한국산업표준(KS)에 따른 로크웰 경도 시험기의 불확도 산정에 관한 연구

탁내형,방건웅 한국열처리공학회 2000 熱處理工學會誌 Vol.13 No.3

Recently, uncertainty of hardeness became a major concern for the people working on the laboratory evaluation and accreditation. It is required to indicate uncertainty of hardness tester on the report after calibration. In addition to this, uncertainty of certified hardness reference block is also required to indicate on the certification sheet. Method on the evaluation of uncertainty in hardness measurement is agreed only recently for Rockwell hardness C scale. In this paper, a preliminary calculation of uncertainty based on type B evaluation has been made for hardness testers which satisfies the requirements of Korean Standards. It was found that the tolerance limit of mean value specified in KS should be increased to be compatible with the calculated uncertainty.

MICOM-Compatible ±4 1/2 Digit Analog to Digital Converter for Digital Multimeter Applications

Bahng, Sam Yong,Lee, Seong Ho,Choi, Eung Ju,Baek, Seung Bum,Kim, Suk Ki 대한전자공학회 1991 ICVC : International Conference on VLSI and CAD Vol.2 No.1

This paper reports a dual slope analog-to-digital To achieve high accuracy and high resolution, the converter working with a microcontroller to perform gain of integrator amplifier has to be high enough, complete digital multi-meter(DMM) functions. Auto-zeroing and X10 switched capacitor functions can be performed simultaneously to reduce offset errors as well as to improve the resolution of the UMM.

Modification of Surface Layer during High Temperature Annealing and its Effects on the SiC Diode Characteristics

Bahng, Wook,Cheong, Hui Jong,Kang, In Ho,Kim, Seong Jin,Kim, Sang Cheol,Joo, Sung Jae,Kim, Nam Kyun Trans Tech Publications, Ltd. 2007 Materials science forum Vol.556 No.-

<P>We have investigated the influence of surface modification on the electrical properties of SiC diodes. Schottky diodes (SBDs) as well as PiN diodes were fabricated on n-type SiC substrate with an epilayer, and electrically characterized before and after high temperature annealing, and after removing the surface modified layer, respectively. The devices annealed without graphite cap layer showed ohmic behavior. The surface layer was modified to a conductive layer possibly due to the preferred sublimation of Si species. In order to confirm the existence of modified surface conductive layer, diode was fabricated on the same substrate and electrically characterized after removing 30nm-thick damaged layer by ICP-RIE. The leakage current reduced dramatically, as much as 7 orders of magnitude. The PiN diodes fabricated on the damaged surface layer showed the reverse leakage current and the breakdown voltage of 50mA and 1250V, respectively. While those of the diode fabricated after removing the damaged surface layer were 200nA at the breakdown voltage of 2100V, respectively.</P>

Design and measurement of beam reconfigurable antenna based on folded dipole structure

Bahng, K.,Jung, C.W.,Kim, K. IET 2009 Electronics letters Vol.45 No.3

<P>A reconfigurable antenna based on a folded dipole structure has been designed to operate at 2.45 GHz. The antenna consists of a folded dipole and a reflector. Depending on the states of the switches, the antenna symmetrically changes its shape and thus steers the beam pattern. The measured reflection coefficient and radiation pattern are presented. Also, the antenna is shown to have a larger gain with the reflector than without.</P>

Viscosities of Supercooled Water and Other Liquids

Bahng, Jun-Su,Hahn, Sang-Joon,Jhon, Mu-Shik Korean Chemical Society 1971 대한화학회지 Vol.15 No.4

Significant structure theory has been applied to the viscosities of supercooled liquids with success. In the supercooled region, the effect of free volume decrease is so significant that the thermal effects on the solid-like volume must be considered properly. In addition, the two state theories proposed by Jhon and Eyring for water and Litovitz et al. for boron trioxide have been successfully applied to the structure change in the liquid state. Considered liquids are benzene, carbon tetrachloride, p-xylene, water and boron trioxide.

Apoptosis-Induced Gene Profiles of a Myeloma Cell P3-X63-Ag8.653

Bahng, Hye-Seung,Chung, Yong-Hoon The Korean Association of Immunobiologists 2006 Immune Network Vol.6 No.3

Background: Apoptosis is a physiologic phenomenon involved in development, elimination of damaged cells, and maintenance of cell homeostasis. Deregulation of apoptosis may cause diseases, such as cancers, immune diseases, and neurodegenerative disorders. The mouse myeloma cell P3-X63-Ag8.653 (v653) is an HGPRT deficient $(HGPRT^-)$ mutant strain. High dependency on de novo transcription and translation of aminopterin induced apoptosis of this cell seems to be an ideal experimental system for searching apoptosis-induced genes. Methods & Results: For searching apoptosis-related genes we carried out GE-array (dot blot), Affymetrix GeneChip analysis, Northern analysis and differential display-PCR techniques. The chip data were analyzed with three different programs. 66 genes were selected through Affymetrix GeneChip analyses. All genes selected were classified into 8 groups according to their known functions. They were Genes of 1) Cell growth/maintenance/death/enzyme, 2) Cell cycle, 3) Chaperone, 4) Cancer/disease-related genes, 5) Mitochondria, 6) Membrane protein/signal transduction, 7) Nuclear protein/nucleic acid binding/transcription binding and 8) Translation factor. Among these groups number of genes were the largest in the genes of cell growth/maintenance/death/enzyme. Expression signals of most of all groups were peaked at 3 hour of apoptosis except genes of Nuclear protein/nucleic acid binding/transcription factor which showed maximum signal at 1 hour. Conclusion: This study showed induction of wide range of proapoptotic factors which accelerate cell death at various stage of cell death. In addition apoptosis studied in this research can be classified as a type 2 which involves cytochrome c and caspase 9 especially in early stages of death. But It also has progressed to type 1 in late stage of the death process.

Ensemble and Single-Molecule Spectroscopic Study on Excitation Energy Transfer Processes in 1,3-Phenylene-Linked Perylenebisimide Oligomers

Bahng, Hee Won,Yoon, Min-Chul,Lee, Ji-Eun,Murase, Yuichi,Yoneda, Tomoki,Shinokubo, Hiroshi,Osuka, Atsuhiro,Kim, Dongho American Chemical Society 2012 The Journal of physical chemistry B Vol.116 No.4

<P>1,3-Phenylene-bridged perylenebisimide dimer (<B>PBI2</B>) and trimer (<B>PBI3</B>) were prepared along with monomer reference (<B>PBI1</B>) using perylene imide-anhydride <B>5</B> as a key precursor. 3,3-Dimethylbut-1-yl substituents were introduced at the 2,5-positions of perylenebisimide (PBI) to improve the solubilities of <B>PBI</B> oligomers. Actually, no serious aggregation of <B>PBI2</B> and <B>PBI3</B> was detected in their dilute CH<SUB>2</SUB>Cl<SUB>2</SUB> solutions. Under these conditions, intramolecular electronic interactions among PBI chromophores have been revealed by measuring the photophysical properties at their ensemble and single-molecule levels. The excitation energy transfer times of <B>PBI2</B> (0.16 ps) and <B>PBI3</B> (0.60 ps) were determined from the two different observables, anisotropy depolarization, and singlet–singlet annihilation, respectively, which are considered as the incoherent Förster-type energy hopping (EEH) times as compared with the EEH time constant (1.97 ps) calculated on the basis of the Förster mechanism. The relatively short EEH times compared to similar PBI oligomers can be attributed to 1,3-phenylene linker, which assures a short distance between the chromophores and, as a consequence, makes it hard to treat the PBI unit as a point dipole. The limitation of point-dipole approximation to describe the PBI oligomers and additional through-bond type interactions can be attributed as the causes of the discrepancies in excitation energy transfer times. Considering these photophysical properties, we can suggest that 1,3-phenylene-linked PBI oligomers have potentials as molecular photonic devices including the artificial light-harvesting system.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpcbfk/2012/jpcbfk.2012.116.issue-4/jp208855u/production/images/medium/jp-2011-08855u_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp208855u'>ACS Electronic Supporting Info</A></P>

Trench Formation on Ion Implanted SiC Surfaces after Thermal Oxidation

Bahng, Wook,Song, Geun Ho,Kim, Nam Kyun,Kim, Sang Cheol,Kim, Hyoung Wook,Seo, K.S.,Kim, Eun Dong Trans Tech Publications, Ltd. 2005 Materials science forum Vol.483 No.-

<P>The effects of the damage induced during ion implantation on the surface roughening and oxide growth rate were investigated. Using several scheme of doses and acceleration energies, it is found that the amount of the dose predominantly produce damage rather than the acceleration energy, especially near the surface region. It was also found that the damage affects not only the oxide growth rate but also the surface roughening during high temperature annealing. The edge of highly implanted area may have higher doping concentration due to the vicinal side wall effect of the thick oxide mask for ion implantation. It was confirmed by the trench formation after thermal oxide remove.</P>

Comparison of Design Preferences in the Hawaiian Shirt and Current Market

Bahng, Youngjin,Reilly, Andrew The Society of Fashion and Textile Industry 2018 한국의류산업학회지 Vol.20 No.4

The Hawaiian shirt, also known as the Aloha shirt, is a short-sleeved, colorful shirt with traditional Polynesian designs (e.g., hibiscus, fish) originating in Hawai'i. The shirt was selected for study because it is a unique garment that originated in the Hawaiian Islands in the late $19^{th}$ and $20^{th}$ centuries and marketed as a tourist product but was eventually adopted as appropriate residential clothing by the $mid-20^{th}$ century, however with different aesthetic details. Today, it is assumed by Hawaiian Island residents that tourists demonstrate poor taste when selecting a Hawaiian shirt. The purposes of this study are to examine the validity of the assumption that tourist taste and resident taste in Hawaiian shirts are different and to investigate the current Hawaiian shirt market change. For this study, 555 questionnaires were obtained from tourists and residents, and 10 Hawaiian shirt retailers/wholesalers participated in in-depth interviews. The results indicated that differences do exist between tourists' and residents' preferences for print designs and colorway. The market change of Hawaiian shirts was also recognizable in that an increasing number of tourists select Hawaiian shirts similar to resident customers, as part of their routine lives rather than as holiday or vacation garments. Other differences in Hawaiian shirt shopping behavior included the findings that tourists consider fabrication less important than resident customers who consider fabrication more (i.e., cotton 100%). By using both quantitative and qualitative methods, this study contributes to the fashion design and marketing field as well as help manufacturers and retailers with their merchandise and distribution plans.

Molecular engineering and solvent dependence of excitation energy hopping in self-assembled porphyrin boxes

Bahng, Hee Won,Kim, Pyosang,Sung, Young Mo,Maeda, Chihiro,Osuka, Atsuhiro,Kim, Dongho The Royal Society of Chemistry 2012 Chemical communications Vol.48 No.35

<P>It has been demonstrated that the direction and magnitude of transition dipole moments, and hence rates in the excitation energy hopping in the self-assembled porphyrin boxes can be tuned by insertion of ethynyl groups as well as the dielectric constant of solvent.</P> <P>Graphic Abstract</P><P>Excitation energy hopping in self-assembled porphyrin boxes. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cc30834g'> </P>