• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10683-10690
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• 2015

The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web-based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.2
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• pp.153-169
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• 2018

A submarine has a pressure hull that can withstand high hydraulic pressure and therefore, requires the use of highly advanced shipbuilding technology. When producing a pressure hull, periodic inspection, repair, and maintenance are conducted to maintain its soundness. Of the maintenance methods, Non-Destructive Testing (NDT) is the most effective, because it does not damage the target but sustains its original form and function while inspecting internal and external defects. The NDT process to detect defects in the welded parts of the submarine is applied through Magnetic particle Testing (MT) to detect surface defects and Ultrasonic Testing (UT) and Radiography Testing (RT) to detect internal defects. In comparison with RT, UT encounters difficulties in distinguishing the types of defects, can yield different results depending on the skills of the inspector, and stores no inspection record. At the same time, the use of RT gives rise to issues related to worker safety due to radiation exposure. RT is also difficult to apply from the perspectives of the manufacturing of the submarine and economic feasibility. Therefore, in this study, the Phased Array Ultrasonic Testing (PAUT) method was applied to propose an inspection method that can address the above disadvantages by designing a probe to enhance the precision of detection of hull defects and the reliability of calculations of defect size.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1101-1112
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• 2021

Organizations continue to increase investment in information security(IS) policies and technologies to prevent external intrusion and internal exposure to information assets. However, as the organization's regulations and behavioral requirements for strict IS policy increase, employees may induce negative behaviors through IS-related stress. The purpose of this study is to suggest the effects of challenge and hindrance stressors on IS compliance intentions and to confirm how authentic leadership moderates the positive and negative effects of stressors. We reflected employees of the organization who are applying IS policy to their work as a study target and applied a survey to obtain a sample for research hypothesis verification. As a result of analysis through structural equation modeling, challenge and hindrance stressors affected IS compliance intentions, and authentic leadership moderated the effects of stressors on compliance intention. Our research helps to establish insiders support strategies to achieve internal IS goals, because the results suggested stressor conditions and leaders' behavioral directions that influence employees IS compliance behavior.

• Korean Journal of Social Welfare Studies
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• no.36
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• pp.203-225
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• 2008

The purpose of this study is to examine how much the external locus of control, social support, self-esteem, and adoption decision making process influence to teen parents' grief and find out the differences depending on meeting the baby, breast-feeding, anticipating the meeting the baby, ceremony for separation, and exposing their grief by themself or to others. Data was analysed with multiple regression and t-test. With the result of multiple regression analysis, the higher external locus of control, pressure of birthfather, regrets for adoption decision are, the higher grief is, and the lower support of friends and self-esteem are, the higher grief is. And It is estimated high grief statically among the group of breast-feeding, anticipating the baby, no ceremony for separation. But the group exposing their grief by self or to others felt low grief. On the basis of the results, we will find out the meaningful contents for intervention. The staffs of birthmother shelter and social worker don't overlooking the relationship between birthmother and birthfather and enforce the internal locus of control, self-esteem. Above all we will intervene about exploring the adoption decision making and facilitate the exposure of feeling related to surrendered baby(guilt, anxiety, sadness, shame, fear).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.15-15
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• 1999

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the conventional rotating barrel. vibrational barrel (vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components, The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed that the average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value, Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components, However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. $2HD{\;}+{\;}e{\;}{\rightarrow}20H{\;}+{\;}H_2$ Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure thereby resulting to bad plating condition. 1 lot of chip was divided into two equal partion. Each portion was loaded to the same barrel one after the other. Nickel plating and tin-lead plating was performed in the same station. Portion A maintained the normal barrel vibration intensity and portion B vibration intensity was increased two steps higher. All other parameters, current, solution condition were maintained constant. Generally, plating method find procedures were carried out in a best way to maintained the best plating condition. After plating, samples were taken out from each portion. molded and polished. Plating thickness was investigated for both. To check consistency of results. 2nd trial was done now using different lot of another characteristics.

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1342-1346
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• 1996

A right thoracotomy was used for the reoperation or mitral valve of 15 patients who had previously undergone a cardiac operation through a median sternotomy. In our experience. this approach provided dn excellent exposure of the nlitral valve and easy cannulations of both cavie with minimal dissection, ilvoiding any damage of cardiac and major vessels during re-sternotomy Arterial cannulation was performed in the ascending aorta in 13 patients And in the femoral artery in 2 patients. In earlier cases, venous cannulation was done in the SVC And IVC through the right atrium and snared. In later cases, this could be done without snaginly of both cavae or by placing a silgle light-angled catheter into the right atrium. Crystalloid cardioplegic solution was infused for myocardial protection. Hypothermia was controlled at 20\ulcorner$25^{\circ}C$. For defibrillation, internal paddles were used In one patient while sterilized external paddles were used in 10 patients. In the remaining four patients. however. the heart beat spontaneously The respirator could be weaned within 48 hours alter the operation and no pulmonary complication was observed. One out of the 15 patients expired due to sudden attack of ventricular tarchycardid developed ten days after the operation, but the rest of the patients were discharged with good condition.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.741-744
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• 2008

Quality control of early age concrete significantly influences the long term performance. Primary factors for early age concrete quality control should include the relative humidity and temperature variation, and these are more important as structures become massive and huge. Temperature raise due to cement hydration causes stress, which can develop to cracking with internal and/or external restraints. Exposure conditions including ambient temperature, humidity and wind also significantly affect the cracking behavior of early age concrete. Among many of studies on the early age concrete behavior, investigation on the variation of temperature and relative humidity internal of concrete is not common. That is in part because the difficulties in measuring the relative humidity and temperature inside the concrete. This study used a digital sensor with an appropriate logger to measure internal temperature and relative humidity. This direct measuring method is expected to provide more reliable and comprehensive data acquisition on the early age behavior of concrete.

• The Korean Journal of Applied Statistics
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• v.6 no.2
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• pp.201-215
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• 1993

The health status of workers in a foundry was analyzed in a study which consisted of evaluations of respiratory health together with environmental measurements. The results from environmental measurements showed values exceeding permissible exposure limits. A t-test was done with log transformed and untransformed data to examine the statistical significance for the noncompliance with exposure standards. For the analysis of categorical health outcomes, $\chi$-square test with 2 $\times$ 2 tables and logistic regression analysis were employed. For continuous variables, multiple linear regression was done against assessed risk factors. Pros and cons of different parameters in the compliance (or noncompliance) testing were presented. Respiratory function did not show any relation with occupational exposures, which may be due to the healthy worker effects. Strategies for controlling time dependent covariates were discussed in relation to the healthy worker effect. The scope of statistical analysis in occupational health studies is still limited in Korea without a suitable external comparison group such as credible vital statistics for the whole nation. Internal comparisons between different exposure status often result in unstable estimates of effect, and proportional morbidity study is discussed as an alternative potential research tool.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.111-122
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• 2021

Objectives: There was a judgment of acquittal for the manufacturer SK Chemical and the vendor Aekyung regarding humidifier disinfectant (HD) containing 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT). The rationale used in this judgement is discussed here in the light of scientific consideration. Methods: The sentencing document for the judgements was obtained from the Korea Supreme Court Service. In particular, the judgements made by the court related to the risk of HD and external and internal exposure to CMIT/MIT are discussed based on scientific evidence. Results: Rendering a determination in a criminal trial of insufficient evidence of causation, the court dismissed the prosecution's motion that humidifier disinfectant-associated lung injuries (HDLI) and asthma were associated with the utilization of these products. However, CMIT/MIT, a strong sensitizing and corrosive substance, has been reported to be associated with brain toxicity, allergic contact dermatitis, and asthma. Furthermore, the judgment did not consider total consumption amounts or the cumulative dose of CMIT/MIT in the humidifier. Lastly, there are several cases supporting the fact that exposure to water-soluble substances including CMIT/MIT can cause lower respiratory tract diseases. In addition to cases of asthma among the workers exposed to CMIT/MIT, we identified lung injury victims who were exposed to HDs exclusively containing CMIT/MIT. Conclusions: We conclude that there is sufficient evidence supporting the assertion that HDs containing CMIT/MIT cause lung injuries, including asthma, contrary to the court's judgement.

• The Korean Journal of Physiology
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• v.22 no.1
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• pp.13-29
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• 1988

In order to elucidate the regulatory mechanism of intracellular calcium ion concentrations, contractions or contractures induced by $Na^{+}-removal$, calcium-application or ouabain-treatment as an index of $Na^+/Ca^{2+}$ exchange activity were studied in atrial muscle or vascular smooth muscle (aorta and renal artery) of the rabbit. The magnitude of low sodium contractures in atrial trabeculae increased with sigmoid shape when external sodium concentrations were reduced to sodium-free condition, whereas that of calcium contracture intensified in a parabolic pattern when external calcium concentrations were elevated to 8 mM. $Na^{+}-removal$ contractures were induced in a duration-dependent manner to $K^{+}-free$ exposure and same findings were observed with ouabain treatment. $Na^{+}-free$ contractures were not affected by verapamil treatment, but stimulated by $100{\mu}M\;Mn^{2+}$ and inhibited by high concentrations of $Mn^{2+}\;(2{\sim}8mM)$ in a dose-dependent manner. Ryanodine which is known to suppress the release of calcium from internal store abolished spontaneous twitch contractions induced by $K^{+}-free$ solution, but had no effect on the development $Na^{+}-free$ contractures. Na-free contractures were not always induced in vascular smooth muscle preparations. Contractures by $O\;mM\;Na^+$ were usually seen in aorta, but not often in renal artery.$50\;mM\;K^+$, noradrenaline (NA) and angiotensin II (AII) always evoked very large contraction in all preparations of vascular smooth muscle. Contractures developed by $O\;mM\;Na^+$ were not sensitive to verapamil treatment as in atrial trabeculae, but were abolished by $100{\mu}M\;Mn^{2+}$. In contrast to $Na^{+}-free$ contractures, $Mn^{2+}(100{\mu}M)$ had no effect on the contractures induced by NA or 50 mM$K^+$. Caffeine in the concentration of 10 mM evoked transient contracture in the distal renal artery. The rate of spontaneous relaxation in caffeine contracture was dependent upon the concentrations of external sodium, and had double component of relaxation when the rate of relaxation was plotted in the semilogarithmic scale of relative tension versus time. Especially late components of relaxation had more direct relation to $Na^+$ concentrations. It could be concluded that $Na^+/Ca^{2+}$ exchange mechanism in the heart has a large capacity, inhibited by $Mn^{2+}$ but not by verapamil and ryanodine, while $Na^+/Ca^{2+}$ exchange system in vascular smooth muscle has a very low capacity especially in small artery, inhibited by low concentration of $Mn^{2+}\;(100{\mu}M)$ but not affected by verapamil and ryanodine.