• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.12
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• pp.1165-1174
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• 2016

The energy band gaps and the bowing parameters of zincblende InAs1-xN are determined by using an empirical pseudopotential method(EPM) within the improved virtual crystal approximation(VCA), which includes the disorder effect. The direct-band-gap bowing parameter calculated by using the EPM is 4.1eV for InAs1-xNx ($0{\leq}x{\leq}0.05$). The dependences of the band gaps of N-dilute InAs1-xNx on the temperature and composition are calculated by modifying the band anti-crossing(BAC) model. The calculation results are consistent with experimental values, and the coupling parameter CMN of InAs1-xNx is found to be equal to 1.8 by fitting the EPM data.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.288.1-288.1
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• 2014

We investigated the optical properties of Ge1-xSex and Ge1-x-ySexAsy amorphous semiconductor films using spectroscopic ellipsometry and Raman spectroscopy. The dielectric functions and absorption coefficients of the amorphous films were determined from the measured ellipsometric angles. We obtained the optical gap energies and Urbach energies from the absorption coefficients, and found a strong bowing effect in the optical gap energy of Ge1-x-ySexAsy where the endpoint binaries were Ge0.50Se0.50 and Ge0.31As0.69. Based on the correlation between optical gap energies and Urbach energies, the large bowing parameter was attributed to the electronic disorder. We found the composition dependence of several phonon modes using Raman spectroscopy. For Ge1-x-ySexAsy, the D mode (232-267 cm-1) changed from As-As (or As3 pyramid), to As(Se1/2)3 pyramid, and finally to Se clusters, as the Se composition increased. Resonant Raman phenomenon was observed in Ge0.38Se0.62 at a laser excitation of 514 nm (2.41 eV). We verified that this laser energy corresponds to the transition energy of Ge0.38Se0.62 using the second derivative of the dielectric function of Ge0.38Se0.62.

• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.35-45
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• 2020

Photovoltaic (PV) power system prices have been steadily dropping in recent years due to their mass production and advances in relevant technology. Crystalline silicon (c-Si wafers) account for the largest share of the price of solar cells; reducing the thickness of these wafers is an essential part of increasing the price competitiveness of PV power systems. However, reducing the thickness of c-Si wafers is challenging; typically, phenomena such as bowing and cracking are encountered. While several approaches to address the bowing phenomenon of the c-Si solar cells exist, the only method to study the crack phenomenon (related to the strength of the c-Si solar cells) is the bending test method. Moreover, studies on determining the strength properties of the solar cells have focused largely on c-Si wafers, while those on the strength properties of front and rear-side electrodes and SiNx, the other components of c-Si solar cells, are scarce. In this study, we analyzed the strength characteristics of each layer of c-Si solar cells. The strength characteristics of the sawing mark direction produced during the production of c-Si wafers were also tested. Experiments were conducted using a 4bending tester for a specially manufactured c-Si solar cell. The results indicate that the back side electrode is the main component that experienced bowing, while the front electrode was the primary component regulating the strength of the c-Si solar cell.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.123-133
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• 2006

The main objective of this study is to develop an optimization algorithm of framed structures with rigid and various semi-rigid connections using the multilevel dynamic programming and the sequential unconstrained minimization techniques (SUMT). The second-order elastic analysis is performed for steel framed structures. The second order elastic analysis is developed based on nonlinear beam-column theory considering the bowing effect. The following semi-rigid connections are considered; double web angle, top-seat angle and top-seat angle with web angle. We considered the three connection models, such as modified exponential, polynomial and three parameter model. The total weight of the structural steel is used as the objective function in the optimization process. The dimensions of steel cross section are selected as the design variables. The design constraints consist of strength requirements for axial, shear and flexural resistance and serviceability requirements.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.85-90
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• 2014

In this paper, we propose a virtual violin implementation using the detection of bowing and finger dropping position from the estimated finger tip and finger board information with the 3D image data from a Kinect. Violin finger board pattern and depth information are extracted from the color image and depth image to detect the touch event on the violin finger board and to identify the touched position. Final decision of activated musical alphabet is carried out with the finger drop position and bowing information. Our virtual violin uses PC MIDI to output synthesized violin sound. The experimental results showed that the proposed method can detect finger drop position and bowing detection with high accuracy. Virtual violin can be utilized for the easy and convenient interface for a beginner to learn playing violin with the PC-based learning software.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.1
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• pp.51-54
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• 2013

False vocal fold hypertrophy caused by diverse pathologic lesion, such as laryngeal amyloidosis, laryngeal lipidosis, laryngocele, saccular cyst and sulcus vocalis. False vocal fold hypertrophy, however, is also caused laryngeal structure deformity, irrespective of pathologic lesions. In this article, we report some cases of false vocal fold hypertrophy caused by inward bowing of thyroid cartilage. At the clinic of the department of otorhinolaryngology in Gangnam Severance Hospital, with 3 male complained of hoarseness as subjects, and comfirmed of false vocal fold hypertrophy using the stroboscopy and larynx CT we checked vocal fold and laryngeal structure. Three patients with apparent hypertrophy of false vocal fold were investigated with computerized tomography (CT). In all patients, marked concavity of thyroid cartilage was revealed in CT scan at the level of the false vocal fold, and this deformity of the thyroid cartilage seemed to cause a protrusion of false vocal fold which taken as hypertrophy in stroboscopy. Careful palpation of the larynx and a CT scan taken at the level of the false vocal fold should be useful in determining whether hypertrophy of the false vocal fold is pathologic. For the next articles, It is necessary to discuss for the cause, diagnosis, treatment and prevention of inward bowing of thyroid cartilage.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1213-1222
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• 2018

The energy band gaps and the bowing parameters of zincblende $GaAs_{1-x}N_x$ on the variation of temperature and composition are determined by using an empirical pseudo-potential method with another virtual crystal approximation, which includes the disorder effect. The bowing parameter is calculated as 15eV and the energy band gaps are decreasing rapidly in $GaAs_{1-x}N_x$ ($0{\leq}x{\leq}0.05$, 300K). A refractive index n and a function of high-frequency dielectric constant ${\varepsilon}$ are calculated by the results of energy band gaps and the calculation results of energy band gaps are consistent with experimental values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.677-681
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• 2009

$In_xGa_{1-x}N$ alloys with 20-nm-thickness were deposited onto Mg:GaN/AlN/SiC substrates by MOCVD at $800\;^{\circ}C$. TMGa, TMIn and $NH_3$ were used as the precursor of gallium, indium and nitrogen, respectively. The mole ratio of indium in $In_xGa_{1-x}N$ films varied between 0 and 0.2. The energy-band-gaps of the films were obtained from the photoluminescence and cathodoluminescence peaks. The mole ratios of $In_xGa_{1-x}N$ films were calculated by applying Vegard's law to XRD results. The energy-band-gap versus indium composition plot for $In_xGa_{1-x}N$ alloys were well fit with a bowing parameter of 2.27.

• Archives of Plastic Surgery
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• v.49 no.6
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• pp.750-754
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• 2022

Trigger wrist, characterized by a clicking or snapping sensation around the wrist joint during finger or wrist motion, and bifid or trifid median nerve, which occurs in carpal tunnel syndrome along with anatomical variation of median nerve, are rare conditions. We report the case of a patient with a thickened tendon caused by severe tenosynovitis and flexor tendon subluxation to the hamate hook due to bowing of the flexor retinaculum, thereby resulting in trigger wrist as well as an anatomical median nerve variation (bifid median nerve in the right wrist and trifid median nerve in the left wrist). A 59-year-old housewife visited our hospital with bilateral fingertip numbness, tingling sensation, and aggravated severe night cramping that began 2 months ago. She also complained about trigger wrist during small finger flexion. Based on magnetic resonance imaging, ultrasonography, and nerve conduction study, trifid median nerve and bilateral severe median nerve neuropathy of the wrist were diagnosed; therefore, transverse carpal tunnel release and exploration under wide-awake anesthesia were planned. Intraoperative findings showed trifid and bifid median nerves in left and right wrists, respectively. Additionally, bowing of flexor retinaculum and severe flexor tendon tenosynovitis were observed. Tenosynovitis with thickened flexor sheath resulted in subluxation of the small finger flexor tendon above the hamate hook. After transverse carpal ligament release with antebrachial fascia release and tenosynovectomy, subluxation of the flexor tendon was resolved. At 6 months postoperatively, the tingling and dullness in fingertips also resolved, and no trigger wrist or any other complications were noted.

• Annals of Clinical Neurophysiology
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• v.4 no.2
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• pp.114-118
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• 2002

Backgrounds : Carpal tunnel syndrome (CTS) is a common condition that is usually diagnosed by electrophysiologic studies. However, CTS provide limited information to determine the causes of CTS and to choose the treatment method. We evaluated diagnostic sensitivity of MR imaging and treatment decisions by MR imaging in electrodiagnosed CTS. Methods : 14 patients (26 wrists) with electrodiagnosed CTS were studied using MR imaging. In 26 wrists for which axial T1 & T2 weighted images were obtained at 1.5T with a decided wrist coil. Previously described MR imaging of CTS such as increased median nerve signal, flattening of median nerve, reticular bowing, tenosynovitis and space occupying lesions were retrospectively evaluated. Degree of improvement was evaluated by global symptom score (GSS). The GSS rated symptoms from 0 (no symptoms) to 10 (severe) in each of five categories: pain, numbness, paresthesia, weakness/clumsiness, and nocturnal awakening. Subjects' GSS was recorded at baseline, 2 weeks, 1 month, 6 months after treatment. We decided to medical treatment that showed mainly inflammatory sign such as increased median nerve signal, tenosinovitis and to surgical treatment such as space occupying lesion, high canal pressure sign. Results : MR imaging showed that increased median nerve signal were in 20 wrists (77%), flattening of median nerve were in 6 wrists (23%), reticular bowing were in 3 wrists (12%), tenosynovitis were in 8 wrists (32%), decreased canal size in 2 wrists (7.6%), space occupying lesion were in 1 wrist (4%). A good outcome was revealed in 21 wrists by medical treatment that showed mainly increased median nerve signal, tenosynovitis. The mean GSS were 27.7 at baseline, 11.2 at 2 weeks, 11.0 at 6 months in medical treatment group. Another 5 wrist had surgical treatment shown by ganglion and high canal pressure sign such as median nerve flattening, reticular bowing, decreased canal size: 3 wrists had good prognosis, but 2 wrists (one patient) had no significant improvement due to small carpal tunnel size. Conclusions : Our results are in agreement with most previously described MR imaging signs of CTS. MR imaging plays an important role in several cases and especially in the assessment of failure of surgical treatment. Knowledge of MR findings may permit more rational choice of treatment.