• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.784-789
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• 2011

A linear spring model, where the interactions among atoms are assumed to be isotropic and elastic, is employed for the study of non-polar optical phonon scattering in the valence band of alloy semiconductors. The force equations of n atoms are used in the spring model for the consideration of the random distribution of constituent atoms in an alloy semiconductor. When the number of atoms in a unit cell is assumed to be two based on the experimental result, the optical deformation potent is valid for compound semiconductors as well as alloy semiconductors.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.220-221
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• 2023

Microsurgical peripheral nerve repair is a technical and challenging procedure that requires thorough training prior to a real-life operating theater scenario. While the gold standard in training remains training on biological living peripheral nerve specimen, various inanimate models of nerve repair simulation have been described in the past years. The textile elastic band (TEB) obtained from a surgical mask was either covered with a fine silicone sheath or was left bare and was used afterward for end-to-end coaptation. The average diameter of the TEB was 2 mm, similar with the nerves in the distal hand and can be easily crafted out of accessiblematerials such as a surgicalmask and silicone sealant. The silicone that covers the TEB offers more fidelity to the simulation for microsurgical nerve coaptation. The TEB model offers an affordable, available, and easy-to-craft alternative to the existing models for peripheral nerve repair simulation and serves as a good initiation tool before moving on to biological specimens.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.166-176
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• 1994

The problem of reducing the vibration level of elastic plates driven by multiple random point forces is analyzed in this study. First, the analytical solution for the vibration level of finite thin plates with four simply supported edges under the action of multiple random point force is derived. By assuming the plates to be lightly damped, an approximate solution for the vibration level of the plate is obtained. A numerical study is carried out to determine an optimal spacing distance between the multiple point forces in order to produce a relative minimum in the plate's vibration level. The optimal spacing distance is shown to depend on the given excitation band. The effects of wave cancellation in the near field of the multiple point forces are discussed by using the equivalence of certain stationary random responses and deterministic pulse responese.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1268-1280
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• 2019

The purpose of this study was to investigate the effects of combined exercise on irisin, body composition and glucose metabolism in obese elderly women with type 2 diabetes mellitus. The subjects were thirty-six obese elderly women with type 2 diabetes volunteers, aged 65 to 85 years, composed of the combined exercise type 2 diabetes mellitus group (n=20) and non-exercise type 2 diabetes mellitus group (n=16). The 60 minute combined exercise program (outdoor walking exercise & elastic-band exercise) was performed 3 times per week for 12 weeks. Exercise intensity of outdoor walking exercise was performed as medium intensity (RPE 5~6) and elastic-band exercise was progressively increased every four weeks (1-4 weeks: OMNI-RES 3~4, 5-8 weeks: OMNI-RES 5~6, 9-12 weeks: OMNI-RES 7~8). The results of the study in the combined exercise type 2 diabetes mellitus group were as follows; Irisin and skeletal muscle mass had significantly increased (p<.001), percentage of body fat had significantly decreased (p<.001). Further, HbA1c (p=.020) and fasting glucose (p<.001) was significantly decreased, and HOMA-β was significantly increased (p<.001). Correlation results showed that change of irisin had a significant negative correlation between percentage of body fat mass (r=-.423, p=.010), HbA1c (r=-.351, p=.036) and fasting glucose (r=-.424, p=.010). Also, irisin changes showed a positive correlation with aerobic endurance (r=.355, p=.034) and HOMA-β (r=.411, p=.013). In conclusion, the practice of regular combined exercise was found to increase the level of irisin in elderly women with type 2 diabetes and have a positive effect on body composition changes. In addition, HbA1c, fasting glucose and insulin secretion was improved, which helped to regulate glucose metabolism. Walking exercise and elastic band exercise are recommended as effective exercise for the prevention and management of diabetes in obese elderly women with type 2 diabetes mellitus.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.1
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• pp.13-24
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• 2013

Various elastic wave-based site investigation methods have been used to characterize subsurface ground because the dynamic properties can be correlated with various geotechnical parameters. Although the inherent spatial variability of the geotechnical parameters affects the P-wave propagation characteristics, ground heterogeneity has not been considered as an influential factor. Thus, the effect of heterogeneous ground on the travel-time shift and wavefront characteristics of elastic waves through stochastic numerical analyses is investigated in this study. The effects of the relative correlation lengths and relative propagation distances on the travel-time shift of P-waves considering various intensities of ground heterogeneity were investigated. Heterogeneous ground fields of stiffness (e.g., the coefficient of variation = 10 ~ 40%) were repeatedly realized in numerical finite difference grids using the turning band method. Monte Carlo simulations were undertaken to simulate P-wave propagation in heterogeneous ground using a finite difference method-based numerical approach. The results show that the disturbance of the wavefront becomes more significant with stronger heterogeneity and induces travel-time delays. The relative correlation lengths and propagation distances are systematically related to the travel-time shift.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.10
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• pp.1651-1658
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• 2008

This study was to decided the proper garment pressure level on the human body parts. Six volunteers (female: 30-40years) put on the same types of bands, a brief, and a non-woven gown. Garment pressure was measured in regular order with the elastic band on the human body parts such as the upper arm, the waist, the thigh, and the calf. At the same time, physiological responses such as the skin blood flow rate on 2 fingers, 7 different skin temperatures, rectal temperature, heat rates, and subjective responses about the pressure sensation, thermal sensation, and humidity sensation were measured and inquired. The results were as follows; 1. The thicker subcutaneous fat thickness, the higher the mean garment pressure on pressurizing the upper arm(p<.001). Also the thicker subcutaneous fat thickness. the thicker the upper arm circumference. 2. Heart rates increased pressured the upper arm and decreased pressured the waist, the thigh, and the calf. The higher the garment pressure, the higher heart rates on all body parts were pressured. Especially lean subjects showed higher physiological load than others. 3. On pressurizing the upper arm, heart rates, rectal temperature, and mean skin temperature were higher than without pressured state and pressured other body parts.4. The proper garment pressure levels were decided 30gf/$cm^2$ for fat people, 20gf/$cm^2$ for others on the upper arms and 24gf/$cm^2$ on the calf.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.1
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• pp.21-30
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• 2006

In case of an urban tunnel, the displacement of ground base controls the tunnel design because it is built on shallow and unconsolidated ground many times. There are more insufficiency to describe the ground movement which coincides in the measured result of the situ because the design of an urban tunnel is dependent on the method of numerical analysis used to the existing elastic and elasto-plastic models. We studied about the predict ion for the ground movement of a shallow tunnel in unconsolidated ground, mechanism of collapse, and settlement. Also this paper shows comparison with the existing elastic and elasto-plastic model using the unlinear analysis of the strain-softening model. We can model the real ground movement as the increasement of ground surface inclination or occurrence of shear band by using strain-softening model for the result of ground movement of an urban NATM tunnel.

• Women's Health Nursing
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• v.10 no.4
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• pp.301-310
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• 2004

Purpose: The purpose of this study was to develop an exercise program for postmastectomy patients. Method: This study was conducted from October, 2003 to June, 2004. The exercise program was developed based on literature review and needs assessment using focus group interviews. The subjects for the focus group interview consisted of 11 patients, 13 recovering patients, and 20 nurses from 3 hospitals. Development of the program was proceeded with analysusm design and development steps. Result: The results of the needs assessment using the focus group interview showed that the exercise program was imperative for postmastectomy patients. Based on the results, a home video tape containing 3 steps, was developed. Each step includes warming-up, stretching, the main exercise, and cool-down. Steps 2 and 3 include exercises with an elastic band, and an elastic ball. The program was modified after conducting a pre-test. A self-checklist including shoulder mobility, hand strength, arm volume and subjective comments on how they feel will be used before and after the exercise program. Conclusion: The exercise program will improve breast cancer patients' quality of life and their physical well-being. Further studies are recommended to test the effectiveness of the exercise program.

• Earthquakes and Structures
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• v.8 no.6
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• pp.1363-1386
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• 2015

The October 23 2011 Van Earthquake is studied from an earthquake engineering point of view. Strong ground motion processing was performed to investigate features of the earthquake source, forward directivity effects during the rupture process as well as local site effects. Strong motion characteristics were investigated in terms of peak ground motion and spectral acceleration values. Directiviy effects were discussed in detail via elastic response spectra and wide band spectograms to see the high frequency energy distributions. Source parameters and slip distribution results of the earthquake which had been proposed by different researchers were summarized. Influence of the source parameters on structural response were shown by comparing elastic response spectra of Muradiye synthetic records which were performed by broadband strong motion simulations of the earthquake. It has been emphasized that characteristics of the earthquake rupture dynamics and their effects on structural design might be investigated from a multidisciplinary point of view. Seismotectonic calculations (e.g., slip pattern, rupture velocity) may be extended relating different engineering parameters (e.g., interstorey drifts, spectral accelerations) across different disciplines while using code based seismic design approaches. Current state of the art building codes still far from fully reflecting earthquake source related parameters into design rules. Some of those deficiencies and recent efforts to overcome these problems were also mentioned. Next generation ground motion prediction equations (GMPEs) may be incorporated with certain site categories for site effects. Likewise in the 2011 Van Earthquake, Reverse/Oblique earthquakes indicate that GMPEs need to be feasible to a wider range of magnitudes and distances in engineering practice. Due to the reverse faulting with large slip and dip angles, vertical displacements along with directivity and fault normal effects might significantly affect the engineering structures. Main reason of excessive damage in the town of Erciş can be attributed to these factors. Such effects should be considered in advance through the establishment of vertical design spectra and effects might be incorporated in the available GMPEs.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.389-389
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• 2013

HfOx (Hafnium oxide)는 ~25의 고유전상수, 5.25 eV의 비교적 높은 Band-gap을 갖는 물질로 MOSFET (metal-oxide semiconductor field-effect-transistor) 구조의 Oxide 박막을 대체 가능한 물질로 연구가 지속되고 있다. 현재까지 진행된 대다수의 연구는 증착 조건에 따른 박막의 결정학적 및 전기적 특성에 대한 주제로 진행되었고 다양한 연구 결과가 보고된바 있다. 하지만 기존의 연구 기법은 박막의 nanomechanics 특성에 대한 연구가 부족하여 이를 보완하기 위한 연구가 절실하다. 따라서 본 연구에서는 HfOx 박막 내 포함된 산소가 고온 열처리 과정에서 빠져나감으로 인한 박막의 nanomechanics 특성을 확인하고자 하였다. 시료는 rf magnetron sputter를 이용하여Si (silicon) 기판위에 Hafnium target으로 산소유량(5, 10, 15 sccm)을 달리하여 증착하였고, 이후 furnace에서 $400^{\circ}C$에서 $1,000^{\circ}C$까지 질소분위기에서 20분간 열처리를 실시하였다. 실험결과 시료의 전기적 특성을 I-V 곡선을 측정하여 확인하였고, 증착 시 산소 유량이 5 sccm에서 15 sccm으로 증가함에 따라서 누설전류 특성은 급격히 향상되었고, 열처리 온도가 증가함에 따라 감소하는 특성을 나타내었다. 또한 시료의 nanomechanics 특성을 확인하기 위하여 nano-indenter를 이용하여 시료의 표면강도(surface hardness)와 탄성계수(elastic modulus)를 확인하였다. 측정결과 5 sccm 시료의 표면강도와 탄성계수는 상온에서 열처리 온도가 증가함에 따라 각각 7.75 GPa에서 9.19 GPa로, 그리고 133.83 GPa에서 126.64 GPa로 10, 15 sccm의 박막의 비하여 상대적으로 균일한 특성을 나타내었다. 이는 증착 시 박막 내 과포화된 산소가 열처리 과정에서 빠져나감으로 인한 것이며, 또한 과포화된 정도에 따라 더 적은 열처리 에너지에 의하여 박막을 빠져나감으로 인한 것으로 판단된다. 또한 열처리 과정에서 산소가 빠져나가는 상대적인 flux의 영향으로 인하여 박막의 mechanical한 균일도의 변화가 나타났다.