• The Korean Journal of Archival Studies
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• no.74
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• pp.45-78
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• 2022

South Africa implemented apartheid from 1948 to 1994. The main content of this policy was to classify races such as whites, Indians, mixed-race people, and blacks, and to limit all social activities, including residence, personal property ownership, and economic activities, depending on the class. All races except white people were discriminated against and suppressed for having different skin colors. South African citizens resisted the government's indiscriminate violence, and public opinion criticizing them expanded beyond the local community to various parts of the world. One of the things that made this possible was photographs detailing the scene of the violence. Foreign journalists who captured popular oppression as well as photographers from South Africa were immersed in recording the lives of those who were marginalized and suffered on an individual level. If they had not been willing to inform the reality and did not actually record it as a photo, many people would not have known the horrors of the situation caused by racial discrimination. Therefore, this paper focuses on Rise and Fall of Apartheid: Photography and the Bureau of Everyday Life, which captures various aspects of apartheid and displays related records, and examines the aspects of racism committed in South Africa described in the photo. The exhibition covers the period from 1948 when apartheid began until 1995, when Nelson Mandela was elected president and the Truth and Reconciliation Commission was launched to correct the wrong view of history. Many of the photos on display were taken by Peter Magubane, Ian Berry, David Goldblatt, and Santu Mofoken, a collection of museums, art galleries and media, including various archives. The photographs on display are primarily the work of photographers. It is both a photographic work and a media that proves South Africa's past since the 1960s, but it has been mainly dealt with in the field of photography and art history rather than from a historical or archival point of view. However, the photos have characteristics as records, and the contextual information contained in them is characterized by being able to look back on history from various perspectives. Therefore, it is very important to expand in the previously studied area to examine the time from various perspectives and interpret it anew. The photographs presented in the exhibition prove and describe events and people that are not included in South Africa's official records. This is significant in that it incorporates socially marginalized people and events into historical gaps through ordinary people's memories and personal records, and is reproduced in various media to strengthen and spread the context of record production.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.25-32
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• 2021

In line with future changes in the marine environment, Aids to Navigation has been used in various fields and their use is increasing. The term "Aids to Navigation" means an aid to navigation prescribed by Ordinance of the Ministry of Oceans and Fisheries which shows navigating ships the position and direction of the ships, position of obstacles, etc. through lights, shapes, colors, sound, radio waves, etc. Also now the use of Aids to Navigation is transforming into a means of identifying and recording the marine weather environment by mounting various sensors and cameras. However, Aids to Navigation are mainly lost due to collisions with ships, and in particular, safety accidents occur because of poor observation visibility due to sea fog. The inflow of sea fog poses risks to ports and sea transportation, and it is not easy to predict sea fog because of the large difference in the possibility of occurrence depending on time and region. In addition, it is difficult to manage individually due to the features of Aids to Navigation distributed throughout the sea. To solve this problem, this paper aims to identify the marine weather environment by estimating sea fog level approximately with images taken by cameras mounted on Aids to Navigation and to resolve safety accidents caused by weather. Instead of optical and temperature sensors that are difficult to install and expensive to measure sea fog level, sea fog level is measured through the use of general images of cameras mounted on Aids to Navigation. Furthermore, as a prior study for real-time sea fog level estimation in various seas, the sea fog level criteria are presented using the Haze Model and Dark Channel Prior. A specific threshold value is set in the image through Dark Channel Prior(DCP), and based on this, the number of pixels without sea fog is found in the entire image to estimate the sea fog level. Experimental results demonstrate the possibility of estimating the sea fog level using synthetic haze image dataset and real haze image dataset.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.73-82
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• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.725-733
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• 2023

The purpose of this study is to evaluate the effectiveness of virtual grid software (VGS). The purpose of this study is to evaluate the changes in energy and object thickness by dividing the use of VGS into two cases (Without-VGS) without using a movable grid. We attempted to determine the effectiveness of VGS by acquiring images using a chest phantom and a thigh phantom and analyzing SNR and CNR. In the chest phantom and femoral phantom, the tube flow was fixed at 2.5 mAs, and the tube voltage was changed by 10 kVp from 60 to 100 kVp to measure SNR and CNR, and SNR was about 1.09 to 8.86% higher in the chest phantom than in Without-VGS, and CNR was 4.18 to 14.56% higher in the VGS than in Without-VGS. And in the femoral phantom, SNR was about 9.78 to 18.05% higher in VGS than in Without-VGS, and CNR was 21.07 to 44.44% higher in VGS than in Without-VGS. The tube voltage was fixed at 70 kVp in the chest phantom and the femoral phantom, and the amount of tube current was changed at 2.5 to 16 mAs, respectively, and after X-ray irradiation, SNR and CNR were measured in the chest phantom, which was about 1.49 to 11.11% higher in VGS than in Without-VGS, and CNR was 4.76 to 13.40% higher in VGS than in Without-VGS. And in the femoral phantom, SNR was about 2.22 to 17.38% higher in VGS than in Without-VGS, and CNR was 13.85 to 40.46% higher in VGS than in Without-VGS. Therefore, if an inspection is required with a mobile X-ray imaging device, it is believed that good image quality can be obtained by using VGS in an environment where it is difficult to use a mobile grid, and it is believed that the use of mobile X-ray devices can be increased.

• Journal of Chest Surgery
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• v.38 no.5 s.250
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• pp.349-356
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• 2005

Background: Arterial conduits using in coronary artery bypass grafting (CABG) have been known a great long term patency rates, and improved short and long term clinical outcomes. It has been reported that Off pump CABG has better clinical results than CABG using cardiopulmonary bypass. To evaluate the advantage of arterial conduits over venous conduits and to avoid the adverse effects of cardiopulmonary bypass, we performed total arterial Off pump CABG. Material and Method: From January 2001 to October 2004, Off pump CABG using only arterial conduits was performed on 325 patients with a mean age of $59.3\pm11.9$ years ($36\~83$). Mean ejection fraction was $55.4\pm14.0\%\;(15\~86).$ Angiography showed left main disease or triple-vessel disease in $81.9\%$ of the patients. Indications of using arterial conduits was stenosis $\ge50\%$ of left anterior descending artery, stenosis $\ge80\%$ of branches of left circumflex artery, and stenosis $\ge90\%$ of right coronary artery and its branches. Multi-slice computed tomography was performed on 194 patients to evaluate the short term patency rates. Result: A total of 928 distal anastomoses were performed and the average anastomoses per a patient were $2.86\pm0.78$. There was 1 operative mortality. Postoperative complications were mediastinitis in 6 patients ($1.8\%$), renal failure in 4 patients ($1.2\%$), perioperative myocardial infarction in 3 patients ($0.9\%$), reoperation for bleeding in 3 patients ($0.9\%$). There was no postoperative stroke. Patency rate of arterial conduits was $99.3\%$ (581/585). There were 4 stenoses or competitive flows in 2 radial arteries and 2 right internal mammary arteries. Conclusion: Total arterial Off pump CABG appears to be safe, showing a low surgical mortality and morbidity and excellent short term patency rates of arterial conduits.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.101-142
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• 1998

1. Objects The base of classification of Sasang Constitution was the different congenital formation of organs such as lungs, spleen, liver, kidneys, and it was expanded from the viscera region of lungs, spleen, liver, kidneys to the body shape of trunk. The researched about body shape of Sasang Constitution have had points of issues which derived by measurement with hands. But this study was measured the characteristics of body shape putting in importance of anatomical position with the computerized 3-Dimension scanner, which minimized the errors of measurement, and it was abled the cubic measurement such as volume, area of cross section as well as round length. 2. Materials & Method The examinee was healthy male 40 persons and female 20 persons from 20's to 40's, who was diagnosed by the specialist of Sasang Constitutional Medicine. The body shape was measured round length, area of cross section, and volume of 31 anatomical points and the 25 hypothesis with the Rapid 3D Color Scanner Model 3030 RGB/PS. And the characteristics of each constitution's body shape was derived. 3. Results & Concousion In female, Taeumin had the largest trunk and Soeumin had the smallest trunk compared to other constitution, but Soyangin had only the smallest neck. Soeumin has the smallest round length of nipple and the $CV_{12}$, and Soyangin has the smallest breadth of ASIS. Soyangin had the smallest volume from thyroid bone to the highest points of armpits and from sternum to nipple. Taeumin had the largest volume from sternum to the $CV_{12}$ and from sternum to xiphoid process. In male, Taeumin had the largest trunk and Soeumin had the smallest trunk from the level of thyroid bone to ASIS. Soyangin has the longest distance and Soeumin has the shortest distance from nipple to the lowest of breast. Taeumin had the largest volume of trunk and Soeumin had the smallest volume of trunk. In the ration of four-Cho, Taeumin had the longest distance from the highest points of armpits to nipple and Soyangin had the shortest distance of that. Soyangin had the smallest ratio of the height of upper middle cho. Soeumin had the smallest ratio from the $CV_{12}$ to navel among trunk. In the correlation among the four Cho, Taeumin had the negative correlation between the Upper-Cho and the Lower-Middle-Cho significantly.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.124-135
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• 1997

Background : Diffuse panbronchiolitis(DPB) is a disease characterized clinically by chronic cough, expectoration and dyspnea; and histologically by chronic inflammation localized mainly in the region of the respiratory bronchiole. It is prevalent in Japanese, but is known to be rare in Americans and Europians. Only a few cases in Chinese, Italians, North Americans and Koreans have been reported. It is diagnosed by characteristic clinical, radiological and pathologic features. High-resolution CT(HRCT) is known to be valuable in the study of the disease process and response to therapy in DPB. To our knowledge, there has been no correlation of its appearance on HRCT with the severity of the disease process, and radioaerosol scan(RAS) of the lung has not previously been used for the diagnosis of DPB. Method : During recent two years we have found 12 cases of DPB in Kangnam St. Mary's Hospital, Catholic University Medical College. We analysed the clinical characteristics, compared HRCT classifications with clinical stages of DPB, and determined characteristic RAS manifestations of DPB. Results : 1. The ages ranged from 31 to 83 years old(mean 54.5 years old), and male female ratio was 4:8. 75%(9/12) of patients had paranasal sinusitis, and only one patient was a smoker. 2. The patients were assigned to one of three clinical stages of DPB on the basis of clinical findings, sputum bacterology and arterial blood gas analysis. of 12 cases, 5 were in the first stage, 4 were in the second stage, and 3 were in the third stage. In most of the patients, pulmonary function tests showed marked obstructive and slight restrictive impairments. Sputum culture yielded P.aeruginosa in 3 cases of our 12 cases, K.pneumoniae in 2 cases, H.influenzae in 2 cases, and S.aureus in 2 cases. 3. Of 12 patients, none had stage I characteristics as classified on HRCT scans, 4 had slage II findings, 5 had stage III findings, and 3 had stage IV characteristics. 4. We peformed RAS in 7 of 12 patients With DPB. In 71.4% (5/7) of the patients, RAS showed mottled aerosol deposits characteristically in the transitional and intermediary airways with peripheral airspace defects, which contrasted sharply with central aerosol deposition of COPD. 5. There were significant correlations between HRCT stages and clinical stages(r= 0.614, P < 0.05), between HRCT types and Pa02(r= -0.614, P < 0.05), and between HRCT types and ESR(r= 0.618, P < 0.01). Conclusion : The HRCT classifications correspond well to the clinical stage. Therfore in the examination of patients with DPB, HRCT is useful in the evaluation of both the location and severity of the lesions. Also, RAS apears to be a convenient, noninvasive and useful diagnostic method of DPB.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.192-200
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• 2008

To evaluate the hemodynamic changes and the predictive factors of the clinical outcome in pediatric patients with moyamoya disease, we analyzed pre/post basal/acetazolamide stress brain perfusion SPECT with automated volume of interest (VOIs) method. Methods: Total fifty six (M:F = 33:24, age $6.7{\pm}3.2$ years) pediatric patients with moyamoya disease, who underwent basal/acetazolamide stress brain perfusion SPECT within 6 before and after revascularization surgery (encephalo-duro-arterio-synangiosis (EDAS) with frontal encephalo-galeo-synangiosis (EGS) and EDAS only followed on contralateral hemisphere), and followed-up more than 6 months after post-operative SPECT, were included. A mean follow-up period after post-operative SPECT was $33{\pm}21$ months. Each patient's SPECT image was spatially normalized to Korean template with the SPM2. For the regional count normalization, the count of pons was used as a reference region. The basal/acetazolamide-stressed cerebral blood flow (CBF), the cerebral vascular reserve index (CVRI), and the extent of area with significantly decreased basal/acetazolamide- stressed rCBF than age-matched normal control were evaluated on both medial frontal, frontal, parietal, occipital lobes, and whole brain in each patient's images. The post-operative clinical outcome was assigned as good, poor according to the presence of transient ischemic attacks and/or fixed neurological deficits by pediatric neurosurgeon. Results: In a paired t-test, basal/acetazolamide-stressed rCBF and the CVRI were significantly improved after revascularization (p<0.05). The significant difference in the pre-operative basal/acetazolamide-stressed rCBF and the CVRI between the hemispheres where EDAS with frontal EGS was performed and their contralateral counterparts where EDAS only was done disappeared after operation (p<0.05). In an independent student t-test, the pre-operative basal rCBF in the medial frontal gyrus, the post-operative CVRI in the frontal lobe and the parietal lobe of the hemispheres with EDAS and frontal EGS, the post-operative CVRI, and ${\Delta}CVRI$ showed a significant difference between patients with a good and poor clinical outcome (p<0.05). In a multivariate logistic regression analysis, the ${\Delta}CVRI$ and the post-operative CVRI of medial frontal gyrus on the hemispheres where EDAS with frontal EGS was performed were the significant predictive factors for the clinical outcome (p =0.002, p =0.015), Conclusion: With probabilistic map, we could objectively evaluate pre/post-operative hemodynamic changes of pediatric patients with moyamoya disease. Specifically the post-operative CVRI and the post-operative CVRI of medial frontal gyrus where EDAS with frontal EGS was done were the significant predictive factors for further clinical outcomes.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.1
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• pp.21-32
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• 2010

The convergence angle of a prepared tooth is a very important factor in the retention and resistance of a crown restoration. But various intraoral environments and clinician's techniques make it difficult to obtain the ideal inclination. Therefore, in this study, clinical convergence angle of a prepared tooth was investigated. The data was collected from the patient models of prosthodontic residents and the patient models of general practitioners. The images of mesiodistal and buccolingual surfaces were taken with a digital camera to evaluate the convergence angle on 'ImageJ' program. The images were classified according to the criteria (1. Clinician group, 2. Position in the dental arch, 3. The purpose of abutment preparation)and then analyzed. The mean convergence angle of a prepared tooth for Korean clinicians was $15.02^{\circ}$ (${\pm}10.13^{\circ}$). 1. It was significant in the convergence angle between the general practitioner group and the prosthodontic resident group(p<0.05). 2. It was significant between the mesiodistal and buccolingual surface in the the prosthodontic resident group(p<0.05). 3. For the general practitioner group, it was significant when anteriors and premolars were compared with molars(p<0.05). For the prosthodontic resident group, it was significant when anteriors and premolars were compared with molars (p<0.05). 4. When divided into upper and lower arches, for the general practitioner group, it showed significant difference in the buccolingual aspect(p<0.05). Also in the prosthodontic resident group, it showed significant difference in the buccolingual aspect(p<0.05). 5. Dividing left and right sides of the arches, there was no significant difference in the general practitioner group and the prosthodontic resident group(p>0.05). 6. In the general practitioner group, it was significant in the mesiodistal axial convergence angle of single crown abutment and 3 unit bridge abutment(p<0.05). In the prosthodontic resident group, it was significant in the mesiodistal and overall axial convergence angle of single crown abutment and 3 unit bridge abutment(p<0.05). Clinical convergence angle of prepared tooth in Korea was included in agreement with other studies investigating convergence angle that ranged from 10 to 22 degrees, achieved in clinical practice.

• The Korean Journal of Nuclear Medicine
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• v.37 no.2
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• pp.83-93
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• 2003

Background: Lung-to-heart uptake ratio (LHR) in $^{201}Tl-chloride$ myocardial perfusion scan is believed to be a reliable marker for left ventricular (LV) dysfunction, but the clinical value of LHR is controversial for $^{99m}Tc-MIBI$ imaging. Furthermore, most of results suggesting lung uptake of $^{99m}Tc-MIBI$ as a potential marker for LV dysfunction used immediate post-stress images, instead of routine images acquired 1 hour after tracer injection. The goal of our study was to investigate whether LHR evaluated with routine gated $^{99m}Tc-MIBI$ imaging can reflect the degree of perfusion defect or left ventricular performance. Subjects and Methods: 241 patients underwent exercise $^{99m}Tc-MIBI$ myocardial SPECT were classified into normal myocardial perfusion (NP, n=135) and abnormal myocardial perfusion (AP, n=106) group according to the presence of perfusion defect. LHR was calculated from anterior projection image taken at 1-hour after injection. Two legions of interest (ROIs) were placed on left lung above LV and on myocardium showing the highest radioactivity. Subjects were classified by left ventricular ejection fraction (LVEF), as Gr-I: >50%, Gr-II: 36-50%, Gr-III: <36% and by summed stress score (SSS), as Gr-A: <4, Gr-B: 4-8, Gr-C: 9-13, Gr-D: >13, LHR was compared among these groups. Results: In NP group(n=135), LHR, were higher in men than women ($men:\;0.311{\pm}0.03,\;women:\;0.296{\pm}0.03,\;p<0.05$). Significant difference, in LHR were found between NP and AP groups both for men and women ($men:\;0.311{\pm}0.03\;vs\;.\;0.331{\pm}0.06,\;women:\;0.296{\pm}0.03\;vs.\;0.321{\pm}0.07.\;p<0.05$). There were weak negative correlation between LHR and LVEF (r=-0.342, p<0.05) and weak positive correlation between LHR and SSS (r=0.478, p<0.05) in men, but not in women (LVEF: r=-0.279, p=0.100, SSS: r=0.276, p=0.103). Increased LHR was defined when for more than mean + 2SD value ($men{\geq}0.38,\;women{\geq}0.37$) of the LHR of the subject with normal perfusion. Increased LHR were observed more frequently in subjects with lower LVEF (Gr-I: 11.1%, Gr-II: 27.0%, Gr-III: 35.4%, p<0.05) and higher SSS(Gr-A: 14.0%, Gr-B: 5.7%, Gr-C: 18.2%, Gr-D: 40.7%, p<0.05). Conclusions: LHRs obtained from routine $^{99m}Tc-MIBI$ gated SPECT images were weakly correlated with LVEF and perfusion defect. Although significant overlaps were observed between normal and abnormal perfusion group, LHRs could be used as an indirect marker of severe perfusion defect or reduced left ventricular function.