• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.1-8
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• 2007

In this paper, research on joint optimization of the image spatial registration and the exposure compensation is conducted. The exposure compensation is performed in a frame work of the intensity compensation based on the polynomial approximation of the relationship between images. This compensation is jointly combined with the registration problem employing the Gauss-Newton nonlinear optimization method. In this paper, to perform for a simple and stable optimization, the block-coordinate method is combined with the Gauss-Newton optimization and extensively compared with the traditional approaches. Furthermore, regression analysis is considered in the compensation part for a better stable performance. By combining the block-coordinate method with the Gauss-Newton optimization, we can obtain a compatible performance reducing the computational complexity and stabilizing the performance. In the numerical result for a particular image, we obtain a satisfactory result for 10 repeats of the iteration, which implies a 50% reduction of the computational complexity. The error is also further reduced by 1.5dB compared to the ordinary method.

• Toxicological Research
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• v.35 no.2
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• pp.137-154
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• 2019

Triclosan (TCS) is an antimicrobial compound used in consumer products. The purpose of current study was to examine toxicology and risk assessment of TCS based on available data. Acute toxicities of oral, transdermal and inhalation routes were low, and phototoxicity and neurotoxicity were not observed. Topical treatment of TCS to animal caused mild irritation. TCS did not induce reproductive and developmental toxicity in rodents. In addition, genotoxicity was not considered based on in vitro and in vivo tests of TCS. It is not classified as a carcinogen in international authorities such as International Agency for Research on Cancer (IARC). No-observed-adverse-effect level (NOAEL) was determined 12 mg/kg bw/day for TCS, based on haematoxicity and reduction of absolute and relative spleen weights in a 104-week oral toxicity study in rats. Percutaneous absorption rate was set as 14%, which was human skin absorption study reported by National Industrial Chemicals Notification and Assessment Scheme (NICNAS) (2009). The systemic exposure dosage (SED) of TCS has been derived by two scenarios depending on the cosmetics usage of Koreans. The first scenario is the combined use of representative cosmetics and oral care products. The second scenario is the combined use of rinse-off products of cleansing, deodorants, coloring products, and oral care products. SEDs have been calculated as 0.14337 mg/kg bw/day for the first scenario and 0.04733 mg/kg bw/day for the second scenario. As a result, margin of safety (MOS) for the first and second scenarios was estimated to 84 and 253.5, respectively. Based on these results, exposure of TCS contained in rinse-off products, deodorants, and coloring products would not pose a significant health risk when it is used up to 0.3%.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.4
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• pp.192-198
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• 2019

Objectives: Oral and maxillofacial surgeons must gain mastery of various approaches to the midface due to the increasing incidence, complexity, and severity of presenting midfacial fractures. Unlike in the case of other body parts, the need to preserve facial aesthetics makes it more difficult for the surgeon to select an approach for managing the facial injuries. The midfacial degloving (MFD) approach is a combination of intraoral and intranasal incisions made to access the midface without any external incision. The aim of the present study was to evaluate the efficacy of MFD in maxillofacial surgery and to assess its advantages and complications. Materials and Methods: The MFD approach was used in five cases, with three cases treated with open reduction and internal fixation and two cases operated on for posttraumatic deformity. Nasal dorsum augmentation was completed in three cases and nasal osteotomy was performed in one case. The bicoronal flap technique was combined with MFD for frontal bone augmentation in one case. The intraoperative time required for flap completion and the ease of performing the planned procedures were noted. Postoperative evaluation was done for reduction, aesthetics, function, and complications. Results: Access was excellent for performing all planned procedures. Average time spent for flap elevation and exposure of the midface was 63 minutes. Complications like postoperative swelling, infraorbital nerve paresthesia, and intranasal crusting were all transient. No long-term complications like stenosis of the nose, sneer deformity, or weakness of the facial muscles were noticed. Additionally, no complications were noted when MFD was combined with bicoronal flap. Conclusion: Though the MFD approach is technically demanding and takes more time than other facial approaches, it should be learned and applied by maxillofacial surgeons in selective cases, as it provides complete exposure of the midface without facial scarring.

• Journal of the Ergonomics Society of Korea
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• v.31 no.3
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• pp.445-453
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• 2012

The aim of this paper was to prove that if the risk level in combined tasks was improved through evaluation of postural load of liquid weight measurement process, the workload level and ratio of exposure time would be changed, and the time of process would be seen concurrently. Background: According to results of epidemiological studies conducted by Korea Occupational Safety & Health Agency, 122 musculoskeletal disorders occurred during 1992 to 2008, in which manufacturing industry covers 96(78.7%) of total. However, this is an insufficient level and only occupies 39% based on the South Korea's manufacturing standard industrial classification(246 industries). Method: Firstly, the number of batches weighed on one day(460min) was investigated based on the work performed and Weight measured weekly. VCR recording was taken based on the level of liquid ingredients prescribed for 1batch using the Camcorder. After dividing a 356 sec video into 1 sec using the screen capture function in Gom player, the job classification was performed by analyzing the change of working postures, which revealed 148 working postures. Time measurement was decided by time of the postures was being maintained. Then, the REBA analysis was performed for the working postures. The ratio of Exposure time was calculated based on the measurement time and REBA Score. In addition, the recommendations were designed and implementation was carried out for the working postures with REBA Score higher than 3. Finally, after the intervention, REBA measurement, time measurement, and ratio of exposure time were calculated for the comparison of works before and after improvement. Results: The number of work elements was decreased by 30.4% from 148 to 103 after improvement. The results of time measurement showed that the time was reduced by 46.3% from 356 sec to 191 sec. And the ratio of exposure time was also improved by 52.1% from 0% to 52.1% after improvement. Conclusion: The reduction of time was found to improve the productivity of management. Furthermore, because the reduction of ratio of exposure time and the improvement of workload level are the improvement of discomfort, it would contribute to the improvement of the worker's psychological working posture. Application: These results would contribute to musculoskeletal disease prevention and management performance. Further studies for other industries would be needed based on this case study.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.490-499
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• 2002

Recently, gamma radiographic equipments have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of $0.4{\sim}1.2m/s$ by BLDC motor of 24V 200W which has output of $54kgf{\cdot}cm$, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.381-392
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• 2022

Objectives: Objective of this study is to review briefly exposure characteristics, monitoring instruments and threshold limit values for extremely low frequency-magnetic field (ELF-MF) methods. This study was undertaken through brief literature review. We performed a literature search in PubMed to identify ELF-MF studies conducted in workplaces. Initial search keywords such as 'extremely low frequency-magnetic field (ELF-MF)' and 'electromagnetic fields (EMF)' combined or singly. We limited our review to occupational rather than general nonworkplace environmental exposures. Methods: The contents we reviewed: key industry and occupations generating ELF-MF, several direct-reading instruments monitoring ELF-MF and threshold limit values (TLV) preventing health effects may be caused by the exposure to ELF-MF. Results: The industries related to the generation and supply of electricity, electrolytic installations, welding, and induction heating and more were regarded as high ELF-MF exposure industries. All jobs handling or employed performed in power cable lines, electrical wiring, and electrical equipment are found to be exposed to ELF-MF. Threshold or ceiling limit, 1,000 µT, is established to prevent acute effects of exposure to low-frequency EMFs on the nervous system: the direct stimulation of nerve and muscle tissues and the induction of retinal phosphenes. The International Agency for Research on Cancer (IARC) has classified ELF-MF as possibly carcinogenic to humans chiefly based on epidemiological studies on childhood leukemia. However, a causal relationship between magnetic fields and several types of cancer including childhood leukemia has not been established nor has any other long-term effects. Risk management using precautionary measures, has been initiated by the US and EU to prevent chronic health effects related to ELF-MF exposure in workplaces. Conclusion: This study recommends the implementation of various measures such as theestablishment of occupational exposure limit values for ELF-MF and precautionary principle to prevent potential chronic occupational health effects may be caused by ELF-MF in Korea.

• Journal of Acupuncture Research
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• v.31 no.4
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• pp.71-79
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• 2014

Objectives : The aim of this study is to evaluate the safety of acupuncture therapy when applied to patients who are undergoing anticoagulants / antiplatelet medication therapy combined with herbal medicine using a retrospective, case-control study. Methods : 428 charts of patients were reviewed in this study. Odds ratio between case of bleeding-related adverse event and control was calculated as main analysis. Exposures were anticoagulants / antiplatelet medication, Hwalhyeolgeoeo herbal medicine and combination of both drugs. Additionally, odds ratios were calculated according to the severity of bleeding-related adverse events. Results : The results were as following: 1. Analysis of all bleeding-related adverse events showed there was no increased risk of combined therapy compared with other exposures and control group. 2. Analysis of only clinically significant adverse events showed there was no increased risk of combined therapy compared with other exposure and control group. 3. Hwalhyeolgeoeo herbal medicine group showed a tendency of increased risk of bleeding-related adverse events in all analysis but was not statistically significant. Conclusions : The results suggest that Hwalhyeolgeoeo herbal medicine-anticoagulant / antiplatelet medication combined therapy may not increase risk of bleeding-related adverse events in acupuncture therapy. By executing various modules of analysis, it was possible to acquire useful data for possible future studies. Further research is needed to confirm such results.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.71-76
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• 1998

Exposure to environmental toxicants can cause cellular problems including the interference of DNA repair processes which may lead to the development of cancer. The existence of toxicant-induced DNA repair abnormality was investigated using mice exposed in vivo to genotoxic chemicals and then challenging their exposed lymphocytes in vitro with bleomycin. The repair of bleomycin-induced DNA damage as estimated by the frequency of chromosome aberrations was determined. Our data indicates that the observed aberration frequencies after in vivo exposure to N-methyl-N'-nitro-N-nitnsoguanidine (MNNG) and in vitro challenge with bleomycin are consistently higher than expected. The enhanced response is not due to the induction of chromosome damage by 25 or 50 mg/kg MNNG since the chemical did not cause chromosome aberrations in lymphocytes of these mice. The observed response after the combined exposure to benzo[a]pyrene (BP) and bleomycin was significantly lower than expected with low in vivo doses of BP (50 mg/kg) and then significantly higher than expected with the high doses (200 mg/kg). We interpret our data to indicate that in vivo exposure to genotoxic agents can cause abnormal DNA repair activities. The response is, however, independent of the clastogenic activities of the inducing chemicals, but dependent upon the inducing agents and on the exposure doses.

• The Korean Journal of Physiology
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• v.6 no.1
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• pp.11-18
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• 1972

In an attempt to observe the Possible radioprotective actions of single or combined application of reduced glutathione (GSH) and cold exposure in mammals, the albino mouse was subjected to GSH injection, cold exposure at $-1{\pm}0.2C$ and whole-body X-irradiation with 900r either singularly or in combination, or the X-irradiation following the cold exposure and/or GSH injection. The levels of intrinsic NP-SH and NP-SS of the liver, brain and heart were measured at one hour after each application, and the results were compared with the control, i.e., non-irradiated and non-cold exposed normal animal. NP-SH was measured by the Ellman's method, and NP-SS was measured by the electrolytic reduction method described by Dohan and Woodward. The results thus obtained are summarized as follows: 1) The levels of NP-SH in the liver, brain and heart of the normal mouse was $6.35{\pm}0.61,\;2.65{\pm}0.15\;and\;3.17{\pm}0.10{\mu}\;mol/gm\;wet\;wt.$, respectively, and NP-SS was $3.09{\pm}0.11,\;2.95{\pm}0.20\;and\;0.18{\pm}0.24{\mu}\;mol/gm\;wet\;wt.$, respectively. 2) Though there were some degrees of difference among the tissues studied, a general tendency of (1) elevated NP-SH and NP-SS levels in the GSH injection group, (2) similar or slightly elevated NP-SH and NP-SS levels in the cold-exposed group, and (3) markedly decreased levels of NP-SH and NP-SS in the X-irradiated group, was observed. When GSH was injected prior to the X-irradiation, NP-SH and NP-SS in all the tissues studied showed generally higher values than in the group where the X-irradiation was given alone, and the values were close to the normal. In the group where the cold exposure was applied immediately after the X-irradiation, no significant difference was observed in the NP-SH and NP-S5 levels comparing with the X-irradiation group. On the contrary, when GSH was injected immediately prior to the X-irradiation or cold exposure, NP-SH and NP-SS levels were either similar to, or higher than, the normal value.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1519-1526
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• 2010

Serum lipid (SL) is a commercially available cholesterol-rich, proteinaceous compound extracted from bovine serum. Here we investigated the adipogenic transdifferentiation potential of SL on bovine myogenic satellite cells. Exposure of satellite cells to SL could generate lipid droplets on day 2, and further exposure to SL increased cytoplasmic lipid accumulation giving adipocyte morphology. The expression analysis of PPAR gamma and GPDH adipocyte markers along with Oil-red-O staining results confirmed the transdifferentiation potential of SL. When cells were treated at different concentrations (5, 10, 20, $40{\mu}l$/ml) of SL, the results indicated that even levels as low as $5{\mu}l$ SL /ml could induce transdifferentiation, and maximum induction was obtained at $20{\mu}l$ SL/ml. After treatment with SL at different concentrations the expression levels of PPAR gamma varied significantly (p<0.05), whereas the expression of other adipogenic transcription factors showed no difference, indicating that SL acts through PPAR gamma. The combined effect of SL and troglitazone proved to be the best combination for induction of transdifferentiation compared to the individual effect of SL or troglitazone. Thus, overall results clearly show that SL induces transdifferentiation of bovine myogenic satellite cells to adipocytes.