• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.76-76
• /
• 2010

Using ab initio density functional calculations, we investigate the structural and electronic properties of porous schwarzite structures formed by $sp^2$ carbon minimal surfaces with negative Gaussian curvature. We calculate the equilibrium geometries, elastic properties and electronic structure of two systems with cubic unit cells containing 152 and 200 carbon atoms, which are metallic and very rigid. The porous schwarzite structure can be efficiently doped by electron donors as well as accepors, making it a promising candidate for the next generation of alkali ion batteries. Furthermore, the schwarzite structures can be magnetic when doped and thus act as arrays of interconnected quantum spin dots. We also propose that two interpenetrating schwarzite structures be used as a ultimate super-capacitor.

• Journal of Gastric Cancer
• /
• v.11 no.2
• /
• pp.122-125
• /
• 2011

We report a rare case of the coexistence of a gastric small cell neuroendocrine carcinoma with a gastric adenocarcinoma. A 62-year-old man presented with epigastric soreness for 1 month. Esophagogastroduodenoscopy revealed a Borrmann type I tumor at the lesser curvature of the lower body of the stomach. The patient underwent a distal gastrectomy with D2 lymph node dissection and the resected specimen exhibited a $3.5{\times}3.5$ cm sized, fungating lesion. Two separated, not intermingling, lesions with non-adenocarcinoma components encircled by well differentiated adenocarcinoma components were identified microscopically. The non-adenocarcinoma component showed neuroendocrine features, such as a solid and trabecular pattern, and the tumor cells showed a high nuclear grade with minimal cytoplasm, indistinct nucleoli, and positive response for synaptophysin, CD56. The final pathological diagnosis was a gastric mixed exocrine-endocrine carcinoma (MEEC) composed of an adenocarcinoma and small cell neuroendocrine carcinoma of the collision type.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.4
• /
• pp.6-13
• /
• 2012

In this paper, we took an indirect reflectance type that irradiates light from an LED module, which reflects light from a reflector onto the road. This LED pedestrian lighting design produces minimal glare from a relatively simple structure. Using LightTools 7.2, we conducted a study on the varying shape and curvature of the reflector. In order to further investigate this data, we researched the ratio of the DLOR and ULOR, the average illuminance, and the uniformity of the illumination. Based on this research, we selected optimum conditions to realize the actual LED pedestrian lighting using RELUX software. We found the average illuminance value to be 22[1x] and the illuminance uniformity ratio to be 0.23, which met the criteria of the proposed standards set in KS C 7658. In addition, it also satisfied the criteria of the standards set in KS A 3701 by having TI (Threshold Increment) at 7[%].

• Journal of Industrial Convergence
• /
• v.20 no.1
• /
• pp.107-114
• /
• 2022

Scoliosis is defined as a condition in which the spine curves more than 10 degrees in frontal plane. However, it is complicated because it involves transverse and sagittal components as well as the frontal plane. Curvature can progress to growing children and cause serious problems. Treatments of Scoliosis, including observation, are casting, braces, physical therapy, exercise, and surgery. The goal of scoliosis management is to achieve minimal asymmetry by maintaining low angle values. However, it is difficult for adolescents to receive continuous treatment due to study and lack of time. We report cases of scoliosis that have experienced improvement of Cobb's angle through spinal thermal massage management at home.

• Journal of the Korea Concrete Institute
• /
• v.27 no.3
• /
• pp.207-214
• /
• 2015

This study examined the feasibility of wire ropes as lateral reinforcement at the boundary element of heavyweight concrete shear walls. The spacing of the wire ropes varied from 60 mm to 120 mm at an interval of 30 mm, which produces the volumetric index of the lateral reinforcement of 0.126~0.234. The wire ropes were applied as a external hoop and/or internal cross-tie. Five shear wall specimens were tested to failure under constant axial load and cyclic lateral loads. Test results showed that with the increase of the volumetric index of the lateral reinforcement, the ductility of shear walls tended to increase, whereas the variation of flexural capacity of walls was minimal. The flexural capacity of shear walls tested was slightly higher than predictions determined from ACI 318-11 procedure. The displacement ductility ratio of shear walls with wire ropes was higher than that of shear wall with the conventional mild bar at the same the volumetric index of the lateral reinforcement. In particular, the shear walls with wire rope index of 0.233 achieved the curvature ductility ratio of more than 16 required for high-ductility design.

• Journal of Yeungnam Medical Science
• /
• v.4 no.2
• /
• pp.75-81
• /
• 1987

Bone grafts are an integral and important aspect of craniofacial reconstruction. Ribs, tibia, and iliac bone have traditionally used as donor site but each of these has various problems, however using to the calvarial bone as a donor site has several advantage. These are as follows ; there are abundance of material, easy to reach the donor site through coronal incision, minimal pain of donor area, less functional inability, shorter hospitalization, no need of immobilization, hidden scar at donor site, no secondary deformity and appropriate curvature obtained properly selected. From march to December 1987, we experienced three cases of autogenous calvarial bone graft such as congenital saddle nose deformity, fibrous dysplasia on the right side frontal bone, and deviated nose. The results were very excellent without any significant complication. The detail technique of autogenous calvarial bone graft and its advantages compared with the traditional methods of bone grafts are discussed.

• Journal of the Korean Society of Radiology
• /
• v.14 no.3
• /
• pp.235-243
• /
• 2020

Lumbar Lordosis Angle (LLA) is an index that can be used to evaluate the curvature of the lumbar vertebrae. It can measure the structural stability of the lumbar spine and the stability of each segment of the vertebral column at the intervertebral disc angle (IDA). Especially, our data shows it is found to be a strong positive correlation between obesity and the angle of lordosis for lumbar vertebrae. Also, the reason for the large IDA in the case of obesity seems to be the result of the weakening of anatomical structure as well as the gravity effect. And, the obesity interferes with normal sagittal balance and fails to maintain a straight posture with minimal energy. Therefore, the obesity can be an important factor in causing back pain by changing the lumbar lordosis.

• The Journal of the Korea Contents Association
• /
• v.8 no.5
• /
• pp.94-103
• /
• 2008

In this paper, we adapt the $\kappa$-means clustering technique to segmenting a given 3D mesh. In order to avoid the locally minimal convergence and speed up the computing time, first we extract sharp vertices from the mesh by analysing its curvature and convexity that respectively reflect the local and global geometric characteristics from the viewpoint of cognitive science. Next the sharp vertices are partitioned into $\kappa$ clusters by iterated converging with the $\kappa$-means clustering method based on the geodesic distance instead of the Euclidean distance between each pair of the sharp vertices. For obtaining the effective result of $\kappa$-means clustering method, it is crucial to assign an initial value to $\kappa$ appropriately. Hence, we automatically compute a reasonable number of clusters as an initial value of $\kappa$. Finally the mesh segmentation is completed by merging other vertices except the sharp vertices into the nearest cluster by geodesic distance.

• Journal of Gastric Cancer
• /
• v.15 no.4
• /
• pp.278-285
• /
• 2015

Purpose: Gastric submucosal tumors (SMTs) located very close to the esophagogastric junction (EGJ) are a challenge for gastric surgeons. Therefore, this study reports on the experience of using endoscopic and laparoscopic full-thickness resection (ELFR) with laparoscopic two-layer suturing in such tumors. Materials and Methods: Six patients with gastric SMTs very close to the EGJ underwent ELFR with laparoscopic two-layer suturing at Kyungpook National University Medical Center. With the patient under general anesthesia, the lesser curvature and posterior aspect adjacent to the EGJ were meticulously dissected and visualized using a laparoscopic approach. A partially circumferential full-thickness incision at the distal margin of the tumor was then made using an endoscopic approach under laparoscopic guidance. The SMT was resected using laparoscopic ultrasonic shears, and the gastric wall was closed using two-layer suturing. Thereafter, the patency and any leakage were checked through endoscopy. Results: All the ELFR procedures with laparoscopic two-layer suturing were performed successfully without an open conversion. The mean operation time was $139.2{\pm}30.9$ minutes and the blood loss was too minimal to be measured. The tumors from four patients were leiomyomas, while the tumors from the other two patients were gastrointestinal stromal tumors with clear resection margins. All the patients started oral intake on the third postoperative day. There was no morbidity or mortality. The mean hospital stay was $7.7{\pm}0.8$ days. Conclusions: ELFR with laparoscopic two-layer suturing is a safe treatment option for patients with an SMT close to the EGJ, as major resection of the stomach is avoided.

• Current Photovoltaic Research
• /
• v.4 no.3
• /
• pp.108-113
• /
• 2016

III-V compound semiconductor based thin film solar cells promise relatively higher power conversion efficiencies and better device reliability. In general, the thin film III-V solar cells are fabricated by an epitaxial lift-off process, which requires an $Al_xGa_{1-x}As$ ($x{\geq}0.8$) sacrificial layer and an inverted solar cell structure. However, the device performance of the inversely grown solar cell could be degraded due to the different internal diffusion conditions. In this study, InGaP/GaAs double-junction solar cells are inversely grown by MOCVD on GaAs (100) substrates. The thickness of the GaAs base layer is reduced to minimize the thermal budget during the growth. A wide band gap p-AlGaAs/n-InGaP tunnel junction structure is employed to connect the two subcells with minimal electrical loss. The solar cell structures are transferred on to thin metal films formed by Au electroplating. An AlAs layer with a thickness of 20 nm is used as a sacrificial layer, which is removed by a HF:Acetone (1:1) solution during the epitaxial lift-off process. As a result, the flexible InGaP/GaAs solar cell was fabricated successfully with an efficiency of 27.79% under AM1.5G illumination. The efficiency was kept at almost the same value after bending tests of 1,000 cycles with a radius of curvature of 10 mm.