• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.219-232
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• 2023

Mobility services need to change according to the regional characteristics of the target service area. Accordingly, analysis of mobility patterns and characteristics based on Origin-Destination (OD) data that reflect travel behaviors in the target service area is required. However, since conventional methods construct the OD data obtained from the administrative district-based zone system, it is hard to ensure spatial homogeneity. Hence, there are limitations in analyzing the inherent travel patterns of each mobility service, particularly for new mobility service like Demand Responsive Transit (DRT). Unlike the conventional approach, this study applies a data-driven clustering technique to conduct spatial analyses on OD travel patterns of regional mobility services based on reconstructed OD data derived from re-aggregation for original OD distributions. Based on the reconstructed OD data that contains information on the inherent feature vectors of the original OD data, the proposed method enables analysis of the spatial characteristics of regional mobility services, including public transit bus, taxi and DRT.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.282-288
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• 1999

Purpose: A cross-calibration equation is needed to compare bone mineral density measured by different dual X-ray absoptiometry systems. We performed this study to establish appropriate cross-calibration equations between two different dual X-ray absorptiometry systems. Materials and Methods: Bone mineral density of anterior-posterior lumbar spine (L2-4 level) and femoral neck were measured in 109 women ($55{\pm}11yr$) using two different dual X-ray absorptiometry systems (Lunar EXPERT-XL and Hologic QDR 4500-A). Bone mineral density values measured by two systems, including area, bone mass content, bone mineral density and percentile of young normals were compared and cross-calibration equations between two systems derived. Results: The bone mineral density values of 109 women measured by Lunar system were $0.958{\pm}0.17g/cm^2$ at L2-4 and $0.768{\pm}0.131g/cm^2$ at femur neck, which were significantly higher ($13{\pm}6%$ at L2-4 and $19{\pm}7%$ at femur neck, p<0.001) than those ($0.851{\pm}0.144 g/cm^2$ at L2-4 and $0.649{\pm}0.108 g/cm^2$ at femur neck) by Hologic system. Bone mineral content and percentile of young normals measured by Lunar system were also significantly higher than those by Hologic system (p<0.001), whereas there was no difference in area (p>0.05). There was a high correlation between bone mineral density values of L2-4 and femoral neck obtained with both dual X-ray absortiometry systems (r=0.96 and 0.95, respectively). Cross-calibration equations relating the bone mineral density were Lunar= 1.1287${\times}$Hologic -0.0027 for L2-4 and Lunar= 1.1556${\times}$Hologic+0.0182 for femoral neck. Conclusion: We obtained cross-calibration equations of bone mineral density between Lunar EXPERT-XL and Hologic QDR 4500-A. These equations can be useful in comparing bone mineral density obtained by different dual X-ray absorptiometry systems.

• Defense and Technology
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• no.9 s.175
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• pp.46-53
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• 1993

과학기술의 급진적인 발달과 환경보존규제 강화로 자동차의 수명도 그렇지만 항공기의 수명이 20년에서 10년, 앞으로는 더 짧아질지도 모르는 일입니다 빨리 기종을 확정하여 실력을 유감없이 발휘하는 길만이 항공산업을 발전시키는 길이라고 생각됩니다 우리 항공산업의 발자취와 개발의 중요성을 재인식하고, 국민과 호흡을 같이하는 새시대에 걸맞는 발전전략 차원에서, 정부의 구체적인 지원정책을 위시한 자세한 홍보의 필요성과 함께 기종선정이 조속히 마무리 되어야 합니다

• Aerospace Industry
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• v.51
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• pp.38-45
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• 1997

금년 들어 보잉사는 737-700을 2월에 첫비행 시킨데 이어 현재 -800을 6월에 출고할 준비중에 있다. 보잉 737기종이 처음 등장하고부터 30년 가까이 지나는 동안 이른바 737 패밀리는 공전의 매출세를 보여 이제는 20세기 마지막을 장식할 베스트셀러 기종으로 손꼽히게 되었다.

• Journal of Chest Surgery
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• v.24 no.12
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• pp.1225-1227
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• 1991

Pneumomediastinum and subcutaneous emphysema produced by air turbine dental drills, although widely reported in dental publications, are rarely reported in the thoracic journals. We report a case of 38-year-old man with pneumomediastinum and subcutaneous emphysema after use of a air turbine dental drill for dental extraction.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.663-668
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• 2010

Background: Spontaneous pneumomediastinum is an uncommon disorder with few cases reported. It usually occurs in young males and has benign self-limiting course without any apparent concomitant factor. It is seen after intrathoracic pressure changes leading to alveolar rupture. The clinical experiences of two medical centers were reviewed to aid in optimal management. Material and Method: Retrospective review between March 2003 and August 2010 with spontaneous pneumomediastinum patients was performed. Result: 24 patients were identified with a diagnosis of spontaneous pneumomediastinum. These 24 patients were comprised of 18 men and 6 women with mean age 18.9 years (range 10 ~ 33). The major initial complaints were chest pain (79.2%), throat pain (62.5%), and subcutaneous emphysema (41.7%). The triggering events were exercise (16.7%), coughing (12.5%) and vomiting (12.5%). No apparent triggering event was noted in 54.2% of patients. In all cases, chest radiograph and computed tomography was done. Diagnostic computed tomography was required in 25%. White blood cell counts and C-reactive protein (CRP) were checked, and their initial mean values were $9,790{\pm}3,240/{\mu}L$ Land $1.31{\pm}1.71mg/dL$, final mean values were $5,440{\pm}1,665/{\mu}L$ Land $0.72{\pm}0.73mg/dL$, respectively. 23 patients were admitted (average $5.0{\pm}1.8$) and the symptoms were self-limiting in all cases without complications. Conclusion: Spontaneous pneumomediastinum is a benign condition with mild inflammatory signs that often presents with chest or throat pain. Secondary causes must be ruled out to avoid an unfavorable outcome with less invasive study. Because of very rare complications and recurrence, outpatient basis and shortened hospitalization may be feasible.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.506-509
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• 2011

The development of subcutaneous emphysema is a well-known complication that has been reported after dental extraction, endodontic treatment, or restorative preparation. Gaseous invasion, leading to swelling, crepitus on palpation, is commonly restricted to the connective tisssues immediately adjacent to the entry site. However, the use of compressed air- and water-cooled turbines may allow large amounts of air and water to be driven through the fascial planes into the mediastinum, pleural space, or even the retroperitoneum. This case report is about the patient who presented with subcutaneous emphysema that occurred after fracture line inspection. Possible cause, treatment, and prevention of emphysema will be discussed.

• Journal of the military operations research society of Korea
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• v.35 no.1
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• pp.63-82
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• 2009

The purpose of this study is to analyze the problems of current rules and regulations on the source selection for weapon system in defense acquisition project and suggest several techniques to ensure objectivity and fairness. As an application example, Helicopter source selection was presented. It was analyzed and compared through technique application and strength and weakness analysis of AHP, PROMETHEE and Attribute Transformation. The decision making techniques which make all conditions satisfactory in all situations are nonexistent. Thus, it is estimated that we can maintain the objectivity in the source selection of weapon systems by applying suitable decision making techniques in accordance with the patterns of evaluation item.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.519-521
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• 2011

A 1-year-old Goffin cockatoo (Cacatua goffini) presented a soft non-painful and balloon-like mass around the cervical area. Subcutaneous emphysema due to cervicocephalic air sac trauma was diagnosed based on history and physical examination, and was confirmed by radiographic examination. Because the cutaneous tab was unsuccessful, a modified syringe stent was carried out. The bird showed no adverse signs for two weeks after implantation. After surgical removal of the stent, the bird did not reveal subcutaneous emphysema.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.311-317
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• 2023

CT-guided percutaneous transthoracic needle biopsy (PTNB) plays a key role in the diagnosis of pulmonary abnormalities. Although the procedure is considered safe and effective, there exists a potential for complications, such as pneumothorax, hemorrhage, hemoptysis, air embolism, and tumor seeding. However, pneumatoceles after CT-guided PTNB have been rarely reported. Herein, we report two cases of pneumatoceles that developed immediately after PTNB for primary lung cancer. A pneumatocele filled with hematoma should be considered in cases with a newly developed nodule along the needle tract during short-term follow-up CT after PTNB.