• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.379-385
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• 2007

관성 센서는 외부 장치의 도움 없이 3차원 공간상에서 움직임 측정이 가능하다. 최근 MEMS 기술의 발달로 소형 저가 관성 센서(가속도 센서 혹은 각속도 센서) 제작이 가능해져 관성 센서를 소형 휴대 기기에 내장하여 사용자의 움직임을 감지하거나 의도 파악하는 연구가 진행되고 있다. 본 연구에서는 관성 센서가 내장된 휴대 기기를 이용하여 3차원 공간상에서 6가지 위치에 따라서 각기 다른 6가지 소리를 발생하는 가상의 멀티 타악기 시스템을 제안한다. 즉, 휴대 기기를 상/하로 흔들면 가상 타악기의 타점 위치에 왔을 때 비트 음을 발생하고, 6개의 다른 위치를 구분하여 다른 타점의 위치에서 휴대 기기를 흔들면 각각 그 위치와 미리 지정된 소리가 발생하도록 하였다. 이러한 가상의 멀티 타악기 시스템을 위해서 3차원 공간상에서 실시간으로 사용자의 움직임을 감지하고 휴대 기기의 위치를 파악하는 것이 필요하다. 저가의 관성 센서를 이용하여 사용자가 휴대 기기를 움직이는 동작이 있는 상황에서 실시간으로 휴대 기기의 위치를 추정하는 것은 쉽지 않지만 본 연구에서는 다양한 사용자의 움직임 동작 분석을 통하여 사용자가 가상의 멀티 타악기를 상/하로 흔드는 동작을 감지하고 다른 위치로 이동하는 동작을 구분하였다. 개발된 동작 감지 알고리즘과 위치 구분 알고리즘을 휴대 기기에 적용되어 실제로 가상의 타악기 시스템을 구현하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.7
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• pp.775-782
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• 2008

In this study, ground vibrations and aero space noises that is produced by the PRD(percussion rotary drill) were analyzed by work processes. Ground vibration equations were suggested by $2.798(SD)^{-0.793}$, $3.485(SD)^{-0.793}$, $3.705(SD)^{-0.793}$, according to experiment result, and these equations have reliability of 50%, 90%, 95%, respectively. Ground vibration values by the PRD method correspond to level of $5{\sim}34%$ of values that are assumed by the Attewell & Farmer's equation, and these result compares in reliability 50%. Also, those values were analyzed that correspond to level of $12{\sim}26%$ of ground vibration values by the Prof. Park etc.'s equations. But, the aero space noise was evaluated that is assumed by 88.9 dB(A) at separated distance 50m and is not satisfied even 85dB(A) that is the most negative noise value that present in domestic noise standard. The PRD method was analyzed that noise decrease effect exists hardly comparing with general pile driving method of construction. When is based in these results, the PRD method is judged that it is desirable that classify by the Low-vibration method more than the Non-violation noise method.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.394-398
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• 2013

An 3-year-old female Thoroughbred horse was referred with moderate lameness (3/5G) and mild heat on right hoof of forelimb. She was diagnosed with white line disease (WLD) that was included hoof wall separation by radiographic examination and hoof percussion. Treatment was carried out hoof wall resection at first, followed by disinfection of affected hoof and shod modified heart bar. On the re-examination after 4 months, we could find a results which had no lameness, gas pocket in the white line and clinical signs was improved. Subsequently, she was trained and raced after 8 months of diagnosis. So, we supposed that resection of wall and therapeutic shoeing was good for WLD including hoof separation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.3
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• pp.144-147
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• 2013

Damage to adjacent teeth is one of the various complications that may occur during implant placement and is often the result of improper direction during fixture placement or excessive depth of placement. In general, if detrimental symptoms, such as reaction to percussion in damaged teeth, mobility, and pulp necrosis, are not present, osseointegration should be observed at follow-up. In three cases, the possibility of root damage due to an implant fixture placed too close to each adjacent tooth was perceived on radiographs. However, in all of these cases, there were no clinical symptoms or radiographic changes present in the tooth, and the implants did not exhibit decreased stability or peri-implantitis. Therefore, we can carefully predict that the implant fixture close to the adjacent tooth did not invade the cementum of the root, and therefore did not produce the suspected pulpal damage or periradicular symptoms. In this study, we considered both the implant status as well as the adjacent tooth.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.383-388
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• 2001

Effects of particle property variation of cone crack shape according to impact velocity in silicon carbide materials were investigated. The damage induced by spherical impact having different material and size was different according to materials. The size of ring cracks induced on the surface of specimen increased with increase of impact velocity within elastic contact conditions. The impact of steel particle produced larger ring cracks than that of SiC particle. In case of high impact velocity, the impact of SiC particle produced radial cracks by the elastic-plastic deformation at impact regions. Also percussion cone was formed from the back surface of specimen when particle size become large and its impact velocity exceeded a critical value. Increasing impact velocity, zenithal angle of cone cracks in SiC material was linearly decreasing not effect of impact particle size. An empirical equation, $\theta=\theta_{st}-\upsilon_p(180-\theta_{st})(\rho_p/\rho_s)^{1/2}/415$, was obtained from the test data as a function of quasi-static zenithal angle of cone crack($\theta_{st}$), the density of impact particle(${\rho}_p$) and specimen(${\rho}_s$). Applying this equation to the another materials, the variation of zenithal angle of cone crack could be predicted from the particle impact velocity.

• Journal of Korean Physical Therapy Science
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• v.5 no.4
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• pp.831-836
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• 1998

Object: We evaluated the efficacy of chest physical therapy in pediatric patients with pneumonia. Method: Retrospective study was performed in 89 pneumonia patients admitted to pediatric unit. The subjects were divided into two groups: control group; treatment group. Control group included 42 patients who didn't receive chest physical therapy. Treatment group included 47 patients who received chest physical therapy. The chest physcial therapy employed were postural drainage, chest percussion, deep breathing training and enhancement of coughings. The efficacy was evaluated by x-ray outcome before discharge. Results: There were no significant difference in age, sex, type of pneumonia, and symptom duration between two groups. However the duration of fever after admission, duration of antibiotic use and hospital stay were longer in treatment group. In treatment group, longer the day to initiate chest physical therapy, longer the hospital stay. The final outcome was not different between groups. Conclusion: The results suggest that the referred patients for chest physical therapy tends to be of severe cases. Nevertheless, the result that the outcome was not different in two groups means that the chest physical therapy could be used as a effective treatment method in pediatric patient with pneumonia.

• Journal of Chest Surgery
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• v.14 no.2
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• pp.140-143
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• 1981

Thymolipoma is extremely uncommon benign mediastinal tumor consisting of fatty and thymic tissue. Only 50 verified cases have been reported in the world literatures. This one case is the first reported example of surgically treated thymolipoma associated with spontaneous pneumothorax. A thirty-two year old male patient had been in good health until two days prior to admission, when he noted sudden dyspnea associated with an aching pain over the left precordium. The dyspnea and chest pain had become progressively worse. The physical examination revealed that left hemithorax was tympanic sound on percussion and absence of breathing sound on auscultation and point of maximal impulse was located on the 4th intercostal space at the left sternal border. Emergency closed thoracostomy was performed under the impression of tension type spontaneous pneumothorax of the left lung. After closed thoracostomy, point of maximal impulse was not changed inspire of full expansion of the left lung and chest X-ray was strongly suggested pericardial effusion or cardiomegaly which couldn`t account for by clinical course and hemodynamic evidence. EKG, echocardiogram, bronchofiberoscophy, bronchogram and diagnostic thoracentesis was performed. On Dec. 8, 1980, operation was performed under the impression of mediastinal tumor in the anterior mediastinum. At left posterolateral thoractomy, a large fatty mass, measuring 35 x 27 x 13 Cm in dimension and weighing 3350 gm, was resected and multiple bullae on the apicoposterior segment of the left upper lobe was resected and continuously sutured. The pathologic diagnosis of the fatty mass was thymolipoma. The postoperative course was uneventful and discharged in good general conditions.

• Journal of Chest Surgery
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• v.14 no.2
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• pp.135-139
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• 1981

Thymolipoma is extremely uncommon benign mediastinal tumor consisting of fatty and thymic tissue. Only 50 verified cases have been reported in the world literatures. This one case is the first reported example of surgically treated thymolipoma associated with spontaneous pneumothorax. A thirty-two year old male patient had been in good health until two days prior to admission, when he noted sudden dyspnea associated with an aching pain over the left precordium. The dyspnea and chest pain had become progressively worse. The physical examination revealed that left hemithorax was tympanic sound on percussion and absence of breathing sound on auscultation and point of maximal impulse was located on the 4th intercostal space at the left sternal border. Emergency closed thoracostomy was performed under the impression of tension type spontaneous pneumothorax of the left lung. After closed thoracostomy, point of maximal impulse was not changed inspire of full expansion of the left lung and chest X-ray was strongly suggested pericardial effusion or cardiomegaly which couldn`t account for by clinical course and hemodynamic evidence. EKG, echocardiogram, bronchofiberoscophy, bronchogram and diagnostic thoracentesis was performed. On Dec. 8, 1980, operation was performed under the impression of mediastinal tumor in the anterior mediastinum. At left posterolateral thoractomy, a large fatty mass, measuring 35 x 27 x 13 Cm in dimension and weighing 3350 gm, was resected and multiple bullae on the apicoposterior segment of the left upper lobe was resected and continuously sutured. The pathologic diagnosis of the fatty mass was thymolipoma. The postoperative course was uneventful and discharged in good general conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.1
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• pp.73-79
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• 2000

A material of 48 patients with 60 avulsed and replanted permanent teeth were followed retrospectively in the period of 1996. 1 to 1998. 12 (mean observation period=1year 7months). The age of the patients at the time of replantation ranged from 9 to 63 years (mean=24 years). Clinical records of patients were reviewed to obtain valid data concerning the extent of injury and treatment provided. Pulpal and periodontal healing states were examined with periapical x-rays and clinical examination procedures (i.e. percussion test and mobility test) at their recall visit. Root ankylosis was found in fifty-two teeth(87%) and root resorption in twenty-four(40%). Only two of the replanted teeth(3%) showed partial regeneration of the periodontal ligament. Six teeth(10%) resulted in tooth loss, but the remaining fifty-four were clinically well functioning. Most of teeth have mild marginal bone loss accompanied by gingival retraction without pathological periodontal pockets. The incidence of root resorption was much higher in younger age group. However, it was not affected by the interval between avulsion and replantation, the condition of supporting tissues, the degree of root formation and the type of splinting, indicating that multiple factors involved in determining the prognosis of replanted teeth. Based on these findings, avulsed teeth in unfavorable conditions (i.e. long extra-alveolar periods, etc.) should be preserved if possible.

• Journal of the Korean Society of Safety
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• v.26 no.1
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• pp.8-14
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• 2011

Noise and vibration are likely to disturb the sensory system of human body leading to psychological stress and thereby property damage. In this research, a cut out switch(COS) with a built-in acoustic absorber along with a COS fuse broken was developed to reduce percussion noise. This new system is based on a design approach that combines existing absorber systems: expansion type, resonator type, and acoustic absorber type silencer The noise performance of the new system was simulated using the $SYSNOISE^{TM}$ software under optimized parameters: the diameter of perforated plate 2 mm, the plate thickness 3 mm, the width of expansion room 25 mm, the impinging vortex room 14 mm, and the noise absorbtion room 10 mm. The results showed that it reduced noise by approximately 41.1 dB compared to the current systems available in the market. Furthermore, it showed reduced noise by approximately 12 dB more than a product with an acoustic absorber of the Fault Tamer(USA).