• Archives of Plastic Surgery
• /
• v.36 no.5
• /
• pp.629-636
• /
• 2009

Purposes: Wide scars occurring on the lower face and neck are a source of both functional and esthetic problems. Consequently, we can use skin grafts, pedicled flaps, free flaps, and tissue expansion for the reconstruction of this area. Compared with other reconstruction techniques, tissue expansion is advantageous in that it enables the maintenance of a color and texture similar to that of the adjacent tissue. However, the conventional method of tissue expansion has been reported to lead to an unnatural cervicomental angle and to the deformity of adjacent structures. We have therefore made efforts to prevent these problems through the use of several operative procedures. Methods: Forty-one patients with lower facial and cervical scars underwent tissue expansion. The tissue expansion was performed using a rectangular-shaped Nagosil$^{(R)}$ tissue expansion device. On insertion of the tissue expander, the intermediate area of superficial fat layer was dissected and then the tissue expander was inserted to make a flap that was as thin as possible. In advancement of the flap, a capsule-formed by the tissue expander-was used for the interrupted fixed suture of the flap to the fascia of the platysma muscle of the neck. This procedure was performed multiple times and also performed between the flap and the periosteum of the mandible, such that the tension was removed during the suture of the flap margin. Finally, the patients were fitted with a Jobst$^{(R)}$ facial garment in order to stabilize the operation site at least twelve months. Results: The most prevalent location of the scar was the cheek (15 cases), followed by the chin in 14 cases and the neck in 12 cases. The mean size of scar was $55.7{\pm}39.4cm^2$. Conclusions: Using our procedures, we have experienced no significant deformities and have also achieved a more natural cervicomental angle in the patients.

• Journal of Korean Ophthalmic Optics Society
• /
• v.13 no.4
• /
• pp.31-36
• /
• 2008

Purpose: To investigate optical shop startup awareness of ophthalmic optics students as a basic source for startup education. Methods: Total of 287 students from three ophthalmic optics college in kyung-gi region was surveyed and analyzed using SPSS analysis. Results: Optical shop startup business plan of ophthalmic optics students was very high (80.1%). For startup timing, over 6yrs of employe (37.0%) was most and there was significant difference according to age (p<.001) and optician family present (p<.05). For startup type, single startup type (37%) was most and there was significant difference according to grade (p<.01). For startup unit of space, 30 pyong (43.5%) was most, Seoul metropolitan area and kyung-gi region (54.4%) was most for startup region, and station area (40.8%) was most for startup location. The reason of non-startup was eye hospital and glass related company employe (35.7%) was most and optical shop employe (35.7%) was most for non-startup planner's way. Conclusions: Startup business plan was very high and need to have startup education for there startup provision.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.2
• /
• pp.189-196
• /
• 2005

Recently as map making skills developed and as digital maps prevailed, peoples began to take interest in the realistic 3dimension topography rather than the flat 2 dimension one. The experiment is done by using the topographical information from the digital maps, To analyze the preciseness of this 3dimension topography, analysis of the coordinate-changed standard map image and the location errors of the plane and height from digital values of the map's topography by layers and features, were done. The visual results of locational values differed by every programs of coordinate transformation. Errors of locations also appeared from the methods of correcting the visual sources, when deciding the standard source's datum point. The plan's accuracy of the image data coordinate transformation is about ${\pm}4.1m$. In ground distance, therefore, it is included in the allowed error of the 1:25,000 scale changed map, satisfying the plan's accuracy. Also, by the use of reasonably spaced grid, it satisfied the visual topographical accuracy. Because the 3 dimension topographical map can be produced effectively and rapidly by using various scale's standard map image and the digital map, the further practical use of 3 dimension topographic map made by using the existing topographies and changed maps has high expectations.

• Cross-Cultural Studies
• /
• v.34
• /
• pp.93-114
• /
• 2014

Gaston Bachelard had a revolutionary progress in the field of human understanding by proposing his theory of image and imagination. His theory of the new image was so powerful, almost all areas of human science, particularly that of literary criticism, were strongly influenced and this influence continues until today. Today almost everyone accepts his theory of the image without much objection, but not rarely asked where began his transfer from the philosophy of science to the images. We propose a hypothesis that the beginning of the new concept of Bachelard's image was inspired by studies of contemporary science, especially quantum mechanics. The Heisenberg's uncertainty principle was the core of quantum mechanics, and opens new perspectives on the material world. We could summarize the message of the uncertainty principle : the material world is made up of various layers, and the material can not be measured by the location and movement at the same time. So we must have a new point of view of another dimension to know this material world. Bachelard had accepted this view of Heisenberg and developed his own theory of epistemological rupture. What is revolutionary in the theory of Bachelard's image is the fact that he looked at the images with the new perspective. The human psyche is another world compared to the rational world that dominates our daily lives. Bachelard insists that the image can not be explained by the concept. The fantasy world is a totally different world to that of rationality. That is why it can not be explained by the language of rationality as the concept. The imaginary world exists independently of the real world, but it is superimposed on the real world. These two worlds are influencing each other, and it is between these two world where our daily lives continues. The declaration of Bachelard 'image is a specific reality' is never a metaphor or rhetorical expression. This is an ontological expression that must truthfully. The imaginary world is a world built on the image and it works according to its own law. It is not a representation or copy of the real world. But the world of imagination are not alone. It exists in the same time and space with the world of science. It is superimposed with the world of science. Both two world influence each other. Bachelard has made a revolutionary change by studying the images. He gave them their own place. It has changed the views on the images that were treated as mere representations of reality. Thanks to him, the image can have its own value, that of a factor that creates reality. Bachelard shows how we can go deep into the source of being and the universe if we look at the pictures with the eyes of other dimensions.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.5
• /
• pp.683-690
• /
• 2021

The ventilation system of the engine room of a ship is generally installed to supply the combustion air necessary for the internal combustion engine and to remove the heat source generated in the engine room, and it must satisfy the international standard (ISO 8861) for the design conditions and calculation standards for the ventilation of the ship engine room. The response delay of the ventilation system including the fire detector is affected by the airflow formed inside the area and the location of the fire detector. In this study, to improve the initial fire detection response speed of a fire detector installed on a fishing vessel and to maintain the sensitivity of the installed detector, the smoke behavior was simulated using the air flow field inside the engine room, the amount of combustion air in the internal combustion engine, and the internal pressure of the engine room as variables. Analysis of the simulation results showed that reducing the flow rate in the air flow field and increasing the vortex by reducing the internal pressure of the engine room and installing a smoke curtain would accelerate the rise of the ceiling of the smoke component and improve the smoke detector response speed and ventilation system.

• KIPS Transactions on Computer and Communication Systems
• /
• v.7 no.12
• /
• pp.301-312
• /
• 2018

In industrial wireless sensor networks, the continuous object detection such as fire or toxic gas detection is one of major applications. A continuous object occurs at a specific point and then diffuses over a wide area. Therefore, many studies have focused on accurately detecting a continuous object and delivering data to a static sink with an energy-efficient way. Recently, some applications such as fire suppression require mobile sinks to provide real-time response. However, the sink mobility support in continuous object detection brings challenging issues. The existing approaches supporting sink mobility are designed for individual object detection, so they establish one-to-one communication between a source and a mobile sink for location update. But these approaches are not appropriate for a continuous object detection since a mobile sink should establish one-to-many communication with all sources. The one-to-many communication increases energy consumption and thus shortens the network lifetime. In this paper, we propose the origin-centric communication scheme to support sink mobility in a continuous object detection. Simulation results verify that the proposed scheme surpasses all the other work in terms of energy consumption.

• Journal of radiological science and technology
• /
• v.42 no.3
• /
• pp.167-173
• /
• 2019

The Cobey method and the modified Cobey method are most commonly used in clinical practice. Therefore, the purpose of this study was to investigate the radiological differences between Cobey and modified Cobey and provide radiographic information about changes of hindfoot image with X-ray entrance center and tube angle change in modified Cobey. This study was performed on foot and ankle phantom. First, for image comparison of Cobey and modified Cobey, the images obtained by applying the same X-ray entrance center to the ankle joint were compared and analyzed. Second, in the modified Cobey, the X-ray entrance center is set as ankle joint and lateral malleolus. The X-ray tube angle was varied from $10^{\circ}$ to $40^{\circ}$ at $5^{\circ}$ intervals for each X-ray entrance center. The images obtained by varying the X-ray tube angle from $10^{\circ}$ to $40^{\circ}$ at intervals of $5^{\circ}$ for each X-ray entrance center were compared and analyzed. The irradiation conditions were the same with 110 kVp, 200 mA, 10 ms, and 110 cm of source - image receptor distance (SID). Image evaluation was performed by two radiologists. Measurements were made on the lateral point, middle point, and calcaneus width based on a hypothetical line parallel to the calcaneal tuberosity. Data were analyzed by using descriptive statistics as the mean of the distance to each measurement location. The modified Cobey was longer than the Cobey by an average of 3 to 4 mm lateral and medial points, and the calcaneus width was similar (ICC = 0.939). In modified Cobey method, when the X-ray entrance center is ankle joint, the lateral point is about 3 mm and the medial point is about 4.3 mm longer than lateral malleolus. Also, when the X-ray tube angle is more than $20^{\circ}$, the degree of distortion is large. The ICCs for the lateral, medial point, and calcaneus width were 0.998, 0.961, and 0.997, respectively, as the X-ray entrance center and tube angle were changed. There was no significant difference between Modified Cobey and Cobey. Modified Cobey showed no need to compensate the $20^{\circ}$ detector angle of the Cobey. In addition, we suggest that tube angle should be limited within $20^{\circ}$ when modified Cobey is performed.

• Journal of Positioning, Navigation, and Timing
• /
• v.7 no.4
• /
• pp.295-305
• /
• 2018

Network RTK is a highly practical technology that can provide high positioning accuracy at levels between cm~dm regardless of user location in the network by extending the available range of RTK using reference station network. In particular, unlike other carrier-based positioning techniques such as PPP, users are able to acquire high-accuracy positions within a short initialization time of a few or tens of seconds, which increases its value as a future navigation system. However, corrections must be continuously received to maintain a high level of positioning accuracy, and when a time delay of more than 30 seconds occurs, the accuracy may be reduced to the code-based positioning level of meters. In case of SSR, which is currently in the process of standardization for PPP service, the corrections by each error source are transmitted in different transmission intervals, and the rate of change of each correction is transmitted together to compensate the time delay. Using these features of SSR correction is expected to reduce the performance degradation even if users do not receive the network RTK corrections for more than 30 seconds. In this paper, the simulation data were generated from 5 domestic reference stations in Gunwi, Yeongdoek, Daegu, Gimcheon, and Yecheon, and the network RTK and SSR corrections were generated for the corresponding data and applied to the simulation data from Cheongsong reference station, assumed as the user. As a result of the experiment assuming 30 seconds of missing data, the positioning performance compensating for time delay by SSR was analyzed to be horizontal RMS (about 5 cm) and vertical RMS (about 8 cm), and the 95% error was 8.7 cm horizontal and 1cm vertical. This is a significant amount when compared to the horizontal and vertical RMS of 0.3 cm and 0.6 cm, respectively, for Network RTK without time delay for the same data, but is considerably smaller compared to the 0.5 ~ 1 m accuracy level of DGPS or SBAS. Therefore, maintaining Network RTK mode using SSR rather than switching to code-based DGPS or SBAS mode due to failure to receive the network RTK corrections for 30 seconds is considered to be favorable in terms of maintaining position accuracy and recovering performance by quickly resolving the integer ambiguity when the communication channel is recovered.

• Journal of the Korean Society of Radiology
• /
• v.13 no.4
• /
• pp.661-666
• /
• 2019

Diverging collimators is used to obtain reduced images of an object, or to detect a wide filed-of-view (FOV) using a small gamma camera. In the gamma camera using the diverging collimators, the block scintillator, and the pixel scintillator array, gamma rays are obliquely incident on the scintillator surface when the source is located the periphery of the FOV. Therefore, the spatial resolution is reduced because it is obliquely detected in depth direction. In this study, we designed a novel system to improve the spatial resolution in the periphery of the FOV. Using a tapered crystal array to configure the scintillation pixels to coincide with the angle of the collimator's hole allows imaging to one scintillation pixel location, even if events occur to different depths. That is, even if is detected at various points in the diagonal direction, the gamma rays interact with one crystal pixel, so resolution does not degrade. The resolution of the block scintillator and the tapered crystal array was compared and evaluated through Geant4 Application for Tomographic Emission (GATE) simulation. The spatial resolution of the obtained image was 4.05 mm in the block scintillator and 2.97 mm in the tapered crystal array. There was a 26.67% spatial resolution improvement in the tapered crystal array compared to the block scintillation.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.31 no.2
• /
• pp.62-72
• /
• 2019

Due to the difficulties in forecasting the intensity and the source location of tsunami the countermeasures prepared based on the deterministic approach fail to work properly. Thus, there is an increasing demand of the tsunami hazard analyses that consider the uncertainties of tsunami behavior in probabilistic approach. In this paper a fundamental study is conducted to perform the probabilistic tsunami hazard analysis (PTHA) for the tsunamis that caused the disaster to the east coast of Korea. A logic tree approach is employed to consider the uncertainties of the initial free surface displacement and the tsunami height distribution along the coast. The branches of the logic tree are constructed by reflecting characteristics of tsunamis that have attacked the east coast of Korea. The computational time is nonlinearly increasing if the number of branches increases in the process of extracting the fractile curves. Thus, an improved method valid even for the case of a huge number of branches is proposed to save the computational time. The performance of the discrete weight distribution method proposed first in this study is compared with those of the conventional sorting method and the Monte Carlo method. The present method is comparable to the conventional methods in its accuracy, and is efficient in the sense of computational time when compared with the conventional sorting method. The Monte Carlo method, however, is more efficient than the other two methods if the number of branches and the number of fault segments increase significantly.