• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.111-121
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• 2007

Diagnosis and Prediction of urban industrial structure is a key subject for establishment of sustainable urban development plan. By this time, studies of industry-related urban spatial structure have been concentrated on measurement of space distribution by industry type mainly using data about urban industries or total worker numbers. Now, status of workers become an important issue so this study analyzed qualitative change of urban industrial structure in the view of space using work status classification system. For that, data for work status in 1994 and 2004 were collected in towns and villages, and space analysis units were coincided based on change data between 1994 and 2004. Then, it analyzed spatial distribution pattern of employment through qualitative standard called work status using GIS. The analysis results by work status type of Busan industrial structure in GIS circumstance were as below. First, traditional labor intensive industries met a limit and service and wholesale/retail sale industries went to be poor livelihood. Therefore, Busan's employment rate should be decreased and worker numbers were statistically increased, however, irregular and non-wage workers were suddenly increased. So, it was determined that the quality of employment in Busan area came down. Second, a traditional downtown area has dwindled; on the other hand, employment has been increased in new town or new industrial complex and in the area developed services rather than the manufacturing industry. It is expected that the result of this study may be meaningful as data to prepare for longterm industrial development plan through qualitative evaluation called work status as well as to make behavior pattern of industrial structure which is basis of urban development.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.357-360
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• 1997

For medical students and doctors, knowledge of the 3-dimensional (3D) structure of the heart is very important in diagnosis and treatment of the heart diseases. 2-dimensional (2D) tools (e.g. anatomy book) or classical 3D tools (e.g. plastic model) are not sufficient or understanding the complex structures of the heart. Moreover, it is not always guaranteed to dissect the heart of cadaver when it is necessary. To overcome this problem, virtual dissection systems of the heart have been developed. But these systems are not satisfactory since they are made of radiographs; they are not true 3D images; they can not be used to dissect freely; or they can only be operated on the workstation. It is also necessary to make the dissection systems incorporating the various races and tribes because of the organ's difference according to race and tribe. This study was intended to make the 3D image of the heart from a Korean cadaver, and to establish a virtual dissection system of the heart with a personal computer. The procedures or manufacturing this system were as follows. 1. The heart from a Korean adult cadaver was embedded with gelatin solution, and serially cross-sectioned at 1mm-thickness on a meat slicer. Pictures or 153 cross-sectioned specimens were inputted into the computer using a digital camera ($756{\times}504$ resolution, true color). 2. The alignment system was established by means of the language of IDL, and applied to align 2D images of the heart. In each of 2D images, closed curves lining clean and dirty blood pathways were drawn manually on the CorelDRAW program. 3. Using the language of IDL, the 3D image and the virtual dissection system of the heart were constructed. The virtual dissection system of the heart allowed or ree rotation, any-directional sectioning, and selected visualization of the heart's structure. This system is expected to become more advanced, and to be used widely through Internet or CD-title as an educational tool for medical students and doctors.

• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.67-72
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• 2015

In diagnostic radiology, the use of automatic exposure control device is internationally recommended for diagnosis and optimization. However, if exposed to prolonged radiation is a complicated manufacturing process, there is a problem that occurs decrease of various performance overall brightness sensor, which is commercially available conventional. Therefore, in this study, absorption of X-ray is high, and I want to evaluate the AEC applicability of the sensor of the photoconductor-based production has an easy advantage. Experimental results confirms the possibility of fabrication of the sensor through an increase in the SNR, with the detection efficiency superior, accurate turn-off. In addition, it is confirmed that the experimental results of the transmittance and the latent image, Ghost effect by the light conductor does not appear, in the case of a photoconductor with the exception of the PbO, 80% - and it was confirmed good transmittance of 90%. Therefore, excellent mechanical stability and poor performance due to a change of the doping concentration than the existing products that have been put to practical use, the sensor easy photoconductor based, fabrication and can be applied as AEC sensor is expected.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.263-275
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• 2022

The loss of posterior occlusal support leads to further complications such as collapsed occlusal plane and reduced vertical dimension, and it may cause problems such as facial appearance change, reduced chewing efficiency, and temporomandibular joint disorders. In such case, it is necessary to re-establish occlusal plane and vertical dimension properly through accurate diagnosis and predictable treatment plan. This case report presents a 71-year-old female, whose occlusal plane was collapsed and posterior restorative space was insufficient. To perform a patient-friendly full mouth rehabilitation, proper vertical dimension and occlusal plane were decided by evaluation of interocclusal space at her physiologic mandibular rest position, swallowing, pronunciation, facial appearance, and the average length of anterior teeth. And then, the fixed provisional restorations were fabricated with the new occlusal position, and evaluated for 5 months with checking adaptation of masticatory muscles and any kind of clinical symptoms occurs or not. After confirmation of functional stability and esthetic satisfaction with the newly established occlusion, final definitive restorations were fabricated and inserted in the mouth. Through the above process, the treatment result was functionally and aesthetically satisfactory.

• Design & Manufacturing
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• v.17 no.1
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• pp.20-26
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• 2023

Lab-on-a-disc is a circular disc shape of cartridge that can be used for blood-based liquid biopsy to diagnose an early stage of cancer. Currently, liquid biopsies are regarded as a time-consuming process, and require sophisticated skills to precisely separate cell-free DNA (cfDNA) and circulating tumor cells (CTCs) floating in the bloodstream for accurate diagnosis. However, by applying the lab-on-a-disc to liquid biopsy, the entire process can be operated automatically. To do so, the lab-on-a-disc should be designed to prevent blood leakage during the centrifugation, transport, and dilution of blood inside the lab-on-a-disc in the process of liquid biopsy. In this study, the main components of lab-on-a-disc for liquid biopsy are fabricated by injection molding for mass production, and ultrasonic welding is employed to ensure the bonding strength between the components. To guarantee accurate ultrasonic welding, the flatness of the components is optimized numerically by using the response surface methodology with four main injection molding processing parameters, including the mold & resin temperatures, the injection speed, and the packing pressure. The 27 times finite element analyses using Moldflow® reveal that the injection time and the packing pressure are the critical factors affecting the flatness of the components with an optimal set of values for all four processing parameters. To further improve the flatness of the lab-on-a-disc components for stable mass production, a quarter-disc shape of lab-on-a-disc with a radius of 75 mm is used instead of a full circular shape of the disc, and this significantly decreases the standard deviation of flatness to 30% due to the reduced overall length of the injection molded components by one-half. Moreover, it is also beneficial to use a quarter disc shape to manage the deviation of flatness under 3 sigma limits.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.58-71
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• 2015

Objectives: The aims of this study were to investigate the classification system of chemical substances in the Occupational Safety and Health Act(OSHA) and Chemical Substances Control Act(CSCA) and to compare several health indices (i.e., Time Weighted Average (TWA), Lethal Dose ($LD_{50}$), and Lethal Concentration ($LC_{50}$) of chemical substances by categories in each law. Methods: The chemicals regulated by each law were classified by the specific categories provided in the respective law; seven categories for OSHA (chemicals with OELs, chemicals prohibited from manufacturing, etc., chemicals requiring approval, chemicals kept below permissible limits, chemicals requiring workplace monitoring, chemicals requiring special management, and chemicals requiring special heath diagnosis) and five categories from the CSCA(poisonous substances, permitted substances, restricted substances, prohibited substances, and substances requiring preparation for accidents). Information on physicochemical properties, health indices including CMR characteristics, $LD_{50}$ and $LD_{50}$ were searched from the homepages of the Korean Occupational and Safety Agency and the National Institute of Environmental Research, etc. Statistical analysis was conducted for comparison between TWA and health index for each category. Results: The number of chemicals based on CAS numbers was different from the numbers of series of chemicals listed in each law because of repeat listings due to different names (e.g., glycol monoethylether vs. 2-ethoxy ethanol) and grouping of different chemicals under the same serial number(i.e., five different benzidine-related chemicals were categorized under one serial number(06-4-13) as prohibited substances under the CSCA). A total of 722 chemicals and 995 chemicals were listed at the OSHA and its sub-regulations and CSCA and its sub-regulations, respectively. Among these, 36.8% based on OSHA chemicals and 26.7% based on CSCA chemicals were regulated simultaneously through both laws. The correlation coefficients between TWA and $LC_{50}$ and between TWA and $LD_{50}$, were 0.641 and 0.506, respectively. The geometric mean values of TWA calculated by each category in both laws have no tendency according to category. The patterns of cumulative graph for TWA, $LD_{50}$, $LC_{50}$ were similar to the chemicals regulated by OHSA and CCSA, but their median values were lower for CCSA regulated chemicals than OSHA regulated chemicals. The GM of carcinogenic chemicals under the OSHA was significantly lower than non-CMR chemicals($2.21mg/m^3$ vs $5.69mg/m^3$, p=0.006), while there was no significant difference in CSCA chemicals($0.85mg/m^3$ vs $1.04mg/m^3$, p=0.448). $LC_{50}$ showed no significant difference between carcinogens, mutagens, reproductive toxic chemicals and non-CMR chemicals in both laws' regulated chemicals, while there was a difference between carcinogens and non-CMR chemicals in $LD_{50}$ of the CSCA. Conclusions: This study found that there was no specific tendency or significant difference in health indicessuch TWA, $LD_{50}$ and $LC_{50}$ in subcategories of chemicals as classified by the Ministry of Labor and Employment and the Ministry of Environment. Considering the background and the purpose of each law, collaboration for harmonization in chemical categorizing and regulation is necessary.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.300-307
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• 2017

Electroencephalography (EEG) is distinct from other medical imaging tests in that it is a functional test that helps to diagnosis disorders related to the brain, such as epilepsy. The most important abilities for a medical technologist when performing an EEG are knowing the exact location of the electrode and recording the EEG wave clearly, except for artifacts. Although theoretical education and practical training are both included in the curriculum for improving these abilities, sufficient practical training has been lacking due to problems like expensive equipment and insufficient practical training time. We try to solve these issues by manufacturing the training 10-20 electrode system and by estimating the efficiency and satisfaction of the training 10-20 electrode system through a questionnaire. The time required for practical training using this system was $43.58{\pm}9.647min$, which proved to be efficient. The satisfaction score of participants who experienced curriculum practical training was improved from $7.21{\pm}2.285$ to $9.46{\pm}1.166$. Based on these findings, it is considered that practical training via the use of the training 10-20 electrode system will solve the problems, such as lack of equipment and insufficient practical training time. Nonetheless, to further improve the training 10-20 electrode system, it must overcome the limitations of developing a device capable of checking the actual brain waves and validating the exact location of electrode attachment.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.101-105
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• 2011

Purpose: Estradiol in the menstrual cycle and ovulation induction as an important test of currently national nuclear medicine laboratory in the normal patients and patients with infertility tests are being performed. For the diagnosis of menopause is an important test with follicle stimulating hormone (FSH) and Luteinizing hormone (LH). Currently participating in external quality control of the nation's hospitals that is 54 percent of 37 hospitals, 20 hospitals have been using A's reagent. The kit's test results are highly different from other kit comes with the test results of specimens have been found. And for the phenomenon is to study the problem. Materials and Methods: Estraiol test were referred to our hospital which results of samples as more than 100pg/ml 75 specimens measured by radioimmunoassay(RIA) test with company A company B company C company D Kit, Chemiluminescent assay (CMIA) to examine and compare to the results from april to August in 2010. Results: Kit for each manufacturing company as measured by the results obtained using the average value of the correlation coefficient (R2) and A company 0.8906 B 0.9527 C 0.9547 and D company correlation coefficient of 0.873 showed a good correlation that measuring the results of A company high concentrations when Company B Company C Company D with CMIA test concentrations measured low results that the two cases were discovered specimens. Conclusion: Most of the test results of 75 samples came up with a similar trend, but two cases were reported in the patients very differently. A company result reported higher than 700 pg/ml, while the rest of other test results report was approximately 10 pg/ml. The common point of two samples more than 50 years patients are estimated to be diagnosed with cancer in postmenopausal patients receiving treatment and levels of FSH were found to be greater than 50 mIU/ml. Did not identify the exact cause. I suggest if you are using A company kit that need to again check when Estradiol result and follicle stimulating hormone results is higher.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.84-89
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• 2013

Purpose: Patients' movement during long image acquisition time for the fusion image of PET-CT (Positron Emission Tomography-Computed Tomography) results in unconformity, and greatly affects the quality of the image and diagnosis. The arm support fixtures provided by medical device companies are not manufactured considering the convenience and safety of the patients; the arm and head movements (horizontal and vertical) during PET/CT scan cause defects in the brain fundus images and often require retaking. Therefore, this study aims to develop patient-compensation device that would minimize the head and arm movements during PET/CT scan, providing comfort and safety, and to reduce retaking. Materials and Methods: From June to July 2012, 20 patients who had no movement-related problems and another 20 patients who had difficulties in raising arms due to shoulder pain were recruited among the ones who visited nuclear medicine department for PET Torso scan. By using Patient Holding System (PHS), different range of motion (ROM) in the arm ($25^{\circ}$, $27^{\circ}$, $29^{\circ}$, $31^{\circ}$, $33^{\circ}$, $35^{\circ}$) was applied to find the most comfortable angle and posture. The manufacturing company was investigated for the permeability of the support material, and the comfort level of applying bands (velcro type) to fix the patient's head and arms was evaluated. To find out the retake frequency due to movements, the amount of retake cases pre/post patient-compensation were analyzed using the PET Torso scan data collected between January to December 2012. Results: Among the patients without movement disorder, 18 answered that PHS and $29^{\circ}$ arm ROM were the most comfortable, and 2 answered $27^{\circ}$ and $31^{\circ}$, respectively. Among the patients with shoulder pain, 15 picked $31^{\circ}$ as the most comfortable angle, 2 picked $33^{\circ}$, and 3 picked $35^{\circ}$. For this study, the handle was manufactured to be adjustable for vertical movements. The material permeability of the patient-compensation device has been verified, and PHS and the compensation device were band-fixed (velcro type) to prevent device movements. A furrow was cut for head fixation to minimize the head and neck movements, fixing bands were attached for the head, wrist, forearm, and upper arm to limit movements. The retake frequency of PET Torso scan due to patient movements was 11.06% (191 cases/1,808 patients) before using the movement control device, and 2.65% (48 cases/1,732 patients) after using the device; 8.41% of the frequency was reduced. Conclusion: Recent change and innovation in the medical environment are making expensive medical image scans, and providing differentiated services for the customers is essential. To secure patient comfort and safety during PET/CT scans, ergonomic patient-compensation devices need to be provided. Therefore, this study manufactured a patientcompensation device with vertically adjustable ergonomic ROM according to the patient's body shape and condition during PET Torso scan. The defects in the basal ganglia images due to arm movements were reduced, and retaking was decreased.