• Journal of the Korea institute for structural maintenance and inspection
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• 제21권6호
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• pp.44-51
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• 2017

Recently, the parking in downtown area has caused severe problem due to the dramatic increase of possessing automobile in the country. A parking structure has been on the spotlight to solve the parking problem in downtown area. However, the overall height of parking structure is stipulated less than 8 m. Therefore, in this research, 'wide composite beam', which is possible for reducing story height and having long span, is developed and the flexural capacity of the wide composite beam is evaluated. Based on the result of the flexural test, the flexural strength of wide composite beam increased by 20% as the thickness of steel beam increased by 3 mm ($6mm{\rightarrow}9mm$) The shapes of rebar (whether it is triangle or rectangular shape) in the wide composite beam did not affect its flexural strength. The flexural strength of wide composite beam without rebar decreased by 10% compared to that of wide composite beam with rebar. In addition, the neutral axis moved upward as a load increased, but the neutral axis moved downward, when the load exceeded a certain level of load.

• Journal of the Korean Wood Science and Technology
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• 제37권4호
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• pp.364-371
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• 2009

This study was carried out to investigate the bending strength of the Larix glulam beams which were reinforced with CFRP (Carbon fiber reinforced plastic) of which the reinforcement ratios were 0.7% and 2.1% by volume. In the bending test, the rupture shape of the reinforced glulam shows that the reinforced glulam broke firstly in the lowest bottom layer on which tension was loaded, but did not in the upper part reinforced with the CFRP layer. The upper part of the reinforced layer kept strength and did not break when the reinforced glulam broke firstly at the bottom part of the reinforced layer, but broke secondly as loading was increased. In the glulam beams reinforced with CFRP of which the reinforcement ratio was 0.7% by volume, the bending strength of the reinforced beams was increased by 28% at the first break. When beams broke up to the upper part of the reinforced layer, the bending strength of the reinforced beams was increased by 55%, compared to those of control glulam beams. When the glulam beams were reinforced with CFRP of which the reinforcement ratio was 2.1% by volume, the bending strength of the reinforced beams was increased by 77%, compared to those of control glulam beams. The ratio of the height of calculated neutral axis using failure mode recommended by Romani and the height of actual neutral axis using strain gauge was 1.03 and agreed well.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제14권6호
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• pp.445-454
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• 2001

The stochiometric mix of evaporating materials for the CuInSe$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CuInSe$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were 62$0^{\circ}C$ and 41$0^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of CuInSe$_2$ single crystal thin films measured from Hall effect fby van der Pauw method are 9.62x10$^{16}$ cm$^{-3}$ , 296$\textrm{cm}^2$/V.s at 293 K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuInSe$_2$ single crystal thin film we have found that he values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 6.1 meV and 175.2 meV at 10K, respectively. From the photoluminescence measurement on CuInSe$_2$ single crystal thin film we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton (D$^{\circ}$,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excition were 7meV and 5.9meV, respectivity. by Haynes rule, an activation energy of impurity was 50 meV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.266-272
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• 2002

The stochiometric mixture of evaporating materials for the ZnIn$_2$S$_4$ single crystal thin film was prepared from horizontal furnace. To obtain the ZnIn$_2$S$_4$ single crystal thin film, ZnIn$_2$S$_4$ mixed crystal was deposited on throughly etched semi-insulating GaAs(100) in the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were 610 $^{\circ}C$ and 450 $^{\circ}C$, respectively and the growth rate of the ZnIn$_2$S$_4$ single crystal thin film was about 0.5 $\mu\textrm{m}$/hr. The crystalline structure of ZnIn$_2$S$_4$ single crystal thin film was investigated by photo1uminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of ZnIn$_2$S$_4$ single crystal thin film measured from Hall effect by van der Pauw method are 8.51${\times}$10$\^$17/ cm$\^$-3/, 291 $\textrm{cm}^2$/V$.$s at 293 $^{\circ}$K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the ZnIn$_2$S$_4$ single crystal thin film, we have found that the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 0.0148 eV and 0.1678 eV at 10 $^{\circ}$K, respectively. From the photoluminescence measurement of ZnIn$_2$S$_4$ single crystal thin film, we observed free excition (E$\_$X/) typically observed only in high quality crystal and neutral donor bound exciton (D$^{\circ}$,X) having very strong peak intensity. The full width at half maximum and binding energy of neutral donor bound excition were 9 meV and 26 meV, respectively. The activation energy of impurity measured by Haynes rule was 130 meV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.171-174
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• 2004

The stochiometric $AgGaSe_2$ polycrystalline mixture of evaporating materials for the $AgGaSe_2$ single crystal thin film was prepared from horizontal furnace. To obtain the single crystal thin films, $AgGaSe_2$ mixed crystal and semi-insulating GaAs(100) wafer were used as source material and substrate for the Hot Wall Epitaxy (HWE) system, respectively. The source and substrate temperature were fixed at $630^{\circ}C$ and $420^{\circ}C$, respectively. The thickness of grown single crystal thin films is $2.1{\mu}m$. The single crystal thin films were investigated by photoluminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of $AgGaSe_2$ single crystal thin films measured from Hall effect by van der Pauw method are $4.89{\times}10^{17}\;cm^{-3},\;129cm^2/V{\cdot}s$ at 293K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the $AgGaSe_2$ single crystal thin film, we have found that the values of spin orbit splitting ${\Delta}S_o$ and the crystal field splitting ${\Delta}C_r$ were 0.1762 eV and 0.2494 eV at 10 K, respectively. From the photoluminescence measurement of $AgGaSe_2$ single crystal thin film, we observed free excition $(E_X)$ observable only in high quality crystal and neutral bound exciton $(D^o,X)$ having very strong peak intensity And, the full width at half maximum and binding energy of neutral donor bound excition were 8 meV and 14.1 meV, respectively. By Haynes rule, an activation energy of impurity was 141 meV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.163-166
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• 2001

The stochiometric mix of evaporating materials for the $ZnGa_{2}Se_{4}$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $ZnGa_{2}Se_{4}$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $610^{\circ}C$ and $450^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $ZnGa_{2}Se_{4}$ single crystal trun films measured from Hall effect by van der Pauw method are $9.63{\times}10^{17}cm^{-3}$, $296cm^{2}/V{\cdot}s$ at 293 K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c axis of the $ZnGa_{2}Se_{4}$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$ So and the crystal field splitting $\Delta$Cr were 251.9 meV and 183.2 meV at 10 K, respectively. From the photoluminescence measurement on $ZnGa_{2}Se_{4}$ single crystal thin film, we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton $(A^{0},X)$ having very strong peak intensity. Then, the full-width-at -half-maximum(FWHM) and binding energy of neutral acceptor bound excition were 11 meV and 24.4 meV, respectivity. By Haynes rule, an activation energy of impurity was 122 meV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.167-170
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• 2001

The stochiometric mix of evaporating materials for the $CdGa_{2}Se_{4}$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CdGa_{2}Se_{4}$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $630^{\circ}C$ and $420^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CdGa_{2}Se_{4}$ single crystal thin films measured from Hall effect by van der Pauw method are $8.27{\times}10^{17}cm^{-3},345cm^{2}/V{\cdot}s$ at 293 K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $CuInSe_{2}$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$ So and the crystal field splitting $\Delta$Cr were 106.5 meV and 418.9 meV at 10 K, respectively. From the photoluminescence measurement on $CdGa_{2}Se_{4}$ single crystal thin film, we observed free excition (Ex) existing only high Quality crystal and neutral bound exiciton $(D^{0},X)$ having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excition were 8 meV and 13.7 meV, respectivity. By Haynes rule, an activation energy of impurity was 137 meV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.167-170
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• 2001

The stochiometric mix of evaporating materials for the CdGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CdGa$_2$Se$_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 630$^{\circ}C$ and 420$^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of CdGa$_2$Se$_4$ single crystal thin films measured from Hall erect by van der Pauw method are 8.27x10$\^$17/ cm$\^$-3/, 345 $\textrm{cm}^2$/V$.$s at 293 K, respectively. From the Photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuInSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 106.5 meV and 418.9 meV at 10 K, respectively. From the photoluminescence measurement on CdGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$\_$X/) existing only high quality crystal and neutral bound exiciton (D$\^$0/,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excision were 8 meV and 13.7 meV, respectivity. By Haynes rule, an activation energy of impurity was 137 meV,

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.163-166
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• 2001

The stochiometric mix of evaporating materials for the ZnGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, ZnGa$_2$Se$_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 61$0^{\circ}C$ and 45$0^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of ZnGa$_2$Se$_4$ single crystal thin films measured from Hall effect by van der Pauw method are 9.63x10$^{17}$ cm$^{-3}$ , 296 $\textrm{cm}^2$/V.s at 293 K, respectively, From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the ZnGa$_2$Se$_4$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$So and the crystal field splitting $\Delta$Cr were 251.9 MeV and 183.2 meV at 10 K, respectively. From the photoluminescence measurement on ZnGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$_{x}$) existing only high quality crystal and neutral bound excition (A$^{0}$ ,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral acceptor bound excition were 11 meV and 24.4 meV, respectivity. By Haynes rule, an activation energy of impurity was 122 meV.on energy of impurity was 122 meV.

• Journal of Korean Neurosurgical Society
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• 제60권5호
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• pp.560-566
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• 2017

Objectvie : The global sagittal postural patterns as characterized by Roussouly classification have been previously described in various ethnicities, there were no studies investigated in Koreans. To analyze the distribution of the global sagittal postural patterns in Korean adults using Roussouly classification, the author prospectively studied. Methods : 252 asymptomatic Korean adults was recruited. Data was obtained by reviewing the films for each subject. Spinopelvic parameters were measured and sagittal postural patterns were then determined according to Roussouly classification. We compared the data across different ethnicities from our study and a previous study to further characterize Korean sagittal postures. Results : The subject included 151 males and 101 females, with mean age of $33.2{\pm}8.2years$. The average descriptive results were as below : thoracic kyphosis $28.6{\pm}7.7^{\circ}$, lumbar lordosis $48.3{\pm}10.2^{\circ}$, sacral slope $37.8{\pm}5.8^{\circ}$, pelvic incidence $45.1{\pm}7.5^{\circ}$, pelvic tilt $9.4{\pm}6.7^{\circ}$, spinosacral angle $130.1{\pm}5.4^{\circ}$, and sagittal vertical axis $16.25{\pm}22.5mm$. 125 subjects among 252 (49.6%) belonged to Roussouly type 3 (namely neutral). There were also 58 (23%), 33 (13.1%), and 36 (14.3) subjects in type 1, 2, and 4 (namely non-neutral), respectively. Conclusion : Enrolling 252 asymptomatic Korean adults, this prospective study found that 49.6% of asymptomatic Korean adults possessed a sagittal posture of Roussouly type 3. All radiologic parameters follows general concept of spinal sagittal balance pattern. Overall, this study might be a basis for further investigation of spinal sagittal balance.