• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.41-51
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• 2010

This paper describes the development of various lighting equipment adapting Ultra Constant Discharge Lamp that has newly been on commercial supply in the market. Meeting the required conditions of lighting equipment, various types of UCD Lamp equipment with excellent performances could be successfully developed. In order to provide a guideline for the economical lighting product selection, the analyzed data comparison between Hi-pressure Sodium Lamp which has been the most popular lamp for street lighting and UCD Lamp is provided. The conclusions of the study are made as follows; (1) The performance measurement result of UCD Lamp shows excellent Luminous Efficacy as 108Lm/W, daylight-like Color Rendering Index as 90Ra, and the best operating temperature range as $-50^{\circ}C{\sim}+85^{\circ}C$. Comparing to the Hi-pressure Sodium Lamp, UCD could be evaluated as much superior products. (2) In an assembled status with the lighting fixture (Type STB형-60W), UCD Lamp was tested OK for one hour duration at the temperature range form $-50^{\circ}C$ to $+85^{\circ}C$ and the humidity of 98%. The operation at the extremely low temperature can be an excellent feature to enable the export to the cold temperature regions such as Northern Europe and Russia and the specific applications for defense systems and special industry. (3) As UCD Lamp is a genuine Korea made product following Energy-saving and Eco-friendly policy, it should be appreciated as one of the best $CO^2$ reduction Green product.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.347-353
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• 2001

Objectives : To determine the impacts of Diagnosis-Related Groups/Prospective Payment System (DRG/PPS) on the quality of care in cases of Cesarean section and to describe the policy implications for the early stabilization of DRG/PPS in Korea. Methods : Data was collected from the medical records of 380 patients who had undergone Cesarean sections in 40 hospitals participating in the DRG/PPS Demonstration Program since 1999. Cesarean sections were peformed in 122 patients of the FFS(Fee-For-Service) group and 258 patients of the DRG/PPS group. Measurements of quality used included essential tests of pre- and post-operation, and the PPI(Physician Performance Index) score. The PPI was developed by two obstetricians. Results : Univariate analysis demonstrated significant differences in PPI scores according to the payment systems. With respect to the mean of PPI scores, a higher score was found in the DRG/PPS group than in the FFS group. However, the adjusted effect did not show significant differences between the FFS group and the DRG/PPS group. Conclusion : This study suggested that the problem of poor quality may not be related to the implementation of DRG/PPS in Cesarean section. However, this study did not consider the validity and reliability of the process measurement, and it did not exclude the possibility of data emission in medical records.

• PNF and Movement
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• v.16 no.3
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• pp.405-414
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• 2018

Purpose: The purpose of this study was to examine test-retest reliability and criterion-related validity of a trunk stability robot when measuring the weight-bearing symmetry static sitting and standing in stroke patients. Methods: For 27 stroke patients, weight-bearing symmetry was assessed twice, 7 days apart. The intraclass correlation coefficient (ICC2,1) and minimal detectable change (MDC) were used to examine the level of agreement between test and retest. The criterion-related validity of weight -bearing symmetry was demonstrated by Spearman correlation of modified Barthel index (MBI), the sit to stand test (STS), the timed up & go Test (TUG), and the function in sitting test (FIST). Results: the test-retest agreements were excellent for the weight-bearing symmetry of static sitting (ICC2,1: 0.90) and standing (ICC2,1: 0.89). It all showed that the acceptable MDC for the weight-bearing symmetry of static sitting and standing was 0.11 and 0.16, respectively (highest possible score<20 %), indicating that the measures had a small and acceptable degree of measurement error. The weight-bearing symmetry of static sitting was significantly correlated with the TUG(r=-0.45) and FIST(r=0.46)(p<0.05); the weight-bearing symmetry of static standing was also significantly correlated with MBI (r=0.65), TUG (r=-0.67), FIST (r=0.61)(p<0.01), and STS (r=-0.47)(p<0.05). Conclusion: The weight-bearing symmetry of static sitting and standing assessed by the trunk stability robot showed highly sufficient test-retest agreement and mild-to-moderate validity. It could also be useful for clinicians and researchers to evaluate balance performance and monitor functional change in stroke patients.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.125-135
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• 2019

PURPOSE: This study examined the effects of low frequency neuromuscular electrical stimulation (NMES) training on abdominal obesity in middle-aged women through electromyography and ultrasound. METHODS: Twenty-two middle aged women with abdominal obesity participated in the study. A low-frequency NMES device was used on the abdomen and waist of each subject for 20 minutes each (a total of 40 minutes) three times a week for eight weeks. The waist-hip ratio (WHR), weight and BMI (Body Mass Index) were measured. Electromyography (EMG) and ultrasound measurements were performed three times in total (pre-intervention, four weeks into the intervention, and eight weeks post-intervention) to examine the effects of low-frequency NMES on the abdominal muscle activity, muscle thickness, and subcutaneous fat. RESULTS: The results indicated a difference in the WHR and waist circumference before and after intervention (p<.05). The external oblique muscle (EO) showed a significant increase in muscle activity during all measurements taken post-intervention (p<.05). The abdominal subcutaneous fat thickness also showed a significant decrease between each measurement (p<.05). The test results showed that the abdominal subcutaneous fat thickness values taken eight weeks post-intervention were significantly lower than those taken pre-intervention and four weeks into the intervention (p<.05). CONCLUSION: These findings show that low-frequency NMES device training can be applied to middle-aged women with abdominal obesity to improve their body shape and exercise performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.562-570
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• 2019

This study examined the factors affecting the underweight of Korean adolescents using data from Korea youth risk behavior web-based survey, which are national health statistics. This is a second data analysis study using the 13th Korea youth risk behavior web-based survey. The subjects were 48,242 adolescents who range from the first-year middle school students to the third-year high school students. The measurement variables were classified into demographic, physical activity, dietary, and mental health characteristics. The collected data were analyzed by logistic regression analysis. The factors affecting the underweight of Korean adolescents were sex, school type, academic performance, economic level, physical activities, weight control efforts, ramen intake, confectionary intake, stress, and subjective sleep fulfillment rate. Based on the results of this study, we need to search for the measures to help underweight adolescents recover their proper weight.

• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.250-254
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• 2021

A highly sensitive and selective non-dispersive infrared (NDIR) carbon dioxide gas sensor requires achieving high transmittance and narrow full width at half maximum (FWHM), which depends on the interface of the optical filter for precise measurement of carbon dioxide concentration. This paper presents the design, simulation, and fabrication of a Fabry-Perot filter based on a distributed Bragg reflector (DBR) for a low-cost NDIR carbon dioxide sensor. The Fabry-Perot filter consists of upper and lower DBR pairs, which comprise multilayered stacks of alternating high- and low-index thin films, and a cavity layer for the resonance of incident light. As the number of DBR pairs inside the reflector increases, the FWHM of the transmitted light becomes narrower, but the transmittance of light decreases substantially. Therefore, it is essential to analyze the relationship between the FWHM and transmittance according to the number of DBR pairs. The DBR is made of silicon and silicon dioxide by RF magnetron sputtering on a glass wafer. After the optimal conditions based on simulation results were realized, the DBR exhibited a light transmittance of 38.5% at 4.26 ㎛ and an FWHM of 158 nm. The improved results substantiate the advantages of the low-cost and minimized process compared to expensive commercial filters.

• Journal of Distribution Science
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• v.16 no.1
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• pp.87-99
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• 2018

Purpose - The Export Infrastructure Strengthening Program(EISP) is a project to expand exports of agri-food products through providing customized export information to food distribution companies and supporting overseas information activities. A total of 39.6 billion won was provided by 2016. So, the purpose of this study is to analyze whether EISP is effective for expanding exports of agri-food products. Research design, data, and methodology - A simple average difference between the export performance of the policy beneficiaries and the non-policy beneficiaries can be biased if the export capacity or inherent characteristics of the enterprise are not taken into consideration. In order to solve the problem of such a bias, the propensity score matching(PSM) method has been employed in this study. PSM is a method of converting the characteristics of an export company into an index through logit analysis and then reducing the matching to one dimension to improve the accuracy of the performance measurement. Results - The balancing test was conducted to determine how the characteristics of the policy beneficiary group and the matched policy non-beneficiary group corresponded to each other. As a result of the test, we could not reject the null hypothesis that there was no difference between the two groups, so that after the matching, the two groups were similar and the explanatory variables were well controlled. Using the nearest neighbor matching with propensity score estimating through logit analysis, we estimated average treatment effect on the treated(ATT). The food companies participating the EISP had the effect of increasing the exports of $ 5.88 million. As a result, the number of export contracts increased by 11.77, the number of exporting countries by 7.52, the number of export items by 47.51, and the number of buyers' consultation by 3.50. And overseas marketing expenses increased by 35.92 million won. Except for the number of export contracts, other export performance results showed statistically significant results. Conclusions - As the EISP has a positive effect on the expansion of agro-food exports, efforts should be made to find out the limitations or problems of the policy in the future and to make a greater contribution to the increase of exports.

• International Journal of Highway Engineering
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• v.3 no.2 s.8
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• pp.131-140
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• 2001

Concrete pavement of Jungbu Expressway composed of CRCP(Continuously Reinforced Concrete Pavement) and JCP(Jointed Concrete Pavement). The CRCP was firstly constructed and applied to new expressway in Korea. It is a good source of the study to analyze the performance of CRCP and JCP because it experiences same amount of traffic and environmental loading. Up to the present, condition survey has conducted several times during 13 years but roughness measurement has not been carefully conducted. Through comparisons among several types of pavement(CRCP, JCP, Asphalt) by roughness, CRCP is superior to JCP. In addition, connected sections in the highway such as bridges and tunnels that have higher IRI values, about 5mm/m, than normal sections should be considered appropriated maintenance such as diamond grinding. The relationship between IRI and distresses carried out by Korea Highway Cooperation in 1999 skewed that the number of crack is related to IRI value in JCP, while other distresses of JCP and CRCP are not shown clearly. The comparison study with IRI values between Jungbu Expressway and GPS-3(JCP) and GPS-5(CRCP) of LTPP data also showed that roughness of Jungbu Expressway is not inferior to that of the state. Some of section showed larger values of IRI are linked with under-9round structures for passages and drainages. The overall performance considering only roughness, the CRCP is also superior to JCP in sections with under-ground tunnels.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.292-298
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• 2016

In this research, considering the practical situation of separated placing method for mass concrete structure, an efficient method of controlling the heat of hydration is suggested by comparing between the simulated values and actual measurements conducted with the optimum mix design obtained from the various mix conditions with different types and amount of supplementary cementitious materials(SCMs). As the result of the research, firstly, the optimum mix designs for top and bottom layers were determined by Midas gen as OPC to FA of 85 to 15, and OPC to FA to BS of 50 to 20 to 30, respectively. The concrete mixtures prepared with the mix designs determined from the simulation satisfied the target performance range in slump, air content and compressive strength. Additionally, from temperature measurement for the actual mass concrete placed during spring, the maximum temperature difference between surface and core was about $10^{\circ}C$ with 59 and $49^{\circ}C$ for top and bottom layers, respectively, and 1.4 of cracking index was obtained. Therefore, considering the practical conditions of mass concrete construction, it is considered that the different heat of hydration method using different mix designs with SCMs can be an efficient method for controlling thermal cracking and settling cracking of mass concrete.

• Membrane Journal
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• v.20 no.2
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• pp.97-105
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• 2010

This study was to evaluate the performance of the Double stage Pore controllable fiber (DP) filter system as the pre-treatment of the RO membrane. The evaluation for the pre-treatment filter was performed through the indirect method, SDI (Silt Density Index) measurement of the filtrate. This study was done during Jan. 3 of 2009 to Dec. 3 of 2009 at OO Water Treatment Plant that was suppling industrial water to plants, and the raw water was contaminated lake water and it was fed to the system after clarification with coagulation. The average turbidity of the feed water and that of the filtrate was 0.79 NTU (0.28~4.01 NTU), and 0.16 NTU (0.04~0.50) respectively. And so the average turbidity removal efficiency was 77%. The filtrate flow rate and the backwash water flow rate was about 230 $m^3$/day and about 8.7 $m^3$/day respectively, and so the backwash rate was 3.8%. The data for some samples were obtained after a few days storage, and it caused the higher turbidity and SDI15 as the storage time was increased. But average SDI value of the filtrate was 3.6 (2.26~5.00) which was lower than minimum value required by the RO membrane manufacturer as the RO feed water to guarantee the life time of the RO membrane. So, the DP filter system was enough for the application as the pre-treatment of the RO membrane.