• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.349-355
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• 2015

Background: The tuberculin skin test (TST) is the standard tool to diagnose latent tuberculosis infection (LTBI) in mass screening. The aim of this study is to find an optimal cut-off point of the TST+ rate within tuberculosis (TB) contacts to predict the active TB development among adolescents in school TB outbreaks. Methods: The Korean National Health Insurance Review and Assessment database was used to identify active TB development in relation to the initial TST (cut-off, 10 mm). The 7,475 contacts in 89 schools were divided into two groups: Incident TB group (43 schools) and no incident TB group (46 schools). LTBI treatment was initiated in 607 of the 1,761 TST+ contacts. The association with active TB progression was examined at different cut-off points of the TST+ rate. Results: The mean duration of follow-up was $3.9{\pm}0.9years$. Thirty-three contacts developed active TB during the 4,504 person-years among the TST+ contacts without LTBI treatment (n=1,154). The average TST+ rate for the incident TB group (n=43) and no incident TB group (n=46) were 31.0% and 15.5%, respectively. The TST+ rate per group was related with TB progression (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.001-1.050; p=0.037). Based on the TST+ rate per group, active TB was best predicted at TST+ ${\geq}$ 16% (OR, 3.11; 95% CI, 1.29-7.51; area under curve, 0.64). Conclusion: Sixteen percent of the TST+ rate per group within the same grade students can be suggested as an optimal cut-off to predict active TB development in middle and high schools TB outbreaks.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.130-135
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• 2010

In this paper, the shading ratio about to output the minimum critical power of a photovoltaic panel was determined by experiment and simulation. A 2.475[kW] poly-crystalline photovoltaic panel consisting of 11 modules was used in the experiment and its surface was covered with shading curtains, thus the amount of light incident to the modules were controlled. In order to compare with the experimental results, the experimental circuits were modelled with the CASPOC (power electronics electrical drives simulator) and module parameters were applied to it, by which the minimum critical power was calculated. As a result, the photovoltaic panel was about to generate the power when the 5th shading curtains were removed from the module surface, after then the output power linearly increased by removing the shading curtains. In addition, the CASPOC simulation results were similar to the experimental results in the abrupt decreasing pattern of power.

• Journal of Agricultural Extension & Community Development
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• v.22 no.2
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• pp.117-133
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• 2015

This study explored at marital conflict in multicultural families, a type of families formed through international marriages, from husbands perspectives. For the purpose of this study, in-depth interviews were used with husbands in multicultural families to ask about marital conflict, and then, conducted a qualitative case analysis. In summary, results of this study are as follows; First, among the decisive events that husbands in multicultural families often experienced in marital conflict with their wives were disrespect toward husbands and parents-in-law, husbands with a low level of trust, feelings of pressure due to financial support for wives' families and children and lack of practical sense about marriage. Second, development of marital conflict that husbands often experienced included aggravated cultural conflict between a couple and between members of the family, difficulty in managing blame and anger, signs of separation or divorce and wives leaving home and limitations in conversation and communication. Third, as to how husbands tried to deal with marital conflict, they tried to be patient and comfort wives, engage in economic activities together, find something that they could focus on, turn to religion or gatherings, use service from government organizations, have trust and develop rules and limit the range of their wives activities.

• Korean Journal of Optics and Photonics
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• v.32 no.4
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• pp.172-179
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• 2021

A near-normal-incidence ellipsometer (NNIE) is suggested as an optical critical dimension (OCD) measurement system that is highly sensitive to the bottom defect of a sample with high-aspect-ratio structured patterns. Incident light passes through a polarizer and a phase retarder in sequence, and the reflected light from the sample also passes through them, but in reverse order. The operating principle of this NNIE, where a single polarizer and a single phase retarder are shared by the incident and reflected light, is studied, and a method to determine the ellipsometric constants from the measured intensities at proper combinations of the azimuthal angles of polarizer and retarder is presented.

• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.58-67
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• 2021

Incident investigation is regarded as a means to improve safety performance. For the prevention of industrial accidents, measures such as providing safety education, enhancing management interest and participation, establishing a safety management system, and conducting inspection of the work site are necessary. In particular, accident investigation activities, which are an important element of safety management, help to prevent similar accidents, thereby minimizing damage and enhancing work safety. They are critical for understanding business-related incidents and the vulnerabilities and opportunities associated with them. Therefore, it is clear that accident investigation activities are important for accident prevention. The primary focus of many incident investigation processes is on identifying the cause of an event. While considerable research has been conducted on potential accident investigation tools there has been little research on including the views and experiences of practitioners in the accident investigation process. In this study, a questionnaire survey was conducted among safety managers in the domestic manufacturing/construction industry to understand the practice of accident investigation. The investigation pertained to companies' accident investigation systems, the competence of investigators, and the identification and recommendations of the cause of accidents. From the analysis results of accident investigations, investigators' competence, the difficulty level of investigations, and the root causes of accidents were identified from the viewpoint of the participants of the accident investigations. In particular, the development of standardized and simple accident investigation methods and their dissemination to companies were found to be necessary for activating the root cause of accidents. Based on this, it can be used as basic data for the development of root cause analysis investigation techniques that are easily applicable to organizations.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.4
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• pp.199-203
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• 2006

This paper presents an ASER (Accelerated Soft Error Rate) integral model. The model is based on the facts that the generated EHP/s(electron hole pairs) are diminished after some residual range of the incident alpha particle, where residual range is a function of the incident angle and the capping layer thickness over the semiconductor junction. The ASER is influenced by the flux of the alpha particles, the junction area ratio, the alpha particle incident angle when the critical charge is same as the collected charge, and the sizes of the alpha source and the chip. The model was examined with 8M static RAM samples. The measured ASER data showed good agreement with the calculated values using the model. The ASER decreased exponentially with respect to the operational voltage. As the capping layer thickness increases up to $16{\mu}m$, the ASER increases, and after that thickness, the ASER decreases. The ASER increased as the depth of BNW increased from $0{\mu}m\;to\;4{\mu}m$. and then saturated. The ASER decreased as the node capacitance increased from 2fF to 5fF.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.200-206
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• 1996

When a Gaussian beam is incident to a planar dielectric interface at an angle other than Brewster angle or the critical angle of total reflection, we derive the six nonspecular effects of rotation, lateral shift, focal shift, Rayleigh length change, magnitude and phase changes in the complex amplitude of the reflected beam simultaneously by taking account of the boundary condition. In the derivation we assume a Gaussian beam of fundamental mode to emerge from the interface and then match at the interface the constant, linear, and quadratic variations of the amplitude and phase of the reflected beam with those of the incident beam multiplied by the reflection coefficient. Our calculation shows that the six nonspecular effects can result from a linear variation of the natural logarithm of the reflection coefficient at the interface.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.146-147
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• 2000

The electromagnetic wave scattering from active objects has only recently attracted attention.$^{(1).(3)}$ Theoretical studies have considered normal-incidence plane-wave interactions with active dielectric cylinders with the prediction of large enhancements in the scattered field for bound mode structures. According to the theory of the electromagnetic wave scattering from a dielectric cylinder, the eigenvector solutions are discrete and have both guided (non-radiative) and leaky (radiative) mode solutions. By using an anti-guiding (leaky) structure instead of a guided structure and scattering at oblique incident angles near critical angle, the scattering resonances predicted by theoretical studies were obtained for the first time. A fine-grained scan of the plane-wave incident angle a reveals the existence of discrete scattering resonances. The diameter and real part of the index of refraction determine the resonant conditions and the imaginary part of the refractive index has a threshold value to make mode up for its radiation loss. The cross coupling between transverse electric (TE) and transverse magnetic (TM) modes is clearly detected for both active and passive scattering as theoretically expected. (omitted)

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.391-397
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• 2001

The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angel and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.40.1-40.1
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• 2021

Hydrogen is the most abundant element in the universe, which is, in the cosmological context, attributed to its simplest structure consisting of a proton and an electron. Hydrogen interacts with an electromagnetic wave in astrophysical environments. Rayleigh scattering refers to elastic scattering, where the frequencies of the incident and scattered photons are the same. Rayleigh and resonance scattering is a critical role study Lyman Alpha objects in the early universe. The scattering causes the frequency and spatial diffusion of Lyα. In the case of Raman scattering, the energies of the incident and scattered photons are different. The photons near Lyβ convert to the optical photons near Hα through Raman scattering. The photon scattered by atomic hydrogen can carry both of the properties of the H I region and the emission region. I adopt a Monte Carlo approach to investigate the formation of the various spectral line features through Rayleigh and Raman scattering in highly thick media of atomic hydrogen. In this thesis, I present my works on radiative transfer involving the scattering processes between far UV photon and atomic hydrogen. I introduce scattering processes with atomic hydrogen and the spectral, spatial, and polarized information originating from the scattering.