• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.104-110
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• 2009

Purpose: Compared to soft tissue sarcoma, the relative risk of extraskeletal osteosarcoma is still not clear. The purpose of this study is to identify the difference in survival and local recurrence rate between two soft tissue sarcomas. Materials and Methods: Twelve patients with pathologically confirmed extraskeletal osteosarcoma were analysed. For retrospective matched case-control study, we selected 72 patients who were confirmed as high grade soft tissue sarcoma and had similar tumor location, tumor size and age to extraskeletal osteosarcoma. Results: Median age was 50 years old. Five cases were located in upper extremity, four in the buttocks, three in the lower extremity. Overall survival rate of extraskeletal osteosarcoma group and high grade soft tissue sarcoma group at 5 years were 52% and 55%. There is no significant difference (p=0.8). Local recurrence rate and metastasis rate were 58%, 67% in extraskeletal osteosarcoma group and 36%, 51% in soft tissue sarcoma group, which were not stastistically significant(p=0.2, p=0.4). Conclusion: Extraskeletal osteosarcoma have similar local recurrence, metastasis and survival rate compare to high grade soft tissue sarcoma. The number of patients of this study were too small to identify outcome of extraskeletal osteosarcoma. Further multi-institutional study should be attempted.

• Journal of the Korean Society of Food Culture
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• v.8 no.3
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• pp.275-287
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• 1993

An ecological survey of food and nutrition was conducted in April and May, among 278 children, 6 to 12 years old, of the Youido elementary school, which offers no school lunch program, and is situated in Youido delta of Han River side of Seoul, known as the location of one of the socioeconomically high groups; Eighteen percent and 18.3% of subjects were proven to be overweight and obese, respectively. With regard to frequency of skipping breakfast, 28.4% of the subjects skipped breakfast often and 2.5% of subjects skipped breakfast every morning. Obese children showed good appetite and the time consumed for eating was shorter than those of normal or overweight children. Most serious anxiety among the mothers for those children was food habit of `eating rapidly' and `overeating'. Another striking observation was that 14.4% of the subjects ate only one side-dish with boiled rice, and such a pattern was more often found in the normal or slim group. Most of the subjects had their snacks after being back in home from school. Thirty-one percent of the children had snacks when they felt hungry, 69% had snacks for various reasons such as `habitually', `for unwinding', and `mother gives me snacks'. Thirty-eight percent of the boys and 19% of the girls had physical exercise everyday and overweight and obese children got exercise more frequently. But the time consumed for exercise was much more shorter than that of normal subjects. Most of the children liked fruits, meats, and biscuit, in contrast, lowest preferency was for vegetables, fermented fish products, and boiled rice mixed with other grains. Obese children experienced more kinds of food than normal or slim group. The study found that habits of overeating due to good appetite and eating rapidly were recognized as one of dominant reasons causing obesity among children. On the other hand, serious dietary problem of children of normal or slim group was eating less variety of food. Active nutrition education for both children and mothers will be recommended with joint participation of teachers.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.4
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• pp.327-343
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• 2004

During tunnel construction, ground failures often occur due to existence of weak zones, such as faults, joints, and cavities, ahead of tunnel face. It is hard to detect effectively weak zones, which can lead underground structure to fail after excavation and before supporting, by using conventional characterization methods. In this study, an enhanced analytical method of predicting weak zones ahead of tunnel face is developed to overcome some problems in the conventional geophysical exploration methods. The analytical method is based on Coulomb's and Gauss' laws with considering the characteristics of electric fields subjected to rock mass. Using the developed method, closed form solutions are obtained to detect a spherical shaped zone and an oriented fault ahead of tunnel face respectively. The analytical results suggest that the presence of weak zones and their sizes, location, and states can be accurately predicted by combining a proper inversion process with resistance measured from several electrodes on the tunnel face. It appears that the skin depth or resistivity in rock mass is affected by the diameter of tunnel face, natural electric potential and noises induced by experimental measurement and spatial distribution of uncertain properties. The developed analytical solution is verified through experimental tests. About 1800 concrete blocks of 5cm by 5cm by 5cm in size are prepared and used to model a joint rock mass around tunnel face. Weak zones are simulated ahead of tunnel face with a material which has relatively higher conductivity than concrete blocks. Experimental results on the model test show a good agreement with analytical results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.278-284
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• 2017

In this study, the heat input conditions suitable for the AZ61 magnesium alloy were derived by controlling the welding speed at a constant rotational speed. In addition, from an economic point of view, industry demands higher welding speeds. Therefore,the effects of the welding speed were studied. The rotational speed applied was 800rpm, and the welding speed was varied from 100 to 500mm/min to evaluate the behavior of the welded regions. Tensile and hardness tests were conducted to examine the mechanical properties. Optical microscopy was used to observe the microstructure and soundness of the welded regions. Defects were observed at the welded region when the welding speed was more than400mm/min. As the welding speed increased, the grain size of the stir zone decreased and the hardness tended to increase proportionally. When the rotational speed was 800 rpm and the welding speed was 200mm/min and 300mm/min, there wereno defects in the welded region and excellent mechanical properties were recorded. In addition, the joint efficiencies were 100.5% and 101.2%, respectively, and the ultimate tensile strength was similar to that of the base metal. Fracture of the tensile specimen occurred between the advancing side and stir zone, and the fracture location coincided with the region where the hardness decreased temporarily.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.81-91
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• 2011

This study was conducted to evaluate the necessity of the anchor lug system in continuously reinforced concrete pavement(CRCP) by comparing longitudinal displacements of CRCPs with and without anchor lugs, and to investigate the effect of horizontal cracking on CRCP performance by measuring the vertical displacements. The measurements before and after the anchor lug section was separated were conducted for 12 days in June, and for 14 days in August after the abrupt displacements according to cutting disappeared, respectively. This short term measurement results showed that when anchor lugs were installed, a daily displacement variation at any location was less than 0.1mm; therefore, longitudinal movements were negligibly small. When there were no anchor lugs, longitudinal displacements mainly occurred near the free end and the displacement variation was small; therefore, an expansion joint system seems to be employed at a CRCP terminus without installing anchor lugs. However, further studies are needed to verify the terminus behavior due to annual temperature changes. The horizontal crack width variation was ignorable and did not affect the vertical displacement of the slab. Therefore, the horizontal crack did not delaminate the slab and did not seem to reduce the structural capacity and performance of CRCP.

• The Journal of the Korean bone and joint tumor society
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• v.18 no.2
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• pp.72-77
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• 2012

Purpose: Unplanned excision of a soft tissue sarcoma is defined as the operation performed for gross removal of a soft tissue sarcoma without regard for preoperative imaging or the necessity to removal a margin of normal tissue covering the cancer. We report our experience of treating primary soft tissue sarcoma after an unplanned excision. Materials and Methods: We retrospectively reviewed 31 patients referred to our hospital after unplanned excision at other hospitals for treatment of a STS. The clinical information was reviewed with a focus on the patient's age, gender, tumor location, tumor size, tumor depth, presumptive diagnoses at the previous surgery, refer hospital, definitive diagnosis, interval between the initial and additional surgery and local recurrence. Results: There were 19 males and 12 females with a median age of 48 years (range, 17-75 years) at the time of referral. Seventeen patients (54.8%) had tumors in their lower limb, 6 (19.4%) had tumors in their upper limb, and 8 (25.8%) had tumors in their trunk. Tumor depth could be determined for 8 patients (25.8%), with superficial and 22 deep tumors (71%). The medial interval between unplanned excision to re-excision ranged from 2 weeks to 1 year (median, 5 weeks). Local recurrence was detected in 2 patients. All patients were alive without metastasis at last follow up. Conclusion: Even in upper class general hospital, many unplanned excision had been performed, which is considered to be avoided. When the relatively huge mass located in deeper layer it requires enough preoperative imaging studies and biopsy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.439-447
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• 2011

Introduction: In today's society, the rapid and appropriate care of the dental emergency patients is much more important. So, a retrospective study on the characteristics of emergency dental injuries and diseases will be very meaningful. Materials and Methods: This retrospective clinical study was carried by reviewing the radiographic films and emergency chart of 11,493 patients who had visited the emergency room of Hallym Sacred heart Hospital and were treated in the Department of Oral and Maxillofacial Surgery from January 2006 to December 2010. Results: The male to female ratio was 1.9:1. The highest monthly incidence was observed in May (10.4%) and June (8.9%) and the peak age distribution was the first decade (56.0%), followed by the second decade (16.0%). Trauma was the most common cause in dental emergency patients, followed in order by toothache, odontogenic infection, temporomandibular joint (TMJ) disorder and oral hemorrhage. Soft tissue injury was most prevalent in the trauma group, followed by tooth injury and facial bone fractures. In the tooth injury group, tooth fracture (56.7%) showed the highest incidence followed in order by tooth subluxation (18.2%), tooth concussion (16.9%), tooth avulsion (11.5%) and alveolar bone fractures (3.7%). In the facial bone fracture group, mandibular fractures (81.8%) showed the highest incidence followed in order by maxilla fractures (15.7%), nasal bone fractures (9.0%), zygomaticomaxillary complex fractures (5.4%), orbital bone fractures (2.5%). In mandibular bone fractures, the most common location was the symphysis (70.1%), followed in order by the mandibular angle (33.0%), mandibular condyle (22.8%) and mandibular body (13.6%). In the infection group, a submandibular space abscess (46.2%) was most common followed in order by a buccal space abscess (17.4%), canine space abscess (16.9%) and submental space abscess (12.3%). TMJ dislocation (89.3%) showed the highest incidence in the TMJ disorder group, followed by TMJ derangement (10.7%). In the other group, a range of specific symptoms due to post operation complications, trigeminal neuralgia, chemical burns and foreign body aspiration were reported. Conclusion: For the rapid and appropriate care of the dental emergency patients, well-organized system should be presented in oral and maxillofacial surgery. And it is possible under analysis of pattern and the variation of the dental emergency patients.

• Design & Manufacturing
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• v.14 no.1
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• pp.8-14
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• 2020

In general, auto parts production assembly line is assembled and produced by automatic mounting by an automated robot. In such a production site, quality problems such as misalignment of parts (doors, trunks, roofs, etc.) to be assembled with the vehicle body or collision between assembly robots and components are often caused. In order to solve such a problem, the quality of parts is manually inspected by using mechanical jig devices outside the automated production line. Automotive inspection technology is the most commonly used field of vision, which includes surface inspection such as mounting hole spacing and defect detection, body panel dents and bends. It is used for guiding, providing location information to the robot controller to adjust the robot's path to improve process productivity and manufacturing flexibility. The most difficult weighing and measuring technology is to calibrate the surface analysis and position and characteristics between parts by storing images of the part to be measured that enters the camera's field of view mounted on the side or top of the part. The problem of the machine vision device applied to the automobile production line is that the lighting conditions inside the factory are severely changed due to various weather changes such as morning-evening, rainy days and sunny days through the exterior window of the assembly production plant. In addition, since the material of the vehicle body parts is a steel sheet, the reflection of light is very severe, which causes a problem in that the quality of the captured image is greatly changed even with a small light change. In this study, the distance between the car body and the door part and the door are acquired by the measuring device combining the laser slit light source and the LED pattern light source. The result is transferred to the joint robot for assembling parts at the optimum position between parts, and the assembly is done at the optimal position by changing the angle and step.

• The Journal of the Korean bone and joint tumor society
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• v.19 no.1
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• pp.14-19
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• 2013

Purpose: We analyzed the oncologic characteristics and outcome of patients with inflammatory myofibroblastic tumor of extremities. Materials and Methods: Among the soft tissue tumor patients who were treated between 1999 and 2012, 5 patients who were pathologically confirmed as the inflammatory myofibroblastic tumor of extremities were analyzed retrospectively. Results: There were 1 man and 4 women with mean age of 44 years (37-55 years). The average follow up was 34.6 months (8-87 months). All patients underwent surgical treatment. Only 1 patient had wide resection margin and remaining 4 had marginal (3) or intralesional (1) resection margin. All of 4 patients without wide resection margin developed local recurrence at 10.3 months (8-19 months). Malignant transformation to fibrosarcoma was occurred in 2 patients who developed local recurrence, and 1 patient developed multiple metastases to lung, liver and lymph nodes and expired at 37 months. Three of 5 patients had tumor location abutted to or invasion to major arteries and 1 patient had tumor invading sciatic nerve. Conclusion: It is observed that inflammatory myofibroblastic tumor of extremities is usually located near the major neurovascular structure. Wide resection should be considered as the initial surgical treatment because this tumor showed a high local recurrence rate and possibility of malignant transformation.

• Journal of the Korean Arthroscopy Society
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• v.10 no.2
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• pp.214-218
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• 2006

Purpose: We describe a new technique of arthroscopic medial plication using pull-out suture with consideration of anatomical location of medial patellofemoral ligament for the treatment of acute or recurrent patellar dislocation. Operative technique: Under arthroscopic examination, sutures are passed through the medial capsule, at which medial patellofemoral ligament is located, from outside to inside of knee joint. Three guide wires are inserted from anterior surface of the patella to upper half of its medial border. Intraarticular portions of sutures are pulled out toward anterior surface of the patella through bony tunnels. Under appropriate tension, the sutures are tied after performing lateral retinacular release. Conclusion: As suturing medial patellofemoral ligament, this technique can maximize the effect of medial plication and can correct subluxation and tilt of the patella. It seems to be a minimally invasive, easy and effective method for the treatment of acute or recurrent patellar dislocation.