• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.143-149
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• 2005

Objects : With the advancement of tissue engineering techniques, the effort to develop bioartificial mucosa have been actively delivered. The problem we met with this technique is the lack of mechanical strength between kerationocyte layer and dermal layer, where in the normal skin and mucosa, they are tightly bound with rete ridge structure. The purpose of this study is to understand the 2D and 3D structure of rete ridge of mucosa and skin paddle for rendering more biomimetic structure to the artificial mucosa. Materials and Methods : Oral mucosa and skin from the patients who received the oral surgery and maxillofacial reconstruction were harvested. The epidermis was separated from the dermis after treating with dispase for 12-16 hours. H&E staining was performed for 2D(dimensional) structure study and confocal LASER and SEM study were performed for 3D structure. Mean height(Sc) and arithmetic mean deviation(Sa) of all surface height were calculated. Results : The average height of rete ridge of skin flap was between $67.14{\mu}m$ and $194.55{\mu}m$. That of oral mucosa was between $146.26{\mu}m$ and $167.51{\mu}m$. Pressure bearing area and attached gingiva of oral mucosa showed deeper rete ridges. Conclusion : To obtain the adequate strength of artificially cultured keratinocyte skin and mucosa flap, it is necessary to imitate the original skin and mucosa structure, especially rete ridge. Through this study, 2D and 3D rete ridge structure of normal mucosa and skin was obtained. These results can be used as basis for substrate morphology for keratinocytes culture.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.628-645
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• 2010

To perform the engagement level simulation between the underwater vehicle model and the surface model those are constituted with various systems/ sub-systems, we implemented four different federates as a federation according to the IEEE 1516 HLA (High Level Architecture) protocol that is the international standard in the distributed simulation. Those are CFCS (Command and Fire Control System) federate, motion federate, external entities (torpedos, countermeasure and surfaceship) federate, and visualization federate that interacts with OSG (Open Scene Graph)-based visualization rendering module. In this paper, we present the detailed method about the model constitution for discrete event simulation in the distributed environment. For the sake of this purpose, we introduce the DEVS (Discrete Event System Specification)-HLA-based modeling method of the CFCS federate that reflects not only the interations between models, but also commands from user and tactics manager that is separated from the model. The CFCS federate makes decisions in various missions such as the normal diving, the barrier misision, the target motion analysis, the torpedo launch, and the torpedo evasion. In the perspective of DEVS modeling, the CFCS federate is the coupled model that has the tactical data process model, command model and fire control model as an atomic model. The message passing and time synchronization with other three federates are settled by the $m\ddot{a}k$ RTI (Runtime Infrastructure) that supports IEEE 1516. In this paper, we provides the detailed modeling method of the complicated model that has hierarchical relationship such as the CFCS system in the submarine and that satisfies both of DEVS modeling method for the discrete event simulation and HLA modeling method for the distributed simulation.

• Journal of Gastric Cancer
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• v.3 no.4
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• pp.195-200
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• 2003

Purpose: Advancement of computed tomography (CT) hardware and software has allowed thin section scanning and reconstruction of fascinating 2-dimentional (2D) and 3- dimentional (3D) images. Especially, the reconstruction of 3D images of gastrointestinal tract has been used in the detection and diagnosis of pre-malignant and malignant diseases. To compare the efficacy of CT gastrography with conventional upper gastrointenstinal series (UGIs) in gastric cancer patients. Materials and Methods: During Nov. 2002 and Mar. 2003, twenty-seven patients who had gastric cancer received both double contrast upper GI series and CT gastrography prior to radical surgery. Among these patients, nineteen had early gastric cancer (EGC) and 8 had advanced gastric cancer (AGC). Fifteen patients were male and 12 were female. The mean age was 54 yrs (range, $27\∼75$ yrs). The patients were placed on NPO and Stomach was distended with gas in fasting state prior to CT scanning. Double contrast upper GI series were performed as routine manual. CT scan was conducted in all patients using 8 or 16-channel multidetector CT in this study. The collimation and reconstruction for CT scanning were set at 2.5 mm and 1.25 mm, respectively. CT scanning was performed in the supine position. For image processing, CT gastrography, in which raysum and surface rendering images were constructed, virtual and 2D image in coronal and sagittal images were performed. The detectability of gastric cancer was assessed between UGIs and CT gastrography. Results: In AGCs, the detection rate of cancer using CT gastrography and virtual gastroscopy was higher than EGC cases. However, CT gastrography and virtual gastroscopy showed less favorable results than UGIs. Even though only a small number of cases had been studied, we might conclude that CT gastrography and virtual gastroscopy could replace UGIs in the detection of AGC cases. Conclusion: The detection rate used with CT gastrography and Virtual gastroscopy is not better than that of UGIs in early gastric cancer, however, in advanced gastric cancer cases, it is nearly equal to that of UGIs.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.737-743
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• 2014

This paper dealt with a retrofit high power LED searchlight to replace conventional 1kW halogen searchlights. The design specification meets KDS 6230-1046-1 and KS V 8469. An optical lens with the beam angle of $6^{\circ}$ was used to meet the luminous intensity of 800,000cd at $0^{\circ}$ in horizontal line. Heat dissipation of the LED searchlight adopted a free air cooling type which does not use a fan or a heat-pipe. From the test results, power consumption of the prototype LED searchlight was 148W which was saved by 85% comparing a halogen searchlight of 1kW. Luminous intensity was 945,000cd at $0^{\circ}$ in horizontal line, satisfying KS V 8469. Luminous efficacy was improved by 4.7 times higher than that of the halogen searchlights. Beam angle, color temperature, and color rendering index(CRI) was $5.4^{\circ}$, 5,500K, and 70, respectively. Surface temperature of the LED searchlight was below $60^{\circ}C$ and surrounding temperature of the SMPS installed inside was below $50^{\circ}C$ which were satisfied with the IEC 60092-306.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.192-197
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• 2002

Fluorescent in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes was used to compare the community structures of free-living and aggregated bacteria at thawing period in Lake Baikal. Targeted groups were Eubacteria, $\alpha$-, $\beta$-, $\gamma$- proteobacteria groups, Cytophaga-Flavobacterium group and Planctomycetales. Total bacterial numbers of free-living bacteria were ranged from $0.2{\times}10^6\cells{\cdot}ml^-1$ to $3.2{\times}10^6\cells{\cdot}ml^-1$, which were decreasing with depth, while the aggregated bacterial numbers were dramatically increasing from $0.4{\times}10^4 to 3.3{\times}10^4 \cells{\cdot}ml^-1$ with depth. The ratios of EUB probe binding cells to DAPI counts were ranged from 52.3 to 74.1% in free-living bacteria, and from 39.6 to 66.7% in the aggregated bacteria, respectively. Community structures of the aggregated bacteria were very different from each free-living bacteria at every depth. At 25 m depth, where the chlorophyll a concentration was highest, both structures were quite different from those of surface layers, rendering the fact that the community structures might be affected by phytoplankton. The vertical profile of community structure of aggregated bacteria is particular. The proportion of $\beta$-proteobacteria group was increasing with depth and it was 51.8% at 100 m, but the dominant group was $\gamma$-pro-teobacteria group at 250 m. Taken together, the biodiversity and succession of aggregated bacteria are quite different from free-living bacteria.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.67-75
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• 2024

In the context of Korean residential heating systems, Ondol pipelines are a prevalent choice. However, the maintenance of these pipelines becomes a complex task once they are embedded within concrete structures. As time progresses, the accumulation of sludge, corrosive oxides, and microorganisms on the inner surfaces of these pipelines diminishes their heating efficiency. In extreme scenarios, this accumulation can induce corrosion and scale formation, compromising the system's integrity. Consequently, this research introduces an ultrasonic generation system tailored for the upkeep of Ondol pipelines, with the objective of empirically assessing its practicality. This investigation delineates three variants of ultrasonic generating apparatuses: those employing surface vibration, external generation, and internal generation techniques. To emulate the presence of contaminants within the pipelines, substances in powder, slurry, and liquid forms were employed. The efficacy of the cleaning process post-ultrasonic wave application was scrutinized over time, with image analysis methodologies being utilized to evaluate the outcomes. The findings indicate that ultrasonic waves, whether generated externally or internally, exert a beneficial effect on the cleanliness of the pipelines. Given the inherent characteristics of Ondol pipelines, external generation proves impractical, thereby rendering internal generation a more viable solution for pipeline maintenance. It is anticipated that future endeavors will pave the way for innovative maintenance strategies for Ondol pipelines, particularly through the advancement of internal generation technologies for pipeline applications.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.161-166
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• 2006

Purpose: Recently, the incidence of early gastric cancer (EGC) patients is rapidly increased in Korea. However, they're often not perceptible by surgical palpation or inspection. The aim of this study is 1) to develope a software that can locate the tumor and measure the mucosal distance from an anatomic landmark to the tumor using CT gastrography and 2) to compare the distance measured by the developed software with the distance measured by the pathologic findings. Materials and Methods: Between January 2004 and September 2005, sixty patients (male=45, female=15, mean 57.8 years old) estimated for EGC with preoperative CT scans and undergone gastrectomies in Kyungpook National University Hospital were enrolled in this study. Preoperative CT scans were performed after insufflations of room air via 5 Fr NG tube. The scans included the following parameters: (slice thickness/reconstruction interval: 0.625 mm, kVp: 120, mAs: 200). 3D volume rendering and measurement of the surface distance from the pylorus to the EGC were performed using the developed software. Results: The average difference between the lesion to pylorus distances measured from pathologic specimens and CT gastrography was $5.3{\pm}2.9\;mm(range,\;0{\sim}23\;mm)$. The lesion to pylorus distance measured from CT gastrography was well correlated with that measured from the pathologic specimens (r=0.9843, P<0.001). Conclusion: These results suggest that the surface distance from an anatomic landmark to the EGC can be measured accurately by CT gastrography. This technique could be used for preoperative localization of early gastric carcinomas to determine the optimal extent of surgical resection.

• Anatomy & Biological Anthropology
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• v.31 no.4
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• pp.133-142
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• 2018

3D histology is a imaging system for the 3D structural information of cells or tissues. The synchrotron radiation propagation phase contrast micro-CT has been used in 3D imaging methods. However, the simple phase contrast micro-CT did not give sufficient micro-structural information when the specimen contains soft elements, as is the case with many biomedical tissue samples. The purpose of this study is to develop a new technique to enhance the phase contrast effect for soft tissue imaging. Experiments were performed at the imaging beam lines of Pohang Accelerator Laboratory (PAL). The biomedical tissue samples under frozen state was mounted on a computer-controlled precision stage and rotated in $0.18^{\circ}$ increments through $180^{\circ}$. An X-ray shadow of a specimen was converted into a visual image on the surface of a CdWO4 scintillator that was magnified using a microscopic objective lens(X5 or X20) before being captured with a digital CCD camera. 3-dimensional volume images of the specimen were obtained by applying a filtered back-projection algorithm to the projection images using a software package OCTOPUS. Surface reconstruction and volume segmentation and rendering were performed were performed using Amira software. In this study, We found that synchrotron phase contrast imaging of frozen tissue samples has higher contrast power for soft tissue than that of non-frozen samples. In conclusion, synchrotron radiation propagation phase contrast cryo-microCT imaging offers a promising tool for non-destructive high resolution 3D histology.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.115-121
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• 2008

Purpose: Aortic Dissection is very dangerous, prognostic disease, which the bloodstream flow out of the true lumen of the aorta by the bursting of aortic intima resulting in a rapid dissociation of inner and outer layer from the media. It is difficult to diagnose aortic dissection clinically by normal X-ray. This study was to investigate the occurrence frequency by age and number of patients who are identified to be aortic dissection by CT (Computed Tomography) scan. Materials and methods: We investigated the trend of yearly fluctuation, gender, age, and department of clinical research of the 112 patients who conducted CT scan in C- University Hospital for two years from January 2005 to December 2006. The MIP and SSD which reconstructed CT image and the VRT image were obtained for the accurate observation. The result was investigated by comparing normal X-ray and CT scan. Results and Conclusion: 1. The yearly check of 112 patients conducted CT scan showed 37 people (41.9%) in 2005, and it was increased to 65 (58.1%) in 2006 by 1.4 times. 2. The gender distribution of patients given a CT scan showed 45 males (40.1%), and female 67 (59.9 %). The aortic dissection patients were 9 (20%) out of 45 males, 21 (31.3%) out of 67 females and women were 1.6 times more than men. Women are also 1.5 times more than men in the number of examinee. 3. The age distribution of patient's who conducted CT scan revealed that there was no patient under 30 years old while 88.3% of all patients were through 41 to 80 years old. The higher the age was, the higher the occurrence of aortic dissection was. The difference in the occurrence frequency of age was statistically significant (p<0.01). 4. The departments that requested CT scan were the emergency department 46 (41.1%), circulatory internal medicine 37 (33.0%), chest surgery 13 (11.6%), and others 6 (14.3%). The combined ratio of emergency medicine and circulatory internal medicine was 74.1% of all. The results show that the aortic dissection is a very dangerous disease whose patients visit mainly via the emergency room. 5. The aortic dissection patients had normal X-ray readings in 22 (73.3%) out of 30, and only 8 (26.7 percent) are abnormal in the X-ray diagnosis. Therefore, the CT scan needs to be enforced in order to assess accurately the disease of aortic dissection.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.101-112
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• 2018

This study was carried out to enhance the competitiveness of blackbox design for domestic and international companies, based on the explosive growth of the blackbox market due to development of blackbox design for vehicle accident prevention and post-treatment. In the past, the blackbox market has produced products indiscriminately to meet the ever-increasing demand of consumers. Therefore, we thought a new design method was necessary to effectively investigate the needs of rapidly changing consumers. In this study, we aimed to identify the best-selling blackbox to understand the design flow, and the optimum area for a blackbox, considering the uniqueness of associated vehicle. Based on discussion with blackbox design experts, we studied the direction of design and the problems with blackbox use, which were reflected in blackbox development. Through this research, two types of design - leading blackbox (A type) and mass production blackbox (B type) - were proposed for compatibility of the blackbox with the car. The leading type of blackbox was positioned so that it was wrapped with the room mirror hinge before the screw was fastened, in order to achieve an integrated design. Therefore, we designed an integrated form and resolved the placement problem of an adhesive blackbox. To blend, the mass production blackbox implemented material and surface processing in the same way with the car, and adopted the slide structure to automatically turn off the main body power when removing the SDcard, reflecting consumer needs. This study considers evolving consumer needs through a case study and collective intelligence and deals with implementation of the whole design process during mass production. In this study, we aimed to strengthen the competitiveness of the blackbox design based on design method and its realization.