• 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.

• Safety and Health at Work
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• v.12 no.3
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• pp.370-376
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• 2021

Backround: Working condition surveys are widely recognized as useful tools for monitoring the quality of working life and the improvements introduced by health and safety policy frameworks at the European and national level. The Italian Workers' Compensation Authority carried out a national survey (Insula) to investigate the employer's perceptions related to working conditions and their impact on health. Methods: The present study is based on the data collected from the Italian survey on health and safety at work (INSULA) conducted on a representative sample of the Italian workforce (n = 8,000). This focuses on the relationship between psychosocial risk factors and self-reported health using a set of logistic and linear regression models. Results: Working conditions such as managerial support, job satisfaction, and role act as protective factors on mental and physical health. On the contrary, workers' risk perceptions related to personal exposure to occupational safety and health risks, concern about health conditions, and work-related stress risk exposure determine a poorer state of health. Conclusions: This study highlights the link between working conditions and self-report health, and this aims to provide a contribution in the field of health at work. Findings show that working conditions must be object of specific preventive measures to improve the workers' health and well-being.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.5
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• pp.91-96
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• 2010

In the various disaster scene effective protective equipment and suppression measures of crisis response cases that is closed all in Korea. Due to asbestos exposure by wearing protective equipment, as well as thoroughly strengthen firefighting, recognize the seriousness of the hazard factors in the fire activity, and established legal system for disease compensation and supplemented by institutional for diseases not yet recognized by officially recognized disaster, fire officials to improve morale and working conditions can be expected to improve major public service.

• Korean Journal of Digital Imaging in Medicine
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• v.3 no.1
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• pp.76-84
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• 1997

We tried to find any factor to reduce the exposure dose with ST-VA type generator which has the higher exposure dose. The guideline recommended by the provisions of IAEA regulation is being used at the time of radiation exposure and almost of those equipments used for this study had less amount of doses than those in the guideline. The FCR may be possible to decrease a certain amount of dose with effective applications of it's automatic image compensation utilities and the verifying function in PACS. Next time, it is required to add a great number of hospitals for wide range of studios and measurements, and make standard exposure Control table which will bing in practice, material decrease of dose volumes when radiation exposure.

• Transactions of the Society of Information Storage Systems
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• v.6 no.2
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• pp.63-67
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• 2010

Holographic data storage system is one of next generation high density optical memories. Thereby storing multiple data pages using multiplexing method in one spot, we can achieve high store density and fast access time. However, for uniform writing, we must control exposure time properly by the change of writing material characteristics. Many studies have been investigated about exposure time scheduling. However, once it is decided, we cannot change the scheduled time. Therefore, it is hard to obtain uniform data intensity. In this study, we propose exposure time control method using additional red beam as the monitoring signal. Through reconstructed red beam intensity in real time, we can adjust exposure time by the writing condition change. We construct compensation method mathematically and verify the feasibility of proposed method through the experiments.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.325-336
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• 1997

The purpose of this study was to evaluate the compensation effect of exposure duration increase to decreased light intensity of visible-light curing unit. The specimen with 2mm thickness was made of Restorative $Z-100^{TM}$ (A2 shade, 3M Dental Products, U.S.A.) and cured with $Optilux^{TM}$ (Demetron Research Co. U.S.A.). The light intensity was controlled to 420 $mW/cm^2$, 540 $mW/cm^2$, 630 $mW/cm^2$ and curing time, also, controlled to 40, 60, 80 seconds. Cured specimen was stored in a light-proof container for 24 hours to post-irradation was completed. Microhardness of top and bottom surface of specimen were measured to evaluate the depth of cure. The obtained results were as follows: 1. The microhardness of top and bottom surface of the composite resin specimen was increased significantly as light intensity and exposure time was increased (P<0.01). 2. Light intensity was more correlated with bottom microhardness(${\gamma}{\geq}$0.438) than top microhardness(${\gamma}{\geq}$0.213), and exposure time was more correlated with top microhardness (${\gamma}{\geq}$0.424) than bottom microhardness(${\gamma}{\geq}$0.335). 3. The regressive equation was obtained in this study as follows : $H=0.07{\times}D+0.012{\times}I+76$ (H : Microhardness(KHN), D : Exposure time, I : Light intensity)

• Journal of Environmental Health Sciences
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• v.35 no.5
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• pp.426-432
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• 2009

Asbestos is a commercial term of natural occurring silicated minerals and forms long, thin fibers. Chrysotile, the serpentine asbestos, accounts for most use in commercial use. Asbestos is well known health hazard material and it is proved that inhalation of asbestos fibers leads to increased risk of developing several diseases such as lung cancer, mesothelioma, asbestosis. In these days, people most at risk for exposure are maintenance and construction workers and general citizens who are working on and close to the work area at which asbestos containing material is disturbing. Non asbestiform, though its chemical composition is same with regulated asbestos, is known to be less hazardous than asbestiform. Exposure guideline, 0.01 f/ml, is not safe level in terms of health risk. It is reasonable to take preventable action when asbestos is suspicious. In Korea, it is necessary to clarify the concept between hazard and risk, to differentiate asbestiform from non asbestiform, to make regulations for compensation for asbestos related patients, to manage future exposure for general citizens.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.43-48
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• 2007

For exposure systems, very accurate alignment between the mask and the substrate is indispensable. In this paper, an automatic alignment system using machine vision for exposure systems is described. Machine vision algorithms are described in detail including extraction of an alignment mark's center position and camera calibration. Methods for extracting parameters for alignment are also presented with some compensation techniques to reduce alignment time. Our alignment system was implemented with a vision system and motion control stages. The performance of the alignment system has been extensively tested with satisfactory results. The performance evaluation shows alignment accuracy of lum within total alignment time of about $2{\sim}3$ seconds including stage moving time.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.301-311
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• 2015

Objectives: Operators of overhead traveling crane in a ship assembly factory perform work to transmit large vessel blocks to an appropriate working process. Hazardous matters such as metal dusts, carbon monoxide, carbon dioxide, ozone, loud noise and fine particles are generated by variable working activities in the factory. The operators could be exposed to the hazardous matters during the work. In particular, welding fumes comprised of ultra fine particles and heavy metals is extremely hazardous for humans when exposing a pulmonary through respiratory pathway. Occupational lung diseases related to welding fumes are increasingly on an upward tendency. Therefore, the objective of this study is to assess properly unknown occupational exposure to the welding fumes among the operators. Methods: This study intended to clearly determine an equivalence check whether or not chemical constituents and composition of the dusts, which existed in the driver's cab, matched up with generally known welding fumes. Furthermore, computational fluid dynamics program(CFD) was used to identify a ventilation assessment in respect of a contamination distribution of welding fumes in the air. The operators were investigated to assess personal exposure levels of welding fumes and respirable particulate. Results: The dust in an operation room were the same constituents and composition as welding fumes. Welding fumes, which caused by the welding in a floor of the factory, arose with an ascending air current up to a roof and then stayed for a long time. They were considered to be exposed to the welding fumes in the operation room. The personal exposure levels of welding fumes and respirable particulate were 0.159(n=8, range=0.073-0.410) $mg/m^3$ and 0.138(n=8, range=0.087-0.178) $mg/m^3$, respectively. They were lower than a threshold limit value level($5mg/m^3$) of welding fumes. Conclusions: These findings indicate that an occupational exposure to welding fumes can exist among the operators. Consequently, we need to be keeping the operators under a constant assessment in the operator process of overhead traveling crane.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.157-170
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• 2014

Objectives: Agent Orange TCDD has been related to serious diseases among Korean veterans who were exposed to it. Decades after the end of the war, however, its effects are still being debated. The object of this study was to examine various unmet needs raised among Agent Orange exposed veterans and their families and to find grounds of a new welfare policy for providing alternative legislation. Methods: Literatures concerning Agent Orange, TCDD, the associated diseases, compensation for veterans and Supreme Court sentencing were searched using PubMed, ProQuest, press news and relevant homepages. Results: Agent Orange exposed veterans are eligible for various benefits from the government, including disability compensation for diseases associated with exposure. The Ministry of Patriots and Veterans Affairs has classified certain diseases into two categories, Agent Orange sequela diseases and sequela suspect diseases and has provided differential benefits based on separated laws. Big differences exist in benefits to veterans and their families between the two laws. The absence of definite standards to classify the Agent Orange associated diseases was confirmed by recent Supreme Court sentencing which ruled in favor of US manufacturers. Conclusion: It appears that the evidence for cause and effect of Agent Orange related diseases would never be perfect. The results suggest a need to change welfare principles from presumptive or indefinite disease basis to exposure experiences combined with integrated disability evaluation. We propose to extend eligibility by enacting a new law for Agent Orange exposed Korean veterans.