폴리프로필렌 박막에서 비선형 전류 특성에 관한 연구

李準雄 光云大學校 1988 論文集 Vol.17 No.-

In the course of the investigation to the field dependent electrical conduction mechanism in polypropylene, an abnormal conduction phenomena such as voltage controlled negative resistence characteristics has been observed at the junction of two regions characterized by Schottky effect and space charge effect respectively. This abnormal characteristics was observed initially about 110[MV/m] of the field strength and at 25[℃], however, the field strength where it observed was decreased and the apparent feature of negative characteristics was less pronounced as increasing ambient temperature. Although the observations of analogous characteristics in other materials such as polyethylene, polymethylemethacrylate, and polystylene have already been reported together with plausible explanation by Toureille and others, however, it was found that the proposed concept by those authors was little use to the present observations for quantitative discussions. Accordingly we tried to adapt another conceptual discussion based on Gibbons' formulation pertaining to the saturation trend of the field dependent drift velocity of carriers towards the thermal velocity corresponding to the ambient temperature so that the quantitative explanation on the observed facts has been succeeded to same estimate of reasonable acceptance.

絶緣物의 破壞電壓에 對한 考察

李準雄 光云大學校 1974 論文集 Vol.3 No.-

Insulation paper are largely used in the insulation of the electric apparatus. In this experiment have been done on the current and voltage characteristics and the relation between relative humidity and dielectric strength before breakdown occurs. Experimental results slows that diminishing the insulation resistance, increasing tan δand decreasing dielectric strength of paper due to moisture content.

실리콘고무의 유전율과 유전손실에 관한 연구

李準雄 光云大學校 1987 論文集 Vol.16 No.-

The characteristics of the dielectric relaxation in silicone rubbers were studied in the frequency range of 1×10²∼??[Hz] at the temperture range of 30[℃]∼170[℃]. As the results of the study, it has been confirmed that the silicone rubber containing the cross-linking agents of 2.5-bis(tert-butylperoxy)-2.5-dimethyl haxane exhibit the dissipation spectra of two kind[α, βdissipation] due to the siloxane and methyl groups. Particularly, the maximum value of dietectric loss spectra of silicone rubber combing the closs-linking agents of 0.7[phr] to 1.0[phr] are on the increasing in high frequency region, but the specimen of above 1.0[phr] become smaller again. The energy and the entropy of activation on the molicular motion obtained 18.32[cal/mole] and 1.48[cal/mole.deg] in measuring condition respectively.

폴리에틸렌 테레프탈레이트(PET)의 內部摩擦損 및 誘電損의 溫度特性에 關한 相關性 硏究

李準雄,康道烈,金在煥,金鳳洽 光云大學校 1982 論文集 Vol.11 No.-

This paper investigated comparatively the temperature dependence of dielectric α relaxation process and dynamic mechanical α relaxation process. Dynamic mechanical and dielectric loss data on a given polythylene terephthalate (PET) are generally viewed as being directly comparable. This is based on the notion that, if each exhibits a loss peak at about the same temperature and frequency, they must be manifestations of the same process. This supposes that the process couples in the exact same manner with both mechanical and electrical stress fields. That this need be so may be seen from the fact that not only non polar process give rise to dynamic mechanical losses, but also dipolar losses. The results obtained are as follows. 1) Dielectric α peak and dynamic mechanical α peck in PET are observed at almost same temperature correspondently. 2) The elongated sample exhibits the higher α peck at the almost same maximum temperature. 3) The magnitude, location and breadth of the α relaxation in PET are strong function of the degree of crystallinity and also the manner in which a particular degree of crystallinity is attained. And the degree of crystallinity is changed with external conditions, that is, density, annealing. quenching, drawing, orientations and irradiation etc. 4) In the results of observation the absorption peak at 1,788 ?? on infrared spectra, the more bigger concentration of carbonyl dipole group was observed on the elongated sample.

저밀도 폴리에틸렌에 불포화분자의 그라프트 반응

강웅일,선우창신,서호준 전남대학교 촉매연구소 2001 觸媒硏究 論文集 Vol.22 No.-

The functionalization of low density polyethylene with MAH (maleic anhydride), DEF (diethyl fumarate), DBM (dibutyl maleate) and MMA (methyl methacrylate) as a polar functional monomer and DCPO (dicumyl peroxide), BPO (benzoyl peroxide) as radical initiator was investigated. The grafting was conducted under different operating conditions to investigate the effects of various factors, such as unsaturated molecules concentration, initiator concentration, reaction temperature, reaction time. Also in order to investigated degree of functionalization, the grafted polyethylene wax characterized by FT-IR. DSC and SEM. The results of FT-IR spectra showed the grafting polymers analyzed a C=O absorbance band. A melting temperature and heat of fusion were confirmed by DSC. The optimal grafting yield was obtained at an unsaturated molecules concentration, 5g, initiator concentration, 0.8g reaction temperature, 140℃, reaction time, 3h. The grafting yield of the unsaturated molecules was as follow using DCPO; MAH>DEF>DBM>MMA and the grafting yield of the unsaturated molecules was follow using BPO; MAH>DEF>DBM=MMA and DCPO was found to be an excellent initiator for a grafting reaction.

폴리플로필렌 일렉트렛트의 熱剌激電流

李準雄 光云大學校 1984 論文集 Vol.13 No.-

온도 범위 293°K∼403°K 사이에서 폴리플로 필렌필름의 熱刺激電流特性을 연구하였는데 366°K에서 나타난 β피크는 "CO"극성기의 기여로 생기는 것 같고 初期上昇法으로 구한 이 피크의 活性化에너지는 0.6∼0.7[eV]를 얻었다. 또 初期케리어의 密度는 約 10?/㎥이였다. Studies has been carried out on the characteristics of thermally stimulated current for Polypropylene in the temperature range from 293°K to 403°K. The main Peak observed at 366°K, as may be β peak in conventional nomination, is believed to be depolarization current originated from the relaxation of "CO" base in monomer structure. The activation energy for the observed peak has been concluded to be in the range of 0.6∼0.7(eV) at 360°K by the initial rise method. Furthermore, the initial density of carriers were calculated about 10?/㎥.

高分子誘電體에 對한 硏究

李準雄 광운대학교 1972 論文集 Vol.2 No.-

高分子 材料의 誘電特性을 살핌에 있어 Debye의 理論式을 실험사실과 一致하도록 修正된 Cole Cole式에 立脚하여 分散周波數上下에 單一雙極子가 參與하는 경우에 적용될 수 있는 特性式을 參考하였고 二系 또는 그 以上의 雙極子가 參與하는 혼성分散의 可能性을 살피기 위해 擴大된 特性式을 誘導하였다. 結果로서 單一雙極子만이 參與하는 경우는 드물고 二系 또는 그 以上의 雙極子가 參與하는 혼성分散이 나타남을 確認하였다. For the investigation of dielectric characteristics in polymerized materials, this paper based on the Cole-Cole formula being adapted the Debye's theory for experimental facts in this field and equations derived from it were referred, which may be useful in the range far from the dispersive frequency of samples for the case associated by a sort of dipole in the dielectric phenomenon. Also a set of new equations have been derived to check the possibility of the hybrid dispersion associated by two on many sorts of dipoles in the materials. As the results of the study, it is confirmed that the case of dispersion associated by a sort of dipole is rare and, in general, the case of hybrid dispersion associated by two or many sorts of dipoles are common.

산업대학 건축공학과 교육과정 개발에 관한 연구

임응찬,한인웅,이승준,박재호,조방현,서형수,정구용,한기원,김진원,임상규,이재윤 三陟大學校 1996 論文集 Vol.29 No.2

By impproving the educational program of the Department of Architectural Engineering and studying the theory of learning and the applied method necessary for the development of nation and society, we should develop a satisfying course of education to meet the demand and skill in the industralized society for the purpose of cultivating men of baility with great personalities and creative minds. Therefore, this study focused on classifying several kinds of occupations in the prart of architectured related to what graduates from the department of Architectural Engineering go with into the society. Accordingly after choosing some works adequate to each occupation by the proposed curricula, we tried to establish the scope of education and courses corresponding to the jobs and thus and develop a satisfying curriculum.

低密度 폴리에틸렌 일렉트렛트의 熱刺 激電流 解析에 關한 硏究

李準雄 光云大學校 1983 論文集 Vol.12 No.-

The thermostimulated discharge currents of low-density polyethylene electrets were measured versus the principal experimental variables. Several electrode types were used for the charging and discharging procedures. The results led to know the experimental conditions for the hetero-charge and homocharge accumulating and decreasing. The electronic structure parameters of polyethylene such as trap level, density of traps, hopping length, mobility, trap time constants were deduced. A method for evaluating the local electric field inside the electret is proposed.

전력 송·배전 시스템 상에서 발생하는 이벤트에 대한 데이터 마이닝 가상 트랜잭션과 연관 규칙의 적용

이준섭,이창언,윤상일,김응모 成均館大學校 科學技術硏究所 2002 論文集 Vol.53 No.1

There has been much research on data mining techniques for applying more advanced applications. In this paper, we introduce a approach to convert time series data into virtual transaction data for analysis power electronic transmission and distribution system. However, most of these techniques has focused on transaction data rather than time series data. We present a new way which is discovered and repaired faults of Electric Power system using Data Mining techniques.