• Journal of rehabilitation welfare engineering & assistive technology
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• v.2 no.1
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• pp.27-33
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• 2009

Generally, implantable microphone has been implanted in the temporal bone for implantable middle ear hearing devices (IMEHDs). In this case, the microphone's membrane can be damaged and can be generated biological noise. In order to overcome the these problems, the location of implanted microphone should be changed. As an alternative, the microphone can be implanted in the external auditory canal. However, the sound emission can be produced because of vibration transducer toward reverse direction from the tympanic membrane to the external auditory canal. In this paper, an amount of the emitted sound is measured using a probe microphone as the changing the position of microphone in the external auditory canal of a physical ear model, which is similar to acoustical and vibratory properties of the human ear. Through the measured value, the location of the microphone was assumed in the external auditory canal. According to the analysis, the microphone input sound can be decreased when microphone position become more distance from the tympanic membrane in the auditory canal. However, the external auditory canal is not appropriated to implantable microphone position, because sound emission is not completely eliminated.

• The Journal of the Korean dental association
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• v.47 no.10
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• pp.669-676
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• 2009

Purpose : Anterior region is crucial area for esthetic implant restoration. However, the alveolar process undergoes atrophy after removal of teeth and creates unfavorable situation for implant installation. The knowledge of the thickness of alveolar bone is required to estimate and expect the bone resorption after extraction. The aim of this study is to measure facial, palatal and faciopalatal bone thickness on maxillary anterior teeth. Methods : Facial, palatal, and faciopalatal bone thickness were measured on the computed tomography (CT) images from 57 patients, using an image analyzer program (Ondemand$3D^{(R)}$, Cybermed, Seoul, Korea). Results : The thickness of facial bone in incisors, lateral incisors and canines were less than 1 mm. The thickness of facial bone increased from anterior to posterior region and the thickness of palatal bone increased from posterior to anterior region. Conclusion : The measurement can be used for planning implant surgery before extraction. CT has are clinically useful in the evaluation of thickness of alveolar bone.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.192-198
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• 2007

Kimchi is one of the representative traditional foods in Korea, which is recognized as a kind of wellbeing foodstuffs. However, as increasing foreign-made Kimchi, its safety as food is at the forefront of public health concerns. We analyzed the washing methods of Chinese cabbages, which are the main materials in Kimchi, to prevent parasite contamination during preparing it. To decontaminate parasite eggs from Chinese cabbages, discard the discolored outer leaves from cabbages, spread the space of leaves with fingers and rinse more than 3 separate water tanks with streaming water (velocity more than 0.8m/sec). At each tank, Chinese cabbages were rinsed with more than 3 strokes upward and downward within the streaming water followed by moving back and forth more than 3 times, with 20cm in height and 30cm in width, respectively. Decontamination efficiency increased higher in parallel with streaming velocity of water, and with adding the vegetable detergent to the tank water.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.1
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• pp.17-21
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• 2000

Purpose : Dermatofibrosarcoma protuberans(DFSP) is a rare tumor of the skin with a strong tendency of infiltration to surrounding tissues. Inadequate surgical intervention brings about frequent recurrence and poor prognosis. We attempted to find a guideline for adequate treatment for DFSP. Materials and Methods : Fourteen cases who had been treated in our department since Mar. 1993 and followed up for more than 12 months postoperatively were reviewed. Including nine cases who were transferred from other hospital after recurrence, thirteen cases underwent wide resection. One case was treated by intralesional resection followed by chemotherapy (CYVADIC) due to neurovascular abutment to the mass in the inguinal area. Results : The nine cases who were transferred due to recurrences experienced recurrence in average 1.3(1-2) times and the average period until first local recurrence from primary operation was 11.8(2-24) months. The thirteen cases with wide surgical margin showed no recurrence at the final follow up. One case treated by intralesional resection and chemotherapy showed multiple recurrence and died of the disease due to lung metastasis. Conclusions : From these data, we could find that primary wide resection can be the way of reducing recurrence and metastasis, and the follow up period for the detection of recurrence should be at least two years.

• The Journal of the Korean bone and joint tumor society
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• v.12 no.1
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• pp.30-36
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• 2006

Purpose: Epitheliod sarcoma is an obscure clinical entity. This study analyzes the correlation between the clinical course and the AJCC stage, presence of residual tumor and ezrin-expression. Materials and Methods: Twenty-three cases of epithelioid sarcoma were eligible. All the cases had operation. Fifteen cases had systemic chemotherapy and 6 cases had adjuvant radiotherapy. Immumohistochemical analysis was done for 15 cases. Analyzed factors were initial stage, adjuvant treatment, local recurrence, residual tumor immumohistochemical results and surgical margin. Results: The event free survival rate of 15 stage II, III cases was 47.4% at 129 months. The actual survival rate of 8 stage IV cases was 37.5% at 80 months. The presence of residual tumor tissue on re-excision specimen showed statistical significance on event free survival rate(P=0.03). Adjuvant therapy showed no impact on outcome. The stage IV and locally recurrent cases had a positive relation with Ezrin-positivity. Conclusion: Residual tumor showed correlation in the outcome of epitheliod sarcoma. Chemotherapy and radiation therapy did not affect the outcome. Further case collection and analysis is needed for the significance between Ezrin expression and clinical behavior.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.579-585
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• 2006

Introduction: The fibular free flap is now considered as the first choice for long mandibular discontinuity defect. In spite of its good bone quality for implant installation, its diameter is too narrow to rehabilitate the masticatory function with implant installation. In this report, distraction osteogenesis was used for the augmentation of bone to install the dental implant in the mandible which was reconstructed with a vascularized fibular free flap. Patients and Methods: Three patients undertook the vertical augmentation of grafted fibular bone and dental implants were installed. On the day 8 post-surgery, the activation of the distractor was started at the rate of 1 mm twice a day. The total amount of distraction was 15 mm in two patients and 12.5 mm in one patient. Twelve implants were installed in three patients. Dental implants were simultaneously installed during removal of the distraction device in two patients. In one patient, the implant installation was delayed after device had been removed. All three patients showed the symptoms of mild to severe postoperative infection during the activation and consolidation. However, the distracted site showed undisturbed bone regeneration. Conclusion: The distraction osteogenesis showed the reliable results for the vertical augmentation of fibular bone which was used for the mandibular reconstruction. However, the great tendency of postoperative infection must be considered and clinically controlled.

• The Journal of the Korean bone and joint tumor society
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• v.19 no.2
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• pp.43-49
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• 2013

Purpose: We analyzed the treatment outcomes of patients with sacral giant cell tumor. Materials and Methods: We retrospectively reviewed 7 patients with giant cell tumor of the sacrum who were treated at out institution between 1990 and 2012. Results: There were 2 men and 5 women with mean age of 23.6 years. The average follow up was 52.3 months (range, 15-73 months). Six patients received surgical treatment. Intralesional curettage was performed for the 5 patients and marginal resection for another one patient. The remaining one patient was received radiation only. The patients who received radiation therapy and marginal excision had no residual or recurrent tumors. Of 5 patients with intra-lesional excision, one patient needs one more operation; two patients need two more operation for local control of the giant cell tumor. The remaining two patients failed to gain local control in spite of additional treatments. Conclusion: For the treatment of sacral giant cell tumor, intralesional resection can be one of the treatments option with minimal neurologic injury. Furthermore, radiation therapy can be recommended when complete excision or curettage is impractical.

• Journal of Mushroom
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• v.15 no.4
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• pp.254-258
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• 2017

Mushroom mites have recently caused severe damage to sawdust beds, mushroom mycelia, and fruiting bodies; therefore, they have reduced the production of the button mushroom, Agaricus bisporus, in greenhouses. There are currently no registered pesticides for mushroom mites. It is necessary to selectively control mushroom flies and mites without affecting the growth of the mushroom. We examined biological control of mushroom mites using predatory mite Stratiolaelaps scimitus in button mushroom cultivation. As a result, a three times treatment (1 treatment after water cleaning, 1 treatment after fungus inoculation, and 1 treatment before or after casing) was most effective at controlling mushroom mites, with 3.000 predatory mites (3 bottles) scattered evenly over $165-230m^2$ every 1-2 m. Predatory mite Stratiolaelaps scimitus could control mushroom flies and mites at the same time and could be used at any time during cultivation.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.529-552
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• 2004

We made a robust catalogue of reliable records of meteor showers and storms recorded in Korean, Japanese, and Chinese chronicles. In our new catalogue, there are 35 Korean records, 29 Japanese records, and 93 Chinese records. The temporal frequency distribution of records shows two broad peaks around the 10th and the 16th centuries. We observed that the peak in the 10th century is mainly contributed by the Perseids, while the peak in the 16th century was mainly contributed by the Leonids. We found that the ${\eta}-Aquarids$, the Perseids, the Orionids, and the Leonids have been active during the last two millennia. The oldest record of the ${\eta}-Aquarids$ is that of BC 687 in China, and the oldest record of the Perseids is that of 36 AD. Contrary to previous investigations, there has been no nodal shift of the ${\eta}-Aquarids$ and the Orionids, whose mother comet is the Halley's comet. The oldest record of the Leonids is probably that of 288 AD, instead of 902 AD. We also find some evidence on the existence of a possible shower a-Draconids. We note that our catalogue will be useful to investigate meteor showers.