유동화 재순환 반응기에서 석유의 수소첨가 반응시 이탈된 온도제어

이창우,홍영호,함영민 한국산업안전학회 1998 한국안전학회지 Vol.13 No.2

This study was carried out to investigate the effect of on temperature control from actuating method, recycling ratio and the position (top, middle and bottom) of set and controlled temperature within the reactor in adiabatic ebullated recycling condition, when the disturbance was occured. Estimation of the solution were performed numerically using the finite difference method. It was assumed that the reaction is in constant with heat of reaction and the physical properties (density, heat capacity and viscosity, etc) of the reactants are same condition within the reactor.

A Model for Computer-Aided Process Planning System in Flexible Manufacturing Systems

Kang, Young-Sig,Hahm, Hyo-Joon,Rim, Suk-Chul,Kim, Seung-Baum The Korean Society for Quality Management 1994 품질경영학회지 Vol.22 No.1

Most of computer-aided process planning(CAPP) systems have been developed to automate the process planning function. In this paper, we describe an analytical model for a CAPP system in order to improve the performance of production system in flexible manufacturing systems(FMSs) for computer intergrated manufacturing(CIM) architecture. This paper proposes an optimal process planning that minimizes the load time by minimizing the cycle time and the number of workstations using Kang and Hahm's heuristic approach so as to improve the performance of production system under the batch production of discrete products. We also perform simulation using SIMAN language to campare the line utilization of each for various product types. The proposed algorithm can be implemented in existing FMSs for on-line control of product quantity using programmable logic controllers(PLC) and communication devices.

한국과 일본 대학생의 스포츠상황에 대한 도덕적 가치판단수준 비교

함정혜(Chung Hae Hahm) 한국여성체육학회 2013 한국여성체육학회지 Vol.27 No.1

The purpose of this study was to compare the differences of moral reasoning among general students, sports related majors students, and student athletes in Korea and Japan University. We collected total 612 out of 700 (315 from Korea, 297 from Japan) and 88 questionnaires were excluded questionnaire due to incompleteness and unreliable data. For this study, Hahm-Bellar Values Choice Inventory-16(HBVCI-16), which is a Moral Reasoning Questionnaire on Sports Activities, was used. The collected data was analyzed by t-test, one way ANOVA and two way ANOVA with using SPSS Var. 17.0 statistical package program and result were as follow. First, the Japan student`s overall score of moral reasoning were lower compare to Korean university students. Second, there were 1 % higher score of moral reasoning in woman against man and in younger subjects. Sports majored university students presented 1% higher score against other related students and higher grade students presented 5% higher score against lower grade students. Third, among student athletes of Korea and Japan, although there were no significant differences, it was 0.1% higher among those who engaged in individual sports and 5% higher score in those who have less sports career.

Photo‐ and Rubbing‐Alignable Brush Polyimides Bearing Three Different Chromophores

Hahm, S. G.,Lee, T. J.,Ree, M. WILEY‐VCH Verlag 2007 Advanced Functional Materials Vol.17 No.8

<P><B>Abstract</B></P><P>Three new photoreactive brush polyimides (PSPIs), each bearing a different type of chromophore (cinnamoyl (CA), 3‐(2‐furyl)acryloyl (FA), and methacryloyl (MA)) in their bristles (i.e., side groups), are successfully synthesized, and are found to produce good‐quality films with smooth surfaces through conventional spin‐casting and drying processes. These PSPI polymers are thermally stable up to 320 °C. This is the first quantitative investigation of the photoaligning and rubbing‐aligning processabilities of PSPI polymer films, and of the abilities of the resultant films to control the orientation and anchoring of liquid‐crystal (LC) molecules. The chromophores of both poly(1‐cinnamoyloxy‐2,4‐phenylene hexafluoroisopropylidenediphthalimide) (6F‐DAP‐CA) and poly(1‐3‐(2‐furyl)acryloyloxy‐2,4‐phenylene hexafluoroisopropylidenediphthalimide) (6F‐DAP‐FA) PSPIs are found to undergo photodimerization in thin films and, to a lesser extent, photoisomerization, resulting in insoluble, crosslinked films. The MA chromophores of 6F‐DAP‐MA PSPI are found to undergo photopolymerization in thin films, which might include photodimerization to a lesser extent, resulting in insoluble, crosslinked films. Thin films of the PSPI polymer chains are found to have excellent unidirectional orientation ability as a result of either photoexposure with linearly polarized UV light (LPUVL) or rubbing. Both the photoaligned and the rubbing‐aligned polymer chains in the PSPI films are demonstrated to effectively induce the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The contribution to LC alignment of the microgrooves developed in the rubbed films is found to be very low. The anchoring energies of the LCs on the photoaligned film surfaces are comparable to those on the rubbing‐aligned film surfaces; the anchoring energies are found to be in the range 0.45–2.25 × 10<SUP>–5</SUP> J m<SUP>–2</SUP>, and to depend on which film treatment process is used and which chromophore bristle is present. In summary, the new PSPIs reported in this paper are promising LC alignment‐layer candidates with rubbing‐free processing for the production of advanced LC‐display (LCD) devices, including LCD televisions with large display areas.</P>

Pattern and factors leading to the diffusion of magnetic resonance imaging in Korean hospitals

Hahm, Myung-Il,Park, Eun-Cheol,Lee, Sun-Hee,Nam, Chung Mo,Kang, Hye-Young,Lee, Hoo-Yeon,Cho, Woo-Hyun Cambridge University Press 2007 International journal of technology assessment in Vol.23 No.2

<P>Objectives: The purpose of this study was to examine the diffusion patterns of new medical technologies in Korean hospitals. We also sought to identify critical factors leading to the decision to acquire capital-intensive medical technology. The rationale and timing of magnetic resonance imaging (MRI) acquisitions were retrospectively evaluated according to a “whether, when, and why” paradigm.</P><P>Methods: We analyzed data pertaining to 232 hospitals with active medical residency programs. Of these, 185 hospitals owned or leased an MRI unit, and 47 had not acquired units as of June 2004. Data were collected from the Ministry of Health and Welfare, Korean National Statistical Office, and Korean Hospital Association databases, and variables were identified and classified as predisposing, enabling, or reinforcing factors.</P><P>Results: The MRI diffusion rate curve was linear for two types of hospital but was S-shaped for tertiary hospitals, which were early adopters of MRI. Significant predictors for MRI adoption included the per capita number of regional physicians (+), total number of existing regional MRI units (−), percentage of the regional population over 65 years of age (+), private ownership of the hospital, presence of a radiology residency program, number of beds (+), and regional per capita taxable income (+).</P><P>Conclusions: Diffusion of MRI technology is occurring rapidly across Korean hospitals. The factors affecting MRI adoption in Korea are similar to the factors documented in other countries, namely regional population over age 65, regional income per capita, large hospitals, and teaching hospitals. This study provides baseline information for predicting diffusion patterns of other new and/or expensive medical technologies.</P>

A Remote Educational System in Medicine using Digital Video

Hahm, J. S.,Lee, H. L.,Kim, S. I.,Shimizu, S.,Choi, H. S.,Ko, Y.,Lee, K. G.,Kim, T. E.,Yun, J. W.,Park, Y. J. G. Thieme 2007 Hepato-gastroenterology Vol.54 No.74

Trellis-coded 16-QAM with base station antenna switching in slow Rayleigh fading channel

Hahm, Young Kwon 대한전자공학회 1996 APCCAS:Asia Pacific Conference on Circuits And Sys Vol.1 No.1

The existing coders used in the fading channels are designed under the assumption that the ideal interleaver , which removes the fading correlation of the channel, is used. With the non-ideal interleaver of finite size, however, the performance of the coded modulation system degrades rapidly when the fading is very slow. So author propose a scheme to get inerleaving effects by switching base station antennas in a forward link, without additional software or hardware in small handset. We derive the theoretical upper bound on the pairwise error probability and do computer simulations for BER performance. The results show significant performance improvement in the slow fading and at least no deterioration in the fast fading over the existing systems.

Electrical Memory Characteristics of Nitrogen-Linked Poly(2,7-carbazole)s

Hahm, Suk Gyu,Lee, Taek Joon,Kim, Dong Min,Kwon, Wonsang,Ko, Yong-Gi,Michinobu, Tsuyoshi,Ree, Moonhor American Chemical Society 2011 The Journal of Physical Chemistry Part C Vol. No.

<P>We studied the electrical memory characteristics of the following nitrogen-linked poly(2,7-carbazole)s: poly(9-hexadecyl-2,7-carbazole-<I>alt</I>-<I>N</I>,<I>N</I>-(4-hexadecyloxy)aniline), poly(9-hexadecyl-<I>N</I>,<I>N′</I>-diphenylcarbazole-2,7-diamine-<I>alt</I>-1,3-benzene), and poly(9-hexadecyl-<I>N</I>,<I>N′</I>-diphenylcarbazole-2,7-diamine-<I>alt</I>-4,4<I>′</I>-biphenyl). These polymers are amorphous; however, in thin films, they are slightly oriented in the film plane. All polymers in devices with aluminum top and bottom electrodes were found to exhibit similar dynamic random access memory (DRAM) behaviors without polarity. They are operable with a low voltage (less than ±3 V) and a high ON/OFF current ratio (10<SUP>5</SUP>–10<SUP>9</SUP>, depending on the polymer) over the thickness range 8–60 nm. The memory behaviors were found to be governed by space-charge limited conduction and local filament formation. These memory characteristics might originate from the electron-donating carbazole and triphenylamino units in the polymer backbones, which act as charge-trapping sites but have weak electric polarization because of the absence of counterparts. Overall, these polymers are suitable active materials for the mass production at low cost of high-performance, programmable volatile memory devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2011/jpccck.2011.115.issue-44/jp207211e/production/images/medium/jp-2011-07211e_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp207211e'>ACS Electronic Supporting Info</A></P>

Personal background and cognitive factors as predictors of the intention to be screened for stomach cancer.

Hahm, Myung-Il,Choi, Kui Son,Park, Eun-Cheol,Kwak, Min-Son,Lee, Hoo-Yeon,Hwang, Seung Sik American Association for Cancer Research 2008 Cancer Epidemiology, Biomarkers & Prevention Vol.17 No.9

<P>Although stomach cancer screening is effective for reducing mortality, it is underutilized in Korea. By applying an extended theory of planned behavior model, our objective was to determine how personal background factors influence a patient's inclination to be screened for stomach cancer. The study population was derived from the 2006 Korean National Cancer Screening Survey, which was done to investigate the participation of the general population in cancer screening. In total, 1,509 Koreans who were 40 to 70 years old participated in this study. Path analysis was used to test a conceptual model in which (a) factors considered as precursors to be screened (components in theory of planned behavior model) directly predicted the intention to be screened and (b) personal background factors, including sociodemographic factors, previous screening experience, economic status, and perceived risk, indirectly influenced the intention to be screened through their effects on cognitive components such as attitude and subjective norm in the theory of planned behavior model. Most of the personal background factors did not directly influence intention but instead influenced cognitive elements in the theory of planned behavior model. Attitude and perceived behavioral control were well correlated with a patient's intention, regardless of the screening cost.</P>

A Study on automatic survey of road information for PMS maintenance

Hahm, Chang Hahk(함창학),Joo, Yong Jin(주용진),Won, SungMin(원성민) 한국측량학회 2013 한국측량학회 학술대회자료집 Vol.2013 No.4