• ETRI Journal
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• v.17 no.3
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• pp.17-43
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• 1995

We present a comprehensive derivation of the transport of holes involving an interacting two-valence-band system in terms of a generalized relaxation time approach. We sole a pair of semiclassical Boltzmann equations in a general way first, and then employ the conventional relaxation time concept to simplify the results. For polar optical phonon scattering, we develop a simple method th compensate for the inherent deficiencies in the relaxation time concept and apply it to calculate effective relaxation times separately for each band. Also, formulas for scattering rates and momentum relaxation times for the two-band model are presented for all the major scattering mechanisms for p-type GaAs for simple, practical mobility calculations. Finally, in the newly proposed theoretical frame-work, first-principles calculations for the Hall mobility and Hall factor of p-type GaAs at room temperature are carried out with no adjustable parameters in order to obtain a direct comparison between the theory and recent available experimental results, which would stimulate further analysis toward better understanding of the complex transport properties of the valence band. The calculated Hall mobilities show a general agreement with our experimental data for carbon doped p-GaAs samples in a range of degenerate hole densities. The calculated Hall factors show $r_H$=1.25~1.75 over all hole densities($2{\times}10^{17}{\sim}1{\times}10^{20}cm^{-3}$ considered in the calculations.

• Journal of the Korean Magnetics Society
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• v.23 no.3
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• pp.89-93
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• 2013

In this study, magnetic concentrators which could be used to enhance sensitivity of Hall effect sensor were analyzed by using FEM. The parameters for FEM analysis were the thickness and edge shape of magnetic concentrator and relative position of magnetic concentrator against Hall element. Magnetic field in z direction decreased with increasing of the thickness of magnetic concentrator, of which tendency was similar to apparent relative permeability calculated with demagnetizing factor of magnetic concentrator. There were optimal thickness and edge shape of magnetic concentrator according to the relative position of magnetic concentrator against Hall element.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.234-252
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• 2023

This study looked at the modification of major gardens while making Deoksugung Palace (德壽宮) a park in the Japanese colonial era. This is because landscaping work was carried out in various places from 1932 to 1933 to open Deoksugung Palace, which used to be an imperial palace, as a public recreation space. In particular, major gardens such as the front yard of Seokjojeon Hall (石造殿), the back yard of Hamnyeongjeon Hall (咸寧殿), and the back yard of Jeukjodang Hall (卽阼堂) were greatly transformed into different shapes from the original. During the first phase of construction in 1932, a water tank was installed in Seokjojeon Hall Garden, creating the first water space. This water tank was originally a structure installed in the front yard of Injeongjeon Hall (仁政殿) of Changdeokgung Palace (昌德宮). Around 1909, a water tank installed in the front yard of Injeongjeon Hall was relocated to Seokjojeon Garden in the process of turning Deoksugung Palace into a park. The water tank moved from the front yard of Injeongjeon Hall was a factor that transformed the central area of Seokjojeon Garden into a water space, and a fountain installed to replace the water tank remains to this day. The backyard of Hamnyeongjeon Hall was also renovated into a new shape during the first phase of construction. Originally, there was a terraced flowerbed called Hwagye (花階) in the backyard of Hamyujae Hall (咸有齋) and Hamnyeongjeon Hall, and it was restored from the construction that took place after the Great Fire of Deoksugung Palace. In the process of turning Deoksugung Palace into a park, a three-stage stonework was built in the front yard of Jeonggwanheon Pavilion (靜觀軒) which renovated the Hwagye in the backyard of Hamyujae Hall and Hamnyeongjeon Halll. The stonework built at that time was used as a peony garden to provide visitors with attractions after the opening of Deoksugung Palace, and it remains today with the name Jeonggwanheon's Hwagye. The backyard of the Jeukjodang Hall area is a case of damage in the second phase of construction in 1933. Like the backyard of Hamnyeongjeon Hall, the backyard of Jeukjodang Hall, where the Hwagye was originally built, was converted into a Japanese-style garden in the process of turning Deoksugung Palace into a park. The site where the Hwagye was demolished was decorated with a Japanese-style garden centered on mounding, small roads, and landscaping stones, as well as topographic control and planting work. Although there have been minor changes since liberation, the backyard of the Jeukjodang Hall area is still based on a Japanese-style garden created by turning Deoksugung Palace into a park.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.138-139
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• 2006

Metal organic chemical vapor deposition has been investigated for growth of $Sb_{2-x}Bi_xTe_3$ films on (001) GaAs substrates using diisopropyltelluride, triethylantimony and trimethylbismuth as metal organic sources. The thermoelectric properties were measured at room temperature and include Seebeck coefficient, electrical conductivity and Hall effect. In-plane carrier concentration and electrical Hall mobility were highly dependent on precursor's composition ratio and deposition temperature. The thermoelectric Power factor($={\alpha}^2{\sigma}$) was calculated from theses properties. The best Power factor was $2.6\;{\times}\;10^{-3}W/mK^2$, given by grown $Sb_{1.6}Bi_{0.4}Te_3$ at $450^{\circ}C$. These materials could potentially be incorporated into advanced thermoelectric unicouples for a variety of power generation applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.108-113
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• 2005

In this study, rotary type diamond dressing system for ultra-precision centerless grinding for ferrule was developed at the first time and experiments were conducted with AE sensor and hall sensor system to verify the optimum dressing condition for ultra-precision centerless grinding for ferrule. The correlations with the condition of dressing are evaluated by AE signal analysis with root mean square (RMS) and frequency analysis. And current signals from hall sensor are also studied as a factor of dressing optimum condition selection. Dressing process was conducted to investigate the effects of depth of cut, rotating speed, and the number of overlap to select the optimum condition of rotary dressing system of ultra-precision centerless grinding machine for ferrule fabrication. In order to verify the optimum condition of dressing, AE and current signals were compared with the surface quality of dressing wheel and grinding wheel for ultra-precision ferrule grinding. All of these experiments were completed by Taguchi Methodology to reduce experimental time. Hence, the optimum condition of rotary dressing system for ultra-precision centerless grinding for ferrule fabrication can be selected following to the experiment result from signals of AE and hall sensor.

• Korean Institute of Interior Design Journal
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• v.15 no.5 s.58
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• pp.265-272
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• 2006

Traditionally exhibition design as been restricted to architectural, interior, and lighting design, but recently it has begun to overlap into environmental, performance, and installation art. Exhibition design also increasingly involves the application of film, fashion, and the new media. In the past, exhibits were arranged and displayed for the visitor to view directly, but with the development of more effective exhibit media a connection has been created between the exhibit and the visitor. However exhibition design has reached the limits of continuous growth without background theory, when now it must take Into consideration the museum's activation and the importance of the exhibition's design. Exhibition design has developed and grown rapidly since the Taejeon Expo in 1993, but it is a difficult development without a theoretical structure. The flow of exhibition design must be systemized, as the systemization of the transition process of exhibition design has not yet been achieved. This study aims to present an arrangement of exhibition design flow, and to investigate the variation factors in the transition process of exhibition design and exhibit medium development, based on the 18 year history of the Independence Hall that introduced the first systematic planning of an exhibition in 1987.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.51-55
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• 2004

$CdS_{0.69}Se_{0.31}$ single crystal grown by sublimation method. Hall effect measurement were carried out by the Van der Pauw method. The measurement values under the temperature were found to be carrier density $n=1.95{\times}10^{23}m^{-3}$, Hall coeffcient $RH=3.21{\times}10^{-5}m^3/c$, conductivity ${\sigma}=362.41{\Omega}^{-1}m^{-1}$, and Hall mobility ${\mu}=1.16{\times}10^{-2}m^2/v.s.$ Heterojunction solar cells of $n-CdS_{0.69}Se_{0.31}/p-Cu_{2-x}S_{0.69}Se_{0.31}$ were fabricated by the substitution reaction. The open-circuit voltage, short-circuit currint density, fill factor and power conversion efficiency of $n-CdS_{0.69}Se_{0.31}/p-Cu_{2-x}S_{0.69}Se_{0.31}$ heterojunction solar cell under $80mW/cm^2$ illumination were found to be 0.41V, $19.5mA/cm^2$, 0.75 and 9.99%, respectivity.

• Culinary science and hospitality research
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• v.10 no.4
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• pp.1-14
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• 2004

This study investigates and analyzes the diversity of menu in military meal services that are recognized by the soldiers who are familar with meal services and, suggest the implications on the results of the analysis. For the ranks of respondents in terms of demographic features, the sergeants were 43.2%(186), the corporals were 29.7%(128). It was identified that the diversity of menu had significant influences as 57.5%. Thus, for the satisfaction on the kitchen and mess hall service, the sanitary condition was the most considerable factor as 41.6%. Next, water supply facilities, sewer hygiene and towels in washstaynds were the issues to be considered more. In conclusion, this study was limited only to the air soldiers in Chungcheon. Then, the future study needs to expand the samples more than this study to apply the results to the entire army. Moreover, the study could not be actively performed because of the particularity of the army. Consequently, it is required to make these kinds of researches dynamically performed like for any other meal service industries.

• Journal of Distribution Science
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• v.16 no.8
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• pp.15-27
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• 2018

Purpose - The purpose of the study is to examine the relationships among the following retail operations variables: retail store operations (i.e., store management, sales personnel, promotion of merchandise), success of assortment planning, firm performance (i.e., market share, overall competitive position, profitability, product quality, consumer satisfaction), and retail buyer's demographics and firm's characteristics. Research design, data, and methodology - After conducting a pilot test, the survey was conducted in Seoul, South Korea. With using the listwise deletion method, 378 usable data sets were analyzed. For data analysis, descriptive statistics, factor analysis, and Structural Equation Modeling (SEM) methods were employed. Results - As evidenced from the path diagram, the relationship between retail store operations and the success of assortment planning is strong and significant. Retail store operations affect firm performance, though at a weaker significance than it affects the success of assortment planning. The relationship between the success of assortment planning and firm performance, is the strongest relationship observed by this research. Conclusions - The findings of this empirical study contribute to the retail/fashion buying/management field by confirming (a) the importance of assortment planning for retail firm performance and (b) the role of store operations for successful assortment planning and firm performance for fashion retailers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.468-473
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• 2000

Recently the acoustic design has been considered the important part of architectural design. However, in the design of Catholic churches the exterior beauty is still main point. This study aims to find out the acoustical characteristics in the main hall of Catholic churches. Six catholic churches were selected for this experiment and the physical parameters which represent the acoustic characteristics of room were compared by the plan type and the architectural factor. The physical parameters compared and analyzed were SD(Stand deviation) of SPL(sound pressure level), RT(reverberation time), $D_{50}$(definition), $C_{80}$(clarity) and STI(speech transmission index).