• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.178-186
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• 1999

Twenty-three patients with chronic shoulder pain beyond 6 months after the fracture of the greater tuberosity underwent arthroscopic treatment and were retrospectively assessed after an average of 29 months(range, 22 to 40 months). There were 18 men and 5 women with the average age of 39 years(range, 24 to 61 years). Fourteen were isolated fractures and nine were related to acute anterior instability episode. The average displacement of the fracture was 2.3mm(range, 0 to 4mm) on the anteroposterior view of the plane radiographs. At the time of arthroscopy, all patients had partial thickness rotator cuff tears in the articular surface. The cuff tears were located on the tuberosity fracture area and were an Ellman's grade I to n in depth. With the arthroscopic debridement or repair of the tear depending on the condition of the tear itself, as well as the subacromial decompression, the UCLA score revealed good to excellent results in 20 and fair in 3 patients. Nineteen of the patients had returned to the previous level of activities. The patient with a higher activity demand revealed a lower level of activity return(p=0.034). The partial thickness rotator cuff tear should be considered in patients with chronic shoulder pain after the minimally displaced fracture of the greater tuberosity, and arthroscopic debridement or repair is an appropriate procedure.

• Imaging Science in Dentistry
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• v.38 no.4
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• pp.203-208
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• 2008

Purpose : The purpose of this study was to develop a system for the measurement and simulation of the TMJ movement and to analyze the mandibular movement quantitatively. Materials and Methods : We devised patient-specific splints and a registration body for the TMJ movement tracking. The mandibular movements of the 12 subjects with facial deformity and 3 controls were obtained by using an optical tracking system and the patient-specific splints. The mandibular part was manually segmented from the CT volume data of a patient. Three-dimensional surface models of the maxilla and the mandible were constructed using the segmented data. The continuous movement of the mandible with respect to the maxilla could be simulated by applying the recorded positions sequentially. Trajectories of the selected reference points were calculated during simulation and analyzed. Results : The selected points were the most superior point of bilateral condyle, lower incisor point, and pogonion. There were significant differences (P<0.05) between control group and pre-surgical group in the maximum displacement of left superior condyle, lower incisor, and pogonion in vertical direction. Differences in the maximum lengths of the right and the left condyle were 0.59${\pm}$0.30 mm in pre-surgical group and 2.69${\pm}$2.63 mm in control group, which showed a significant difference (P<0.005). The maximum of differences between lengths of the right and the left calculated during one cycle also showed a significant difference between two groups (P<0.05). Conclusion : Significant differences in mandibular movements between the groups implies that facial deformity have an effect on the movement asymmetry of the mandible. (Korean J Oral Maxillofac Radiol 2008; 38 : 203-8)

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.278-285
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• 2003

This study was performed to compare early stage changes following the administrations of Conjugated Linoleic Acid (CLA), Carprofen and their combinations in the experimental canine cranial cruciate ligament rupture. Twenty five mongrel dogs were divided into five groups; Groups 1, 2, and 3 received a sectioning the cranial cruciate ligament (CCL) of the right stifle joint, and were administered CLA (250 mg/kg/day/orally), carprofen (4.4 mg/kg/day/orally), and their combinations for 4 weeks beginning 4 weeks postsurgery, respectively. Group 4 received sectioning CCL and no treatment. Group 5 was composed of unoperated normal dogs. The macroscopic observation of cartilage erosions on both the condyles and plateaus were evaluated, and the severity of the cartilage lesions and synovial inflammation was examined histologically at eight weeks after surgery. Histological examinations including hematoxylin and eosin stain, standard toluidine blue method, PAS technique and Masson trichrome technique, hematologic and radiographic evaluation were perfonned after experimental surgery. Slight yellowish discoloration of the surface was found in some of the experimental dogs. However macroscopic findings showed no significant differences among the groups. In radiographic findings, cranial displacement of the proximal tibia relative to the femoral condyles in all groups was observed but no significant differences among the groups was seen. This study showed that oral administration of CLA, carprofen and their combinations revealed no early stage change in the canine stifle joint following experimental rupture of the cranial cruciate ligament.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6A
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• pp.457-464
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• 2011

An experimental study was performed to evaluate the possibility of using stiff type PolyUrea(PU) on RC slab as a strengthening material. Stiff type PU(STPU) was sprayed on the bottom surface of the slab specimens, which were then attached with CFRP or GFRP sheets. Also the evaluation of the bond capacity, the single most influential parameter on strengthening of RC structures, was carried out the flexural capacity evaluation test results showed that the load carrying capacity of the PU specimen was greater and less than the unstrengthened and FRP sheet attached specimens, respectively. The STPU specimens showed a ductile flexural behavior in the plastic displacement range. With respect to bond capacity, the bond strength of all of the specimen exceeded the code required bond strength of 1.5 MPa. Also, the STPU sprayed specimen without using epoxy resin did not peel off when the tensile grip was applied for testing. The stability of the PU bond failure indicate a good bond strength of PU when applied to concrete.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.740-746
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• 2011

The variations of catch of anchovy and saury due to oceanic climate change in the Korean Seas were studied. This study area was $31^{\circ}{\sim}38^{\circ}$ N and $124^{\circ}{\sim}132^{\circ}$ E. And data (seawater temperature, salinity, dissolved oxygen) is used from NFRDI (National Fisheries Research and Development Institute) and SST (Sea Surface temperature) obtained to satellite images (NOAA/AVHRR) during 2000 to 2009. The spatial characteristics are analyzed by GIS (Geographic Information System). The results showed that the average of seawater temperature in the depth of 20m increased $1.45^{\circ}C$ in the South Sea and $0.83^{\circ}C$ in the East Sea, respectively. The maximal catch of anchovy was highest in summer (July~September) and winter (December~March), respectively, in compared with spring (April~June). Catch of anchovy has increased since 2000. The maximal catch of saury was highest in spring (May~June), in compared with spring (August~September). The increment of seawater temperature contributed to increase the catch of anchovy, but catch of saury was decrease in the same times.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.403-415
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• 2014

Recently, the temperature rise in the summer due to climate change, power usage is increasing rapidly. As a result, power generation facilities have been newly completed and the need for ultra-high-voltage transmission line for power transmission of electricity to the urban area has increased. The mechanized tunnelling method using a shield TBM have an advantage that it can minimize vibrations transmitted to the ground and ground subsidence as compared with the conventional tunnelling method. Despite the popularity of shield TBM for cable tunnel construction, study on the mechanical behavior of cable tunnel driven by shield TBM is insufficient. Thus, in this study, the effect of fractured zone ahead of tunnel face on the mechanical behavior of the shield TBM cable tunnel is investigated. In addition, it is intended to compare the behavior characteristics of the fractured zone with continuous model and applying the interface elements. Tunnelling with shield TBM is simulated using 3D FEM. According to the change of the direction and magnitude of the fractured zone, Sectional forces such as axial force, shear force and bending moment are monitored and vertical displacement at the ground surface is measured. Based on the stability analysis with the results obtained from the numerical analysis, it is possible to predict fractured zone ahead of the shield TBM and ensure the stability of the tunnel structure.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.163-169
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• 2019

Sn-Pb solder alloys in electronics rapidly has been replaced to Pb free solder alloys because of various environmental regulations such as restriction of hazardous substances directive (RoHS), European Union waste electrical, waste electrical and electronic equipment (WEEE), registration evaluation authorization and of chemicals (REACH) etc. Because Sn58%Bi (in wt.%) solder alloy has low melting point and higher mechanical properties than that of Sn-Pb solder, it has been studied to manufacture electronic components. However, the reliability of Sn58%Bi solder could be lowered because of the brittleness of Bi element included in the solder alloy. Therefore, we observed the microstructures of Sn58%Bi composite solders with various contents of Sn-decorated multiwalled carbon nanotube (Sn-MWCNT) particles and evaluated bonding strength of the FR-4 components assembled with Sn58%Bi composite solder. Also, microstructures and bonding strengths of the Sn58%Bi composite solder joints were evaluated with the number of reflows from 1 to 7 times, respectively. Bonding strengths and fracture energies of the Sn58%Bi composite solder joints were measured by die shear test. Microstructures and fracture modes were observed with scanning electron microscope (SEM). Microstructures in the Sn58%Bi composite solder joints were finer than that of only Sn58%Bi solder joint. Bonding strength and fracture energy of Sn58%Bi composite solder including 0.1 wt.% of Sn-decorated MWCNT particles increased up to 20.4% and 15.4% at 5 times in reflow, respectively.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.305-311
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• 2000

Applicability of crack arrest load measured from the Charpy V-notch impact test has been investigated to predict the fracture toughness of nuclear reactor pressure vessel (RPV) steels (ASME SA508 Cl.3). The temperature dependence of the crack arrest load was well described by the type of exponential function characterized by an index temperature at which the crack arrest load is 2kN. The specific index temperature, which also well correlated with $T_{NDT}\;and\;T_{41J}$ is expected to be representative index temperature characterizing the crack arrest fracture toughness of RPV steels. Also, the crack arrest load correlated well with the stable crack length measured from the fracture surface. From the measurements of the crack arrest load and the stable crack length, the lower bound fracture toughness, $K_{Ia}$ of RPV steels could be predicted with sufficient accuracy.

• Journal of Korea Game Society
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• v.7 no.4
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• pp.71-80
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• 2007

In this paper, we introduce an efficient GPU-based real-time rendering technique applicable to every kind of game. Our method, without an extra geometry, can represent terrain just with a height map. It makes it possible to freely go around in the air or on the surface, so we can directly apply it to any computer games as well as a virtual reality. Since our method is not based on any geometrical structure, it doesn't need special LOD policy and the precision of geometrical representation and visual quality absolutely depend on the resolution of height map and color map. Moreover, GPU-only technique allows the general CPU to be dedicated to more general work, and as a result, enhances the overall performance of the computer. To date, there have been many researches related to the terrain representation, but most of them rely on CPU or confmed its applications to flight simulation, Improving existing displacement mapping techniques and applying it to our terrain rendering, we completely ruled out the problems, such as cracking, poping etc, which cause in polygon-based techniques, The most important contributions are to efficiently deal with arbitrary LOS(Line Of Sight) and dramatically improve visual quality during walk-through by reconstructing a height field with curved patches. We suggest a simple and useful method for calculating ray-patch intersections. We implemented all these on GPU 100%, and got tens to hundreds of framerates with height maps a variety of resolutions$(256{\times}256\;to\;4096{\times}4096)$.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.792-795
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• 2008

AGT system is a kind of light railway train. AGT system use of concrete track and rubber tire, so it can be reduce the noise and vibration, compare to the normal train system. And, the dynamic responses of normal bridge are influenced by the dynamic characteristics of bridge, the speed of vehicle and the surface roughness of railway. But the AGT system bridge is influenced not only the above facts but also the guiderail unevenness, because, AGT vehicle steered by guiderail. So, in this study, optimized service condition is suggested for the design and operation of AGT system, by the means of experimental study. The experiments are executed for PSC bridge with length of 30m, at the AGT test line in Kyongsan. The test results are compared and investigated according to the prominence. In the test result, the guiderail prominence influenced on the dynamic response of bridge. It shows a increase as compared with no guiderail prominence in the dynamic response value acceleration, displacement, stain.