• The Journal of the Korean bone and joint tumor society
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• v.13 no.1
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• pp.14-21
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• 2007

Bone is a common site for metastatic spread from many kinds of malignancies. The morbidity associated with this metastatic spread can be significant, including severe pain. When it comes to spinal metastasis, occupying nearly 40% of skeletal metastases, the risks of complications, such as vertebral body collapse, nerve root impingement, or spinal cord compression, are also significant. Because of the necessity of preserving the integrity of the spinal column and the proximity of critical structures, surgical treatment has limitations when durable local control is desired. Radiotherapy, therefore, is often used as an adjunct treatment or as a sole treatment. A considerable limitation of standard radiotherapy is the reported recurrence rate or ineffective palliation of pain, either clinically or symptomatically. This may be due to limited radiation doses to tumor itself because of the proximity of critical structures. CyberKnife is an image-guided robotic radiosurgical system. The image guidance system includes a kilovoltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator (6 MV) mounted on a robotic arm. Highly conformal fields and hypofractionated radiotherapy schedules are increasingly being used as a means to achieve biologic dose escalation for body tumors. Therefore, we can give much higher doses to the targeted tumor volume with minimizing doses to the surrounding critical structures, resulting in more effective local control and less severe side effects, compared to conventional fractionated radiotherapy. A description of this technology and a review of clinical applications to bone metastases are detailed herein.

• Strategy21
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• s.38
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• pp.13-46
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• 2015

Dokdo issue reaches beyond economic and security interest to Koreans, as it is regarded as symbol of her independence. Albeit the fact that Japan has merely no legitimate title over Dokdo, Japan has been tenaciously insisting their jurisdiction over Dokdo since the independence of Korea. Under such circumstances, public outrage towards Japan is most certainly understandable. Yet, mere outrage itself, lacking in logic and factual grounds, can contribute little if not any, to the desirable solution of the problem. Precedents reveal that dealing maritime issues amid lack of profound understanding in international law has often led to undesirable results, such as the inclusion of Dokdo in the Joint Management Fisheries Zone in 1999 Korea-Japan Fisheries Agreement. In a sense, adroit use of international law is a critical element in preserving Korea's sovereign rights against persistent Japanese plans to rob Dokdo once again. The Dokdo issue is inextricably bound to international law; the legal status of Dokdo as island, the equitable solution of maritime boundary delimitation and effective control, existence of dispute. Yet, the public policies and arguments made by pundits are generally in lack of understanding in international law. It is now the time for Korea to commence on long-term cross-academia / department plans to establish Dokdo strategy as part of the nationwide maritime strategy effectively using international law as its stronghold.

• Korean Journal of Materials Research
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• v.24 no.9
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• pp.495-501
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• 2014

Despite having many attractive properties, $ZrO_2$ ceramic has a low fracture toughness which limits its wide application. One of the most obvious tactics to improve its mechanical properties has been to add a reinforcing agent to formulate a nanostructured composite material. Nanopowders of $ZrO_2$ and Cr were synthesized from $CrO_3$ and Zr powder by high energy ball milling for 10 h. Dense nanocrystalline $2/3Cr-ZrO_2$ composite was consolidated by a high-frequency induction heated sintering method within 5 min at $600^{\circ}C$ from mechanically synthesized powder. The method was found to enable not only rapid densification but also the inhibition of grain growth, preserving the nano-scale microstructure. Highly dense $2/3Cr-ZrO_2$ composite with relative density of up to 99.5% was produced under simultaneous application of a 1 GPa pressure and the induced current. The hardness and fracture toughness of the composite were 534 kg/mm2 and $7MPa{\cdot}m1/2$, respectively. The composite was determined to have good biocompatibility.

• Korean Journal of Computational Design and Engineering
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• v.17 no.6
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• pp.443-455
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• 2012

The configuration of a musculoskeletal (MS) system is closely related to the individual motions of the human body. Many researches have been focused on evaluating the associations between the MS configuration and the individual motion using patient-specific MS models, but it still remains a challenging issue to accurately predict the motion by differed configurations of the MS system. The main objective of this paper is to predict the changes of a patient-specific gait by altering the geometric parameters of the hip joint using function-based morphing method (FBM). FBM is suitable for motion analysis since this method provide a robust way to morph a MS model while preserving the biomechanical functions of the bones. Computed-muscle control technique is used to calculate the muscle excitations to reproduce the targeted motion within a digital MS model without the motion-captured data. We applied this approach to a patient who has an abnormal gait pattern. Results showed that the femoral neck length and the angle significantly affect to the motion especially for the hip abduction angle during gait, and that this approach is suitable for gait prediction.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.88-93
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• 1996

Neurilemmomas are the most common benign tumor of the peripheral nerve trunks, and arises from the cells in the sheath of Schwann. Neurilemmomas are well encapsulated and may be separated easily from surrounding tissue and lie completely within a larger nerve trunk, with bundles of neurofibrils spread out over the surface of the tumor. A careful dissection and retraction of the nerve bundles will allow the tumor to be enucleated from the parent nerve without any significant interference with the function of the nerve. Resection of the involved nerve is seldom necessary and should be avoided if at all possible. Our aim in microscopic excision of neurilemmoma of extremities is to reduce any disturbance of the intact neurofibrils of the parent nerve. Thirteen cases of neurilimmomas were treated by microscopic excision at the Department of Orthopaedic Surgery, Korea University Hospital between January 1990 and March 1995. The results was as follows ; 1. The average age at surgical intervention was 40.1 years. Cases in fourth and fifth decades predominated. 2. In their anatomical distribution, 8 cases were in the upper extremity and 5 cases in the lower extremity. 11 cases were on the flexor surface. 3. On the operative field, all the tumors were well encapsulated, however 1 case of 13 was adherent to the periosteum of fibula. 4. In all cases, the tumor were enucleated from the parent nerve without any injury to nerve under high-power magnification, preserving individual fascicles, and sensory and motor function.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.107-113
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• 1986

It is estimated that the loss of Korean agricultural and fishery products during the storage period is usually more than 20%, and it is difficult to increase agricultural products by a 10% annual rate directly. Therefore, development of food preservation techniques has now become a most important atternative for the indirect increase of such products and for its senitary distribution. Changes eating habits and improved living conditions have accelerated the demand for convenience food production and for this reason it is essential that raw materials at stable, resonable prices and hygienic quality be available the year round. At the end of 1980, the Korean government conceded th economical feasibility of the storage of foods by irradiation and a procedure for preserving food by irradiation on a batch scale was successfully developed by KAERI in 1982. Based on the research results accomplished by the KAERI and on the recommendation on wholesomeness of irradiated food by Joint Committee of FAO/IAEA/WHO in 1980, the approval of wholesomeness of irradiated food was declared by presidential decree in June 1985 and the procedure of permission for individual items is in progress. Korean private firms (Ryung Young Co.) which was technically assisted by KAERI for five years have taken mush interest in the establishment of such facilities in Korea, therefore Ryung Young Co. had proposed for the construction of 500 Kci Co-60 irradiator to the Ministry of Science and Technology in July 1984. The permission of construction has approved by government in May 1985. The commercial irradiator will be constructed as one of the most modernized facilities until May 1987 and that facilities will contribute the propagation of commercial storage of foods and its hygienic quality.

• Journal of the Korea Computer Graphics Society
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• v.5 no.2
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• pp.33-41
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• 1999

This paper presents a new algorithm about motion adjustment for dynamic balance. It adjusts an unbalanced motion to an balanced motion while preserving the nuance of original motion. We solve dynamic balancing problem using the zero moment point (ZMP) which is often used for controlling the balance of biped robot. Our algorithm is consists of four steps. First, it fits joint angle data to spline curves for reducing noise. Second, the algorithm analyzes the ZMP trajectory so that it can detects the dynamically-unbalanced duration. Third, the algorithm project the ZMP trajectory into the supporting area if the trajectory deviates from the area. Finally, the algorithm produces the balanced motion that satisfies the new ZMP trajectory. In this step, the constrained optimization method is used so that the new motion keeps the original motion characteristics as much as possible. We make several experiments in order to prove that our algorithm is useful to add physical realism to a kinematically edited motion.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.125-131
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• 2011

Optimal treatment of the torn posterior cruciate ligament (PCL) remains controversial. The type of tibial fixation (transtibial vs inlay), the femoral tunnel position within the femoral footprint (central, eccentric or isometric), and the number of bundles in the reconstruction (single-bundle vs double-bundle) are controversial issues. The PCL has a better chance of spontaneously healing than the anterior cruciate ligament (ACL) because of a rich blood supply (near the branch of the middle genicular artery) and coverage with a thicker synovium. In general, for easier passage of the graft and full visualization of the original ligament attachment site during the precise positioning of the tunnel, the remaining PCL fibers are usually debrided during reconstruction. However, the remaining remnant structures would significantly contribute to the posterior stability of the knee joint, the healing of the graft, preserving proprioceptive function of the mechanoreceptors in the PCL. Double bundle PCL reconstruction may result in some surgical complications because of increased complexity of making tunnel. Therefore, single bundle PCL reconstruction with remnant preservation seems to be an effective procedure.

• The Journal of the Korea Contents Association
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• v.6 no.9
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• pp.19-27
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• 2006

Mean shift procedure is applied for the data points in the joint spatial-range domain and achieves a high quality. However, a color image is segmented differently according to the inputted spatial parameter or range parameter and the demerit is that the image is broken into many small regions in case of the small parameter. In this paper, to improve this demerit, we propose the method that groups similar regions using region merging method for over-segmented images. The proposed method converts a over-segmented image in RGB color space into in HSI color space and merges similar regions by hue information. Here, to preserve edge information, the region merge constraints are used to decide whether regions are merged or not. After then, we merge the regions in RGB color space for non-processed regions in HSI color space. Experimental results show the superiority in region's segmentation results.

• Journal of Korean society of Dental Hygiene
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• v.7 no.2
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• pp.153-166
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• 2007

The job of dental hygienists is specialized, and they have to be capable of performing their primary duties including prevention of oral diseases, oral prophylaxis, and oral health education. To ensure their successful job performance, dentists should have an accurate understanding of their duties and need a change of mind-set about them. And there should be written legal and concrete regulations on the coverage of their work in order to let them boost their job performance with pride and a sense of responsibility. The purpose of this study was to examine the actual roles and job performance of dental hygienists in clinical field in an attempt to discuss the substantial job performance of dental hygienists and their job enlargement. It's basically meant to help enhance the efficiency and quality of medical services. The subjects in this study were 471 dental hygienists in dental clinics, dental hospitals, university hospitals and general hospitals across the nation, on whom a survey was conducted in person from March 2 to 25, 2005. The collected data were analyzed with SPSS Win 12.0 program, and the findings of the study were as follows: 1. The major jobs they currently performed included oral health education, hospital management, simple duties, extensive dental hygiene duties and joint treatment assistance. They hoped to continue to be responsible for oral health education, preventive treatment and extensive dental hygiene duties. 2. As for their current job by age, extensive dental hygiene duties, preventive treatment, joint treatment assistance, preserving treatment, prosthetic treatment and pediatric treatment were most conducted by the dental hygienists who were at the age of 26 to less than 31, and those who were at the age of 31 and up were most responsible for hospital management and simple duties. 3. As to job awareness by workplace, their workload was statistically significantly different according to their workplace. The hospital employees took care of more work than those in clinics. 4. Concerning job awareness by age, the younger dental hygienists suffered more role conflicts and were given a less free hand in work handling, the middle-aged group's job was uncertain. Legal regulations about the coverage of their work should be prepared in detail as a measure to stir up their responsible job performance and pride. In order to take advantage of experienced dental hygienists, their duties should be more differentiated and specialized, and their working conditions should be improved to boost their job satisfaction. That is, they should be given ample chances for promotion and serving as a middle manager and be given fair treatment according to their career. If their work is accurately darified and specialized based on career, it will boost the efficiency of dental treatment. Dental hygienists also should direct sustained efforts into self-development in order to become a skilled and professional oral health personnel.