성탄의 기능성 향상

홍인권,김상철,김원일,이승범 단국대학교 1998 論文集 Vol.33 No.-

Adsorption characteristics of activated carbon were affected by raw materials and operating conditions. Coal based activated carbons were prepared in a rotary kiln type furnace and the pretreatment effect of raw materials for preparing activated carbon was investigated. Steam was employed in manufacturing process as an activation agent. Activation temperature affected the properties of activated carbon. The adsorption capacity, or iodine value was increased in te activation temperature range of 800 to 900℃, yet decreased at higher temperatures than 900℃. Then, the activation effect was analyzed in terms of the activated carbon(AC) yield. It was found that the optimum heating rate and steam amount were 2.9℃/min, and 1g steam/g coalㆍhr, respectively. Effect of coal blends on the preparation of activated carbon was examined. The developing patterns of pore structure were varied with mixing ratio. As the amount of anthracite coal was increased, AC yield increased but adsorption capacity decreased. Pore size and pore size distribution were examined by BET specific surface area analyzer. In the AC yield range of 30∼40%, prepared activated carbon has micropores of sizes below 30Å and iodine value was above 1,000㎡/g in the temperature range of 850∼900℃. Benzene adsorption capacity was similar to those of mixed and Fushun coal but MEK adsorption capacity was superior to that of functions mixed coal. We found that the activated carbon based on coal has comparable to those of commericial products.

메탄올 용매 중에서 벤젠술포닐클로라이드의 가아민분해반응에 대한 속도론적 연구

홍성완,정순량,오해범 우석대학교 부설 기초과학연구소 1997 기초과학연구소 논문집 Vol.2 No.-

Kinetic studies of nucleophilic substitution reactions of substituted benzenesulfonyl chlorides with substituted N,N-dimethylanilines were conducted at 35.0℃ in methanol. Results showed that (ⅰ) the magnitude of ρ_X and β_X associated with a change of substitutent in the nucleophile are large and indicate a relatively advanced bond-formation in the transition state, (ⅱ) The large negative cross-interaction constant. ρ_(XY) = -0.53. These values show that aminolysis of benzenesulfonyl chlorides proceeds by S_N2 mechanism with some S_N2 -S_AN border reaction.

연구로 1,2호기 해체 금속폐기물의 재활용에 따른 피폭방사선량 평가에 관한 연구

홍상범,정운수,박재우 제주대학교 방사능이용연구소 2003 연구보고 Vol.17 No.-

The exposure dose of recycling and reuse on a large amount of the steel scrap from the KRR-1 & 2 decommissioning activities was evaluated. The maximum individual dose and collective dose were evaluated by using international technical criterion and recommendation for NUREG-1640 and IAEA Safety Series 111-P-1.1 and modifying internal dose conversion factor which was based on the concept of effective dose in ICRP 60, applied to the RESRAD-RECYCLE(Ver. 3.06) computing code as the assessment tool. The exposure does were ultimately determined by extracting the most conservative value from the results of the generic assessment and specific assessment methodologies. The result of assessment for individual dose and collective dose is 23.9 μ㏜ per year and 0.11 man ·㏜ per year respectively. The result of clearance level for radionuclides(Co^(60), Cs^(137)) is less than 0.167 Bq/g to comply with the clearance criterion provided for Korea Atomic Energy Act and relevant regulations.

중소기업 신용평가 모형구축에 관한 연구 : 중소기업 신용평가표를 중심으로

洪在範,李相奭 강남대학교 사회과학연구소 1998 사회과학논총 Vol.5 No.-

Acetonitrile-Methyl alcohol 혼합용매중에서 β-phenylethyl ρ-chlorobenzenesulfonate와 Aniline과의 반응속도 연구

홍성완,오해범,한광래 又石大學校 1985 論文集 Vol.7 No.-

The reactions of β-phenylethyl p-chlorobenzene sulfonate with aniline have been studied in acetonitrile-methyl alcohol by conductometric method. The temperature of reaction were 45℃, 50℃, 55℃ and the activation thermodynamic parameters were evaluated. In results, the rates of reaction were increased with MeOH content. The isokinetic relationship was shown ΔH^≠ and ΔS^≠ its temperature was 293.1°K It was also found that the specific solvent effects were more important than the bulky solvent effect in the rate of reaction.