• Current Optics and Photonics
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• 제8권1호
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• pp.56-64
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• 2024

In response to the current situation where general methods cannot effectively compensate for the phase delay of ordinary optical mixers, a multi-layer spatial beam-splitting optical mixer is designed using total reflection triangular prisms and polarization beam splittings. The phase delay is generated by the wave plate, and the mixer can use the existing parallel plates in the structure to individually compensate for the phase of the four output beams. A mixer model is established based on the structure, and the influence of the position and orientation of the optical components on the phase delay is analyzed. The feasibility of the phase compensation method is simulated and analyzed. The results show that the mixer can effectively compensate for the four outputs of the optical mixer over a wide range. The mixer has a compact structure, good performance, and significant advantages in phase error control, production, and tuning, making it suitable for free-space coherent optical communication systems.

• 한국세라믹학회지
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• 제40권4호
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• pp.380-384
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• 2003

The effects of the mole concentrations of precursor solution on the microstructure and dielectric properties of sol-gel deposited $Ba_{0.85}$S $r_{0.15}$Ti $O_3$(BST) thin films have been investigated. The films were of single perovskite phase with strong (100) preferred orientation when grown on LaNi0$_3$ buffered Pt/Ti/ $SiO_2$Si substrates using a diluted precursor solution. Variation of the precursor solution concentration resulted in a different microstructure and, in turn, affected the tunability of the sol-gel deposited films. It was observed that leakage currents increased asymmetrically for the negative and positive bias voltage with decreasing thickness. Overall results suggest that those BST films have acceptable properties f3r applications as room-temperature tunable elements.

• 한국결정성장학회지
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• 제7권1호
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• pp.117-125
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• 1997

강탄성 $CsPbCl_3$ 결정을 Czochralski법 및 Bridgman법을 사용하여 육성하고 XRD, DTA, 유전상수 측정 등을 통하여 구조 조사 및 상전이 온도를 확인하고 편광현미경 조사를 통하여 강탄성 domain의 존재를 확인하였으며 domain의 온도 의존성 등을 관찰하였다. 또한 cubic상에서 tetragonal, orthorhombic을 거쳐 monoclinic으로 상전이하였을 때 나타나는 domain들의 orientation에 대해 결정학적 고찰을 통하여 그리고 이론적으로 조사하여 일치되는 결과를 얻었다.

• 열처리공학회지
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• 제27권2호
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• pp.79-89
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• 2014

The effect of carbon on the microstructure and texture of low carbon steels was investigated in a series of 1.6 Mn-0.3Cr-0.2Mo-0.001B steels with carbon ranging from 0.021 to 0.048%. Intensity of {111} orientation increased with decreasing the carbon content, resulting in the increase in $r_m$ value. The highest $r_m$ value of 1.30 was obtained in 0.021%C steel annealed at $820{\sim}850^{\circ}C$ according to the typical galvannealing heat cycle. Martensite volume fraction was not substantially affected by the annealing temperature. It was found that the fine and uniformly distributed martensite particles which were present in amounts of about 5% volume fraction were desirable for the highest $r_m$ value. The other factor affecting the high $r_m$ value was the preferred epitaxial growth of retained ferrite with {111} orientation into austenite during cooling.

• 한국의류학회지
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• 제36권2호
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• pp.152-164
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• 2012

This study develops a valid and reliable scale to evaluate customer orientation for clothing salespeople in order to provide a foundation for systematic and empirical research in the apparel industry. The study was conducted in two phases. First, a scale was developed to evaluate the customer orientation of clothing salespeople through a qualitative method. The second phase involved the verification of the validity of the developed evaluation questions through a quantitative method. The subjects of this study were 327 clothing salespeople, and the results were analyzed using AMOS 7.0 and SPSS 15.0. The results were as follows: First, customer orientation questions were elicited from in-depth interviews with fashion sales-people, analyses of fashion magazine articles, and previous studies. From the results, 38 preliminary questions were selected based on categorization, modification, and expert analyses of the content validity. Second, in order to verify the validity of the customer orientation scale that consisted of 24 questions in 7 factors, we performed a verification of the convergent validity through an assessment of the magnitude of standardization factor loading, average variance extracted (AVE), and construct reliability. Discriminant validity was verified using the AVE of each of the two constructs and a comparison of the square of the correlation between the constructs. According to the results, the measured values were above or near the guideline values that demonstrates the validity of the customer orientation scale.

• 대한금속재료학회지
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• 제50권1호
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• pp.78-85
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• 2012

Aluminum nitride(AlN) is a compound (III-V group) of hexagonal system with a crystal structure. Its Wurzite phase is a very wide band gap semiconductor material. It has not only a high thermal conductivity, a high electrical resistance, a high electrical insulating constant, a high breakdown voltage and an excellent mechanical strength but also stable thermal and chemical characteristics. This study is on the preferred orientation characteristics of AlN thin films by reactive evaporation using $NH_3$. We have manufactured an AlN thin film and then have checked the crystal structure and the preferred orientation by using an X-ray diffractometer and have also observed the microstructure with TEM and AlN chemical structure with FT-IR. We can manufacture an excellent AlN thin film by reactive evaporation using $NH_3$ under 873 K of substrate temperature. The AlN thin film growth is dependent on Al supplying and $NH_3$ has been found to be effective as a source of $N_2$. However, the nuclear structure of AlN did not occur randomly around the substrate a particle of the a-axis orientation in fast growth speed becomes an earlier crystal structure and is shown to have an a-axis preferred orientation. Therefore, reactive evaporation using $NH_3$ is not affected by provided $H_2$ amount and this can be an easy a-axis orientation method.

• Journal of Welding and Joining
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• 제19권4호
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• pp.423-428
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• 2001

The bonding phenomena of Ni base single crystal superalloy. CMSX-4 during transient liquid phase(TLP) bonding was investigated using MBF-80 insert metal. Bonding of CMSX-4 was carried out at 1,373∼1,548K for 0∼19.6ks in vacuum. The (001) orientation of each test specimen was aligned perpendicular to the bonding interface. The dissolution width of base metal was increased when the bonding temperature and holding time were increased. The eutectic width diminished linearly with the square root of holding time during isothermal solidification process. Borides were formed in the bonded layer during TLP bonding operation. The solid phase grew epitaxially into the liquid phase from substrates and single crystallization could be readily achieved during the isothermal solidification.

• 열처리공학회지
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• 제23권2호
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• pp.96-103
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• 2010

$Ni_3Al$ is known as a good high temperature structural material because of high yield strength at ambient temperature. However, it is too brittle to use as a structural material because of their weak grain boundary. In this work, orientation measurement and related mechanical properties of directionally solidified NiAl/$Ni_3Al$ two-phase alloys with various compositions (Ni-23~27 at.%Al) were investigated for developing multi-phase DS-processed alloys with the growth rates of 10, 50 and 100 ${\mu}m/s$ in a modified Bridgeman type furnace. It was found that the multi-phase microstructures such as the $\gamma$ dendrite +${\gamma}'$ matrix duplex microstructure was formed in the hypoeutectic composition of 23 at.%Al, $\beta$ dendrite +${\gamma}'$ matrix duplex microstructure in the hypereutectic composition of 26 and 27 at.%Al. And ${\gamma}'$ single phase was formed in the composition of 24.5 and 25 at.%Al. The hypoeutectic alloy including $\gamma$ dendrites with ${\gamma}'$ matrix showed a large elongation of over 70% at room temperature. However, the room-temperature tensile elongation decreased with increasing Al contents because the volume fraction of brittle $\beta$ dendrites in the ductile ${\gamma}'$ matrix increased.

• 한국전문물리치료학회지
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• 제26권4호
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• pp.53-62
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• 2019

Background: Shoulder function is achieved by the coordinated movements of the scapula, humerus, and thoracic spine, and shoulder disorders can be associated with altered scapular kinematics. The trunk plays an important role as the kinematic chain during arm elevation. Objects: The purpose of this study was to determine the effects of thoracic hyperkyphosis on scapular orientation and trunk motion. Methods: Thirty-one subjects (15 in the ideal thorax group and 16 in the thoracic hyperkyphosis group) performed right-arm abduction and adduction movements in an unconstrained plane. The scapular orientation and trunk motion were recorded using a motion analysis system. Results: Those subjects with thoracic hyperkyphosis displayed greater scapular posterior tilting at a $120^{\circ}$ shoulder elevation, greater scapular internal rotation throughout the arm raising phase, and greater trunk axial rotation at the upper ranges of the shoulder elevation, compared to those subjects with an ideal thorax (p<.05). Conclusion: Thoracic hyperkyphosis can cause scapular instability, greater trunk rotation and greater scapular posterior tilting, and may contribute to preventing the achievement of a full range of humeral abductions in an unconstrained plane.

• 전자공학회논문지B
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• 제29B권2호
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• pp.9-17
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• 1992

In recent years, object-orientation is rising to notice as a new paradigm for developing software. This paper suggests the diagramming technique and a tool for developing C++ program effectively. This technique can represent the modularity and the interactions of classes definitely by emphasizing the characteristics of classes of C++. It can do the direct mapping from the logical idea to the physical screen image, so programmers can reuse the design resources in design phase as well as transforming the resources into chode in the implementation phase.