• Journal of Korean Public Health Nursing
• /
• v.31 no.1
• /
• pp.84-96
• /
• 2017

Purpose: Vitamin D is a fundamental element for bone metabolism. Recently vitamin D deficiency has been implicated in various diseases such as a cardiovascular disease, diabetes, and cancers. The aim of this study was to identify the risk factors associated with serum vitamin D deficiency among women office workers. Methods: We selected 369 women office workers using the secondary data of the 5th National Health & Nutrition Examination Survey 2010-2012. Data was analyzed by logistic regression of complex sampling design. Results: Women office workers with vitamin D deficiency, defined serum 25-hydroxyvitamin D concentration < 10ng/mL, were 12.5%. The risk factors for vitamin D deficiency were 20s aged group, married state and more than 40 working hours a week. The risk of vitamin D deficiency was decreased in those with alcohol drinking 1 to 4 times a month. The education level, income, region, smoking, physical activity and sun exposure time did not affect the risk of vitamin D deficiency significantly. Conclusion: Development of vitamin D deficiency prevention educational programs are required for women office workers who more than 40 hours a week in 20s. It should be considered health education including sun exposure duration and behavior.

• KSBB Journal
• /
• v.28 no.6
• /
• pp.339-348
• /
• 2013

Translational research (TR) as high quality research can accelerate collaboration strongly between biotechnology-based researchers and clinical-research experts for overcoming diseases. TR facilitates basic science translated to clinical efficacy and effectiveness from bench (basic science) to bedside (clinical practice) for the enhancement of human health. Disease-oriented TR programs were defined as unilateral, bilateral and multilateral TR in this patent performance analysis. Patent performance was measured in a R&D project on Health and Medical Technology to enhance the productivity of R&D investment on disease-oriented TR in Health Technology (HT). Patent Map (PM) analysis and Bibliometrics were conducted to collect information for the assessment of research patents of TR programs. Futhermore, PIAS (Patent Information Analysis System) and Thinklear programs were applied for quantitative and qualitative analysis successfully. These indicate that multi-dimensional analysis of patent performance for disease-oriented TR could promote the connection of R&D-IP (Research and Development-Intellectural Property) and R&BD (Research and Business Development) supporting system significantly.

• KSBB Journal
• /
• v.27 no.1
• /
• pp.1-8
• /
• 2012

Recently, translational research (TR) in health technology (HT) has been considered as an emerging alternative research system for the improvement of human health. TR from bench to bedside involves a strong bidirectional relationship between basic science discovery and clinical practice. To support R&D planning and policy in HT effectively, the performance of TR programs was analyzed and evaluated in a R&D project on health and medical technology. TR programs were classified into three parts: unilateral TR, bilateral TR and multilateral TR. Bibliometrics and citation analysis were performed to assess research papers and gather information for the performance analysis of TR programs. In addition, both quantitative and qualitative analysis were successfully carried out using ISI Web of Science, Google Scholar Citations, SCOPUS and Knowledgematrix. In conclusion, the performance analysis of TR programs could significantly improve the efficiency of R&D plans, R&D management and evaluation for a safe and healthy life.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.4
• /
• pp.35-41
• /
• 1998

The workplace noise environment is composed of three basic elements : manufacturing (in a generic sense) facilities, office areas, and the community around the facility. Work must be done by all employees , and this involves communication within a variety of locations within the facility ; areas may be extremely noisy, moderately noisy, or quiet, such as an office. At the same time, the facility should not be annoying to the community. In this paper, the workplace environmental noise of office areas in power plant are studied. Turbine generator in power plant generates the noise of 90∼95 dB(A) in the frequency range of 1 kHz, which may cause occupational hearing loss. By abatement method which are made of isolation material and distance damping effect, about 29.5 dB(A) reduction has been obtained in office areas of the Power Plant . But, the workplace environmental noise of office areas in the power plant is not suited to office's purpose.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.4
• /
• pp.54-63
• /
• 2022

A 3-tonf class liquid rocket engine that powers the upper stage of a small launcher and lifts 500 kg payload to 500 km SSO is designed. The small launcher is to utilize the flight-proven technology of the 75-tonf class engine for the first stage. A combination of liquid oxygen and liquid methane has been selected as their cryogenic states can provide an extra boost in specific impulse as well as enable a weight saving via the common dome arrangement. An expander cycle is chosen among others as the low-pressure operation makes it robust and reliable while a specific impulse of over 360 seconds is achievable with the nozzle extension ratio of 120. Key components such as combustion chamber and turbopump are designed for additive manufacturing to a target cost. The engine system provides an evaporated methane for the autogenous pressurization system and the reaction control of the stage. This upper stage propulsion system can be extended to various missions including deep space exploration.

• Journal of Aerospace System Engineering
• /
• v.11 no.6
• /
• pp.76-83
• /
• 2017

The MIL-STD-1553 standard has been used for over 40 years as a data bus technology for high-reliability mobile systems. However, 1 Mbps transmission speed is absolutely insufficient to implement sensor data convergence, which is an essential requirement of modern aerospace systems. In this paper, we analyze the hierarchical structure of the MIL-STD-1553B version specification and describe several methods to increase the transmission speed without losing the advantages of the existing MIL-STD-1553 bus. In addition, we analyzed the R & D cases of the high-speed MIL-STD-1553 technology, which have been conducted in leading aerospace countries.

• Journal of Obesity & Metabolic Syndrome
• /
• v.26 no.1
• /
• pp.52-60
• /
• 2017

Background: This study investigated the relationship between depressive symptoms and physical fitness, obesity indices, and vitamin D status in office workers. Methods: The subjects were 514 adults with more 30 years of experience as office workers in the city of Seoul. Lifestyle risk factors, obesity indices, physical fitness, and serum vitamin D levels were assessed with a standardized protocol. The Beck Depression Inventory (BDI) was used to assess depression status. Vitamin D status was assessed by measuring serum 25-hydroxyvitamin D concentrations. Based on the BDI scores, participants were classified into no depression (ND, $BDI{\leq}9$), mild depression (MiD, $10{\leq}BDI{\leq}15$), and moderate depression (MoD, $16{\leq}BDI{\leq}23$) groups. Results: Compared with the high cardiorespriatory fitness group, the low cardiorespiratory fitness (men OR=2.618, women OR=1.596) an middle cardiorespiratory fitness group (men OR=1.256, women OR=1.110) had significantly higher odds ratio for having depressive symptoms, even after adjustment for age, hypertension, diabetes, hyperlipidemia, cardiovascular disease, alcohol intake, smoking, body mass index (BMI), percent body fat (%BF), and waist circumference (WC). Compared with the insufficient or deficient vitamin D group , the sufficient vitamin D group had significantly lower odds ratios for having depressive symptoms (men OR=0.121, women OR=0.114), even after adjustment for age, hypertension, diabetes, hyperlipidemia, cardiovascular disease, alcohol intake, smoking, BMI, %BF, and WC. Conclusion: Vitamin D supplementation and outdoor activities should be key components of a lifestyle intervention against office workers' depression.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.6
• /
• pp.617-626
• /
• 2023

This study aims to investigate the preferred sound level of water sound for various levels of open-plan-office noise regarding soundscape quality and speech privacy. And assessment of the work efficiency of the water sound. For the laboratory experiment, office noise was recorded using a binaural microphone in a real open-plan office. For the assessment of the soundscape quality and speech privacy, Overall Soundscape Quality (OSQ) and Listening Difficulty (LD) were evaluated under three different sound levels (55 dBA, 60 dBA, and 65 dBA) and five different signal-to-noise ratios (SNR -10 dB, -5 dB, 0 dB, +5 dB, and +10 dB). After the evaluation, the preferred SNR was proposed according to OSQ and LD. For the assessment of to work efficiency of water sound, this study evaluated the cognitive performance of both of the condition noise only and combine the water sound with office noise. The results showed that LD increased as the water sound level increased, but OSQ decreased. When the water sound level was more than the office noise level, the OSQ decreased from noise only. Therefore, considering OSQ and LD, the preferred SNR of water sound was -5 dB for all noise levels. At the preferred level of water sound, the cognitive performance results were shown to decrease at 55 dBA compared to noise only, but at 60 dBA and 65 dBA combine the water sound results were increased than the noise only.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.3
• /
• pp.101-112
• /
• 2021

SpaceX shows various strategies such as constructing various payload portfolio through the reuse of Falcon 9 and Falcon Heavy, constructing the launch vehicles using one type of engine, the transition from kerosene engine to methane engine, and the use of 3D printing. In this study, launch vehicle proposals that can cover a variety of payloads and trajectories from KOMPSAT to GEO-KOMPSAT were constructed, and ten launch vehicles using kerosene gas generator cycle engine, kerosene staged-combustion cycle engine, and methane staged-combustion cycle engine were reviewed. Of the ten launch vehicles, the reusable launch vehicle using a 35-ton methane engine was rated as the best in terms of development potential.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.2
• /
• pp.119-143
• /
• 2021

Selecting liquid methane as fuel is a prevailing trend for recent rocket engine developments around the world, triggered by its affordability, reusability, storability for deep space exploration, and prospect for in-situ resource utilization. Given years of time required for acquiring a new rocket engine, a national-level R&D program to develop a methane engine is highly desirable at the earliest opportunity in order to catch up with this worldwide trend towards reusing launch vehicles for competitiveness and mission flexibility. In light of the monumental cost associated with development, fabrication, and testing of a booster stage engine, it is strategically a prudent choice to start with a low-thrust engine and build up space application cases.