• Clinics in Shoulder and Elbow
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• v.3 no.2
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• pp.79-86
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• 2000

Purpose: We analysed the clinical efficacy of inferior capsular shift operation in multidirectional instability of the shoulder joint in terms of functional aspects and patient's satisfaction Materials and Methods: From July, 1998 to March, 2000, we treated 23 cases of multidirectional instability of the shoulder joint with T-shaped inferior capsular shift and/or Bankart repair. All of them have complained of an experience about frank dislocations. Two of them has a voluntary component. We evaluated them according to complication, function, range of motion, stability and patient's satisfaction with an average follow-up of 15 months(the range of 9 to 27 months). Results: Eight cases were atraumatic multidirectional instability and coexisting Bankart lesion were present in 15. There was no redislocation, but one case of symptomatic subluxation, 3 cases of transient nerve palsy and 2 cases of feeling of laxity developed. Limitation of motion after surgery was an average of 3.4° in flexion, and 8.5° in external rotation. With Rowe scoring system, the clinical result was excellent or good in 22 cases and poor in one. According to American shoulder and elbow society, pain score improved to 1.4 from 6.1, and stability score also improved to 1.8 from 9.1. Conclusion: In multidirectional shoulder instability, one should pay attention to finding a coexisting Bankart lesion. In that case, adequate capsular volume reduction by using inferior capsular shift as well as repair of Bankart lesion is needed to get a good surgical outcome.

• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.159-165
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• 2014

Background: Kirschner's wire (K-wire) transfixation and locking hook plate fixation techniques are widely used in the treatment of acute acromioclavicular joint (ACJ) dislocation. The purpose of this study was to compare the clinical and radiologic outcomes between K-wires transfixation and a locking hook plate fixation technique. Methods: Seventy-seven patients with acute ACJ dislocation managed with K-wire (56 shoulders) and locking hook plate (21 shoulders) were enrolled for this study. The mean follow-up period was 61 months. Results: At the last follow-up, the shoulder rating scale of the University of California at Los Angeles (UCLA) was higher in patients treated with locking hook plate than with K-wires ($33.2{\pm}2.7$ vs. $31.3{\pm}3.4$, p=0.009). In radiologic assessments, coracoclavicular distance (CCD) (7.9 mm vs. 7.7 mm, p=0.269) and acromioclavicular distance (ACD) (3.0 mm vs. 1.9 mm, p=0.082) were not statistically different from contralateral unaffected shoulder in locking hook plate fixation group, but acromioclavicular interval (ACI) was significant difference. However, there were significant differences in ACI, CCD, and ACD in K-wire fixation group (p<0.001). Eleven complications (20%) occurred in K-wire transfixation group and 2 subacromial erosions on computed tomography scan occurred in locking hook plate fixation group. Conclusions: ACJ stabilization was achieved in acute ACJ dislocations treated with K-wires or locking hook plates. Locking hook plate can provide higher UCLA shoulder score than K-wire and maintain CCD, and ACD without ligament reconstruction. K-wire transfixation technique resulted in a higher complication rate than locking hook plate.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.195-200
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• 2017

Background: This study investigated and evaluated the clinical outcomes of intra-articular lesions of traumatic anterior shoulder dislocation (TASD) associated with greater tuberosity (GT) fracture of the humerus. Methods: Subjects included 20 patients who were surgically or non-surgically treated for GT fracture of the humeurs with TASD, and followed-up for at least 2 years. The mean follow-up period was 54.1 months (range, 24-105 months). Of the 20 patients, 12 were treated surgically. Intra-articular lesions were identified randomly on magnetic resonance imaging scans (repeated thrice) by experienced radiologists and orthopedic surgeons. The accompanying intra-articular lesions were left untreated. Clinical outcomes were evaluated by Simple Shoulder Test (SST) and Western Ontario Shoulder Instability index (WOSI) at the last follow-up. Results: Intra-articular lesions were identified in 19 patients: 7 Bankart lesions, 15 humeral avulsion of the glenohumeral ligament lesions, 3 glenoid avulsion of the glenohumeral ligament lesion, and 6 inferior capsular tears. Two or more intra-articular lesions were identified in 6 patients. The mean SST score was 10.9 and the mean WOSI score was 449.3 at the last follow-up. Conclusions: For GT fracture of the humerus with TASD, a high frequency of diverse intra-articular lesions was identified. There were no incidence of recurrent shoulder dislocations, and good clinical outcomes were obtained without treatment of the intra-articular lesions. We thereby comprehend that although intra-articular lesions may occur in TASD associated with GT fracture of the humeurs, merely treating the GT fracture of the humerus is sufficient.

• Korean Security Journal
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• no.10
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• pp.409-441
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• 2005

During reformation of the world order in the 21st century, the terrorism has been showing up as a new value and rising up as core element of determining human being's quality of lives. The middle east's terrorism is leading the international terrorism and it is originated from the religious ideology which has formed for centuries and struggles for regional influence. This is the conflict aspect coming from the opposition of religious ideologies and cultural dislocations. It concludes as confrontation between the terrorism of Islam fundamentalism and western christianity that America is leading after the terrorist attack on the World Trade Center on September 11, 2001. There is little prospect for an improvement of their relationship. The Terrorism supported by government might be eradicated by America's drastic anti-terrorism policy. However, it will be serious and spread all over the world that the terrorist attacks against America and western countries is acted by militant warriors of Islamic fundamentalism, uniting Arab and Islamic peoples' emotions against America. Terrorism is urgent menace to Korea and it is needed to take measures to cope with it considering their religion and people throughly.

• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.22-26
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• 2001

Microstructures of AlN thin films on Si substrates grown by plasma assisted molecular beam epitaxy were analyzed with various growth temperatures and substrate orientations. Reflection high energy electron diffraction (RHEED) patterns were checked for the in-situ monitoring of the growth condition. X-ray diffraction(XRD), double crystal X-ray diffraction (DCXD), and transmission electron microscopy/diffraction (TEM/TED) techniques were employed to characterize the microstructure of the films after growth. On Si(100) sub-strates, AlN thin films were grown mostly along the hexagonal c-axis orientation at temperature higher than $850^{\circ}C$. On the other hand the AlN films on Si(111) were epitaxially grown with directional coherencies in AlN(0001)/Si(111), AlN(1100)/Si(110), and AlN(1120)/Si(112). The microstructure of AlN thin films on Si(111) substrates, with a full width at half maximum of almost 3000 arcsec at 2$\theta$=$36.2^{\circ}$, showed that the single crystal films were grown, even if they includ a lot of crystal defects such as dislocations and stacking faults.

• Korean Journal of Materials Research
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• v.26 no.4
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• pp.167-172
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• 2016

The high temperature deformation behavior of $Ni_3Al$ and $Ni_3(Al,Mo)$ single crystals that were oriented near <112> was investigated at low strain rates in the temperature range above the flow stress peak temperature. Three types of behavior were found under the present experimental conditions. In the relatively high strain rate region, the strain rate dependence of the flow stress is small, and the deformation may be controlled by the dislocation glide mainly on the {001} slip plane in both crystals. At low strain rates, the octahedral glide is still active in $Ni_3Al$ above the peak temperature, but the active slip system in $Ni_3(Al,Mo)$ changes from octahedral glide to cube glide at the peak temperature. These results suggest that the deformation rate controlling mechanism of $Ni_3Al$ is viscous glide of dislocations by the <110>{111} slip, whereas that of $Ni_3(Al,Mo)$ is a recovery process of dislocation climb in the substructures formed by the <110>{001} slip. The results of TEM observation show that the characteristics of dislocation structures are uniform distribution in $Ni_3Al$ and subboundary formation in $Ni_3(Al,Mo)$. Activation energies for deformation in $Ni_3Al$ and $Ni_3(Al,Mo)$ were obtained in the low strain rate region. The values of the activation energy are 360 kJ/mol for $Ni_3Al$ and 300 kJ/mol for $Ni_3(Al,Mo)$.

• Korean Journal of Materials Research
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• v.21 no.3
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• pp.161-167
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• 2011

The stress-strain responses and oxidation properties of cold-rolled Zr-1.5Nb-O and Zr-1.5Nb-O-S alloys were studied. The U.T.S. (ultimate tensile strength) of cold-rolled Zr-1.5Nb-O-S alloy with 160 ppm sulfur (765 MPa) were greater than that of Zr-1Nb-1Sn-0.1Fe alloy (750 MPa), achieving an excellent mechanical strength even after the elimination of Sn, an effective solution strengthening element. The addition of sulfur increased the strength at the expense of ductility. However, the ductile fracture behavior was observed both in Zr-Nb-O and Zr-Nb-O-S alloys. The beneficial effect of sulphur on the strengthening was observed in the cold rolled Zr-1.5Nb-O-S alloys. The activation volume of cold-rolled Zr-1.5Nb decreased with sulfur content in the temperature region of dynamic strain aging associated with oxygen atoms. Insensitivity of the activation volume to the dislocation density and the decrease of the activation volume at a higher temperature where the dynamic strain aging occurs support the suggestion linking the activation volume with the activated bulge of dislocations limited by segregation of oxygen and sulfur atoms. The addition of sulfur was also found to improve the oxidation resistance of Zr-Nb-O alloys.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.645-651
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• 2014

GaN is most commonly used to make LED elements. But, due to differences of the thermal expansion coefficient and lattice mismatch with sapphire, dislocations have occurred at about $109{\sim}1010/cm^2$. Generally, a low temperature GaN buffer layer is used between the GaN layer and the sapphire substrate in order to reduce the dislocation density and improve the characteristics of the thin film, and thus to increase the efficiency of the LED. Further, patterned sapphire substrate (PSS) are applied to improve the light extraction efficiency. In this experiment, using an AlN buffer layer on PSS in place of the GaN buffer layer that is used mainly to improve the properties of the GaN film, light extraction efficiency and overall properties of the thin film are improved at the same time. The AlN buffer layer was deposited by using a sputter and the AlN buffer layer thickness was determined to be 25 nm through XRD analysis after growing the GaN film at $1070^{\circ}C$ on the AlN buffer CPSS (C-plane Patterned Sapphire Substrate, AlN buffer 25 nm, 100 nm, 200 nm, 300 nm). The GaN film layer formed by applying a 2 step epitaxial lateral overgrowth (ELOG) process, and by changing temperatures ($1020{\sim}1070^{\circ}C$) and pressures (85~300 Torr). To confirm the surface morphology, we used SEM, AFM, and optical microscopy. To analyze the properties (dislocation density and crystallinity) of a thin film, we used HR-XRD and Cathodoluminescence.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.713-719
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• 2000

In order to Prepare the$Ge_xSi_{1-x}/Si$(111) heterosructure by solid phase epitaxy (SPE), about 1000A of Au and about 1000A Ge were sequentially deposited on the Si(111) substrate. The resulting Ge/Au/Si(111) samples were isochronically annealed in the high vacuum condition. The behaviors of Au and Ge during thermal annealing and the structural Properties of $Ge_xSi_{1-x}$ films were characterized by Auger electron spectroscopy (AES), X-ray diffraction (XRD) and high resolution transmission electron microscopy (TEM). The a-Ge/Au/Si(111) structure was converted to the Au/GeSi/Si(111) structure. Defects such as stacking faults, point defects and dislocations were found at the GeXSil-X(111) interface, but the film was grown epitaxially with the matching face relationship of $Ge_xSi_{1-x}/$(111)/Si(111). Twin crystals were also found in the $Ge_xSi_{1-x}/$(111) matrix.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.41-44
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• 2001

The muscular button holing of vastus medialis is a very rare case of irreducible knee dislocations, and rapid reduction of this can diminish the complications which delayed reduction accompanies. We diagnosed a patient who appeared posterolateral dislocation of the knee and protrusion of the medial femoral condyle with MRI grossly. That was reduced by open arthrotomy, followed the reconstruction of both cruciate ligaments and repair of medial collateral ligament. Patient didn't show joint instability except minor posterior sagging and had full range of motion postoperatively after 10 months.