• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.319-321
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• 2004

The average glandular dose (AGD) is determined by the breast entrance skin exposure, x-ray tube target material, beam quality (half-value layer), breast thickness, and breast composition. Almost breast cancer always arises in glandular breast tissue. As a result, the average radiation absorbed dose to glandular tissue is the preferred measure of the radiation risk associated with mammography. If the normalized average glandular dose is known, the average glandular dose can be computed from the product of the normalized average glandular dose and breast entrance skin exposure. In this study, AGD was calculated by the breast thickness and various x-ray energy (HVL) in 50% glandular 50% adipose breast by Mo.-Rh. assembly. AGD is 84 mrad in compressed 5 cm breast. These results show that as increasing the breast thickness, dose also increases. But as increasing the x-ray tube voltage, dose decreases because of high penetrating ratio through the object. But high tube voltage is reducing the subject contrast. From this result, we have to consider the trade-off between subject contrast of image and dose to the patient and choose proper x-ray energy range.

• Journal of the Korean Geographical Society
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• v.32 no.4
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• pp.543-548
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• 1997

New technologie of information and interaction create ambiguous, multifaceted relationships between concepts and realities that once seemed clear and simple. The acvent of cyberspace implies the existence of cyberplaces and relationships among cyberspace and places that could be as or more complex then those that exist among the spaces and places of the non-digital world. Virtual reality-the current uses of infomation technologies to create replicas of places and processes in the world-offers a point of exploring such relationships. But more penetrating insights become evident in the examination of real virtuality-the uses of information technologies to enhance the experience of places in the world. Real virtuality offers geographers a variety of innovative and powerful tools for augmenting the effectiveness and domain of their craft. Widespread use of real virtuality by geograpgers will alter their use of data, methods, and theory in research, teaching, and practice.

• Journal of the Korean earth science society
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• v.29 no.5
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• pp.428-436
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• 2008

This study observed the upper tropospheric ozone enhancement in the northern Atlantic for the Aerosols99 campaign in January-February 1999. To find the origin of this air, we have analyzed the horizontal and vertical fields of Isentropic Potential Vorticity (IPV) and Relative Humidity (RH). The arch-shaped IPV is greater than 1.5 pvus indicating stratospheric air stretches equatorward. These arch-shaped regions are connected with regions of RH less than 20%. The vertical fields of IPV and RH show the folding layer penetrating into the upper troposphere. These features support the idea that the upper tropospheric ozone enhancement originated from the stratosphere. Additionally, we have investigated the climatological frequency of stratospheric intrusion over the tropical north Atlantic using IPV and RH. The total frequency between the equator and $30^{\circ}N$ over the tropical north Atlantic exhibits a maximum in northern winter. It suggests that the stratospheric intrusion plays an important role in enhancing ozone in the upper troposphere over the tropical north Atlantic in winter and early spring. Although the tropospheric ozone residual method assumed zonally invariant stratospheric ozone, stratospheric zonal ozone variance could be caused by stratospheric intrusions. This implies that stratospheric intrusion influences ozone variance over the Atlantic in boreal winter and spring, and the intrusion is a possible source for the tropical north Atlantic paradox.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.1
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• pp.49-56
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• 1997

Heat-transfer enhancement is seeked through modifications of fin surface. Real life plate-fin heat exchangers have complex three-dimensional geometries. Fins can have arrays of dimples and are attached to rows of penetrating tubes. To isolate the effect of surface modification, we model the real flow by a two-dimensional channel flow with a dimple on one side. The flow is analysed by solving the incompressible Navier-Stokes equation by a finite volume method on a generalized boundary-fitted coordinate. Results show a trapped vortex inside the dimple for all cases computed. Local maximum of Nusselt number occurs near the downstream end of the dimple, due to such a vortex. Location of the vortex does not change with respect to the wall temperature change, but moved downstream when Reynolds number increases. This, together with the results that in all cases vortex core is somewhat downstream of the dimple center, suggests that the mean flow above continuously feeds the kinetic energy to the recirculating flow. Heat transfer enhancement and pressure losses are studied through analysing the relevant dimensionless parameters like, Nusselt number and friction factor. In all cases computed, dimpled channel flow experiences less pressure loss than two-dimensional Poiseuille flow.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.312-315
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• 2005

Bleeding due to cardiac perforation by endocardial pacemaker lead is a rare complication. We report one case of left hemothorax due to right ventricular perforation after the insertion of permanent transvenous pacemaker. Operative finding showed a pacing lead penetrating right ventricle, pericardium, and left pleura sequentially, but there was no evidence of hemopericardium.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.252-256
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• 2002

Since early 1990s, construction companies in Korea have tired to adopt knowledge management(KM) which has been emphasized by enterprises in advanced countries and academic researches to sustain competitive advantages. However, concentrations were onto applying KM without measuring current status level of knowledge management in their organizations. Therefore, competitive advantages can hardly meet their prior expectations, still less penetrating into the organizations. As a result, this research presents strategic model measuring organizational status of knowledge management originated by interviews and questionnaires on companies.

• The Korean Journal of Pain
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• v.13 no.2
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• pp.237-241
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• 2000

Vertebral compression fractures commonly afflict the elderly. Some patients suffer from severe mechanical pain in spite of treatments with strong analgesics and bracing. Vertebroplasty, which was originally used for vertebral hemangioma, is effective for patients who do not respond to these more conservative treatments. However, the procedure has some risk. Leaks of bone cement into perineural tissues can be a serious complication. In contrast to the lumbar vertebrae, the outer margin of the pedicle of the thoracic vertebrae is almost in line with the outer margin of the body. This, combined with the thinner pedicle of the thoracic vertebrae, makes proper needle placement difficult. The posterolateral approach is preferred to the transpedicular approach in order to avoid the danger of destroying the inner cortex of the pedicle. But there can be a problems with the standard posterolateral approach. The rib can be broken, the pleura can be punctured. A new and safer approach is possible. Before penetrating the bone, the needle is positioned at the upper margin of the transverse process, 5 mm away from the pedicle. To achieve this positioning, the needle must puncture the skin 1~1.5 cm laterally and 3~5 mm cranially to the target point on the bone. This approach was used for 10 patients and we achieved good results with no serious complication.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.4
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• pp.288-297
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• 2009

A serpentine channel geometry often used in a fuel cell has a strong pressure gradient between adjacent channels in specific regions. The pressure gradient helps some amount of reactant gas penetrate through a gas diffusion layer(GDL). As a result, the overall serpentine flow structure is slightly different from the intention of a designer. The purpose of this paper is to examine the effect of serpentine flow structure on current density distribution. By using a commercial code, STAR-CD, a numerical simulation is performed to analyze the fuel cell with high aspect ratio of active area. To increase the accuracy of the numerical simulation, GDL permeabilities are measured with various compressive forces. Three-dimensional flow field and current density distribution are calculated. For the verification of the numerical simulation results, water condensation process in the cathode channel is observed through a transparent bipolar plate. The result of this study shows that the region of relatively low current density corresponds that of dropwise condensation in cathode channels.

• Journal of Trauma and Injury
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• v.24 no.1
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• pp.7-11
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• 2011

Purpose: Traumatic airway injuries have high rates of mortality and morbidity. Thus, we evaluated the clinical results of trauma-related airway-injury patients. Methods: A clinical analysis was performed for patients with airway trauma who were admitted and treated at the Department of Thoracic and Cardiovascular Surgery, Konyang University Hospital from Dec. 2002 to Dec. 2009. Results: Sixteen patients were admitted and treated. Fourteen patients were male, and the ages of the patients ranged from 16 to 75 years. Six cases were penetrating injuries, 4 were traffic-accident injuries. 3 were fall injuries, and. 3 were other blunt trauma injuries. Anato- mic injuries included 14 trachea cases (87.5%), 1 Rt. main bronchus (6.25%), and 1 Lt. main bronchus cases (6.25%). Diagnosis was made by using computed tomography and bronchoscopy. Five patients were treated with an explothoracotomy, and 7 underwent neck exploration with primary repair. Three patients simply needed conservative management, and 1 patient was treated with a closed thoracostomy. The post-operative mortality rate was 6.25 % (1 patient). Conclusion: Airway trauma is dangerous and should be treated as an emergency, so a high index of suspicion is essential for rapid diagnosis and successful surgical intervention in patients with airway injuries.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.148-155
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• 2010

After the first-ever international espresso coffee shop Starbucks Korea opened its first branch near Ewha University in Korea, positioning of divers foreign cultures among us and changes of life style due to the gross income growth have leaded to the growth of the number of needs for espresso coffee shops and, therefore, international espresso shops have been launching their shops in Korea. While the foreign shops have been holding most of the domestic market share, domestic espresso coffee shops like Hollys and Angel-In-Us have been penetrating the market with differentiated marketing strategies that a espresso coffee shop is no longer considered as just a shop, but a cultural product to Korean. Along with the recent changes, customers have started to laying emphasis on interior and each of the domestic coffee shops has been changing its interior designs by establishing own brand identification. Base on the Starbucks' success case, the domestic coffee shops have been adopting emotional marketing which would stimulate and arouse customers' emotions. The purpose of this study is to present systematic data which would be applied in an espresso coffee shop planning by researching applied emotional design elements of the domestic coffee shops interior designs in depth and finding their characteristics.