• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.827-830
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• 2013

Due to strong wind of smartphone, change in human life is facing 21 Century's new revolution. The end of 2012, The record rate of supply of smartphone is up to 58.8 percent. So the reputation of IT power are continuing. Korea is boasting IT infrastructure, and the reputation of IT power with rapidly evolving. But Korea is one of OECD country with the longest working hours and in labor productivity, yet is located in the lower rank. Now, common social issues such as low-carbon, green growth, low birthrate, graying, labor productivity growth, the reduce greenhouse gas is constantly increasing in worldwide. So Smart Work is getting attention as a way to resolve this. In this paper, we study the impact of small business on local economy and the status information of small business on statistical point of view. And we offer the smart work countermeasures of small business through detailed action elements and the model proposed fot driving factor for the promotion of smart work. Through this, we propose the IT system model for The SMEs-type smart work system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.582-585
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• 2018

As traffic volume increases and road networks become more complicated, identifying for accurate traffic flow and driving smooth traffic flow are a concern of many countries. There are various analytical techniques and studies which desire to study about effective traffic flow. However, the necessary activity is finding the traffic flow pattern through data visualization including location information. In this paper aim to study a real-world urban traffic trajectory and visualize a pattern of traffic flow with a simulation tool. Our experiment is installing the sensor module in 40 taxis and our dataset is generated along 24 hours and unscheduled routes. After pre-processing data, we improved an open source traffic visualize tools to suitable for our experiment. Then we simulate our vehicle trajectory data with a dots animation over a period of time, which allows clearly view a traffic flow simulation and a understand the direction of movement of the vehicle or route pattern. In addition we further propose some novel timelines to show spatial-temporal features to improve an urban environment due to the traffic flow.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.101-104
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• 1998

We report some methods for measuring a LiNbO$_3$ optical phase modulator bandwidth. Since Mach-Zehnder waveguide type, one of methods for modulation bandwidth measurement, is comparatively simple and useful, it was adapted in this work. In order to confirm this method, the waveguide of single and Mach-Zehnder type were fabricated on the same wafer. The Mach-Zehnder interferometric waveguide and the single channel waveguide were used for the measurement of the phase modulator's driving voltage and bandwidth for device fabrications, respectively. Ti-860$\AA$ in-diffusion was achieved in a wet-bubbling oxygen environment at 105$0^{\circ}C$/8hours. LINbO$_3$ internal chips were pigtailed to PMF(polarization maintaining fiber)/SMF(single mode fiber) using an epoxy curing technique. Examined were optical properties such as an insertion loss, propagation loss and mode size, and the loss mechanism of optical coupling between an optical fiber and a waveguide was considered.

• Korean Journal of Materials Research
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• v.18 no.3
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• pp.153-158
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• 2008

Fe-aluminides have the potential to replace many types of stainless steels that are currently used in structural applications. Once commercialized, it is expected that they will be twice as strong as stainless steels with higher corrosion resistance at high temperatures, while their average production cost will be approximately 10% of that of stainless steels. Self-propagating, high-temperature Synthesis (SHS) has been used to produce intermetallic and ceramic compounds from reactions between elemental constituents. The driving force for the SHS is the high thermodynamic stability during the formation of the intermetallic compound. Therefore, the advantages of the SHS method include a higher purity of the products, low energy requirements and the relative simplicity of the process. In this work, a Fe-aluminide intermetallic compound was formed from high-purity elemental Fe and Al foils via a SHS reaction in a hot press. The formation of iron aluminides at the interface between the Fe and Al foil was observed to be controlled by the temperature, pressure and heating rate. Particularly, the heating rate plays the most important role in the formation of the intermetallic compound during the SHS reaction. According to a DSC analysis, a SHS reaction appeared at two different temperatures below and above the metaling point of Al. It was also observed that the SHS reaction temperatures increased as the heating rate increased. A fully dense, well-bonded intermetallic composite sheet with a thickness of $700\;{\mu}m$ was formed by a heat treatment at $665^{\circ}C$ for 15 hours after a SHS reaction of alternatively layered 10 Fe and 9 Al foils. The phases and microstructures of the intermetallic composite sheets were confirmed by EPMA and XRD analyses.

• Human Ecology Research
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• v.51 no.3
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• pp.355-370
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• 2013

The purpose of this study is to investigate the nature of work-family compatibility in the everyday experiences of dual-earner families. By comprehensively describing how dual-earner families manage daily life, this study shows their current situations. In particular, this study overcomes the limitations of previous studies using the phenomenological research methods. Previous studies partially dealt with the problems of dual-earner couples, such as the role conflict of wives and husbands. However, this study broadly demonstrates how wives and husbands as independent individuals manage their lives by working together for a living. Participants were 6 males and 6 females, who lived in Gwangju metropolitan city. Data were collected through in-depth interviews and analyzed using the method of Stevick-Colaizzi-Keen in Moustakas (1994). The results of this study display that dual-earner couples work for a living, but work is the driving force in their life. Family provides dual-earner couples with a stable life, but their stable life is possible by social support like the assistance of a mother-in-law. Dual-earner couples consider work and family as the essential axis of life, thus they give the same value on work and family. Even though dual-earner couples have a difficult time educating their children because of long working hours and coming home late, they positively combine work and family meeting the needs of self-improvement. Therefore, it is necessary to create a working environment that provides enough time for housework and childcare.

• Journal of The Korean Astronomical Society
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• v.51 no.6
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• pp.207-214
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• 2018

A coelostat is often used for solar observations, because it corrects the image rotation automatically by guiding sunlight into a fixed telescope with two plane mirrors. For the purposes of education and spectroscopic observation, the solar group at Seoul National University (SNU) plans to develop the SNU coelostat (SNUC) and install it in the SNU Astronomical Observatory (SAO). Requirements of the SNUC are < 1" positioning accuracy with 30 cm beam size on the entrance pupil in the compact dome. To allow for installation in the small dome, we design a compact slope type coelostat with a 45 cm primary plane mirror and a 39 cm secondary plane mirror. The motion of the SNUC is minimized by fixing the position of the slope frame. Numerical simulations of the available observational time of the designed coelostat shows that the sun can be observed ay all times from June to early August and at least three hours in other months. Since the high accuracy driving motors installed in the SNUC can be affected by external environment factors such as humidity and temperature variations, we design a prototype to test the significance of these effects. The prototype consists of a 20 cm primary plane mirror, a 1 m slope rail, a direct drive motor, a ballscrew, a linear motion guide, an AC servo motor, a reduction gear and a linear encoder. We plan to control and test the accuracy of the prototype with varying atmospheric conditions in early 2019. After testing the prototype, the SNUC will be manufactured and installed in SAO by 2020.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.443-449
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• 2022

In this study, in order to improve the disadvantages of the environmental error of the infusion set that performs infusion therapy in the existing clinical practice and to maximize the user's convenience by miniaturizing the existing infusion pump system, the structure of the muscle pump of the human vein was imitated. As a double check valve method, a method for preventing the backflow of fluid and discharging a constant fluid in one direction by external pressure was proposed. The proposed bio-mimic muscle pump uses a check valve that controls the flow of fluid in one direction and a silicone tube with elasticity, and a chamber is constructed. A peristaltic pump for applying intermittent pressure to the tube chamber was constructed using a multi-cam structure roller. In order to verify the performance of the proposed pump, optimization was performed while changing the number of multi-cam rollers and adjusting the speed of the roller driving motor, and the reproducibility of the instantaneous discharge amount and the continuous discharge amount of the pump was compared and tested. The performance of the muscle pump proposed in this study was verified through experiments that it can inject up to 1L of fluid within 12 hours, and that it is possible to inject the fluid with an accuracy of ±0.1ml. Real-time monitoring of the fluid injection volume through the bio-mimic muscle pump proposed in this study not only increases the convenience of the administrator, but also provides a precise fluid administration environment to more patients at a low cost, and additionally applies bubble detection and occlusion detection technology If so, it is believed that a safer medical environment can be provided to patients.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.506-513
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• 2021

The use of fossil fuels is a major contributor to the increase atmospheric greenhouse gas emissions. As such problems arise, interest in new and renewable energy devices, particularly fuel cells, is greatly increasing. In this study, various characteristics of mixed strains were observed in wastewater collected by the Jeonju Environment Office to investigate the effects of microorganisms on voltage generation and voltage generation of substrates, electrode materials, electrons, electron transport media, and ash microbial fuel cells. As a result of separately measuring the voltage generated during inoculation, the inoculation voltage of Escherichia coli K12 (E. coli K12) was 0.45 V, and the maximum inoculation voltage of the mixed strain was 1.2 V. Thereafter, voltage values were collected using a digital multimeter and the amount of voltage generated over time was measured. In the case of E. coli K12, the maximum voltage reached 0.45 V, and the cell voltage was maintained above 0.23 V for 140 hours. In contrast, for the mixed strain, the maximum voltage reached 1.2 V and the voltage was slowly decreased to 0.97 V. In addition, the degree of microbial adsorption to the electrod surface after the inoculation test was confirmed using a scanning electron microscope. Therefore, these results showed the possibility of purifying pollutants at the same time as power generation through the production of hydrogen ions using microorganisms and wastewater.

• Journal of the Korean Society of Safety
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• v.38 no.4
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• pp.32-38
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• 2023

Job stress factors are factors that induce biological, psychological, and behavioral responses in individuals when they encounter mental and physical stimuli in the workplace. According to occupational safety and health standards, employers are responsible for the health consequences of job stress when workers engage in activities that result in high levels of physical fatigue and mental stress. Such activities include long working hours, shift work (including night shifts), driving vehicles, and operating precision machinery. Therefore, precautionary measures should be implemented. Following the COVID-19 epidemic, the logistics industry in Korea has experienced rapid growth owing to the shift from offline to online platforms facilitated by advanced digital infrastructure. Consequently, this study conducted a survey to analyze job stress factors among delivery workers. The survey utilized a Korean job stress factor assessment tool comprising 43 items and analyzed job stress factors considering the work characteristics of the courier business field obtained from responses provided by 421 courier workers nationwide. The survey analysis revealed that the physical environment, job demands, and job autonomy exhibited higher stress indices among Korean workers. Furthermore, the younger the age, the higher the stress on job demands, whereas the higher the age, the higher the stress on relationship conflict, job instability, and workplace culture. In addition, daytime delivery work was associated with higher stress levels in job demands and job instability compared with nighttime delivery work. These findings can serve as foundational data for reducing and preventing job stress among courier workers, whose workload has increased owing to the growth of the logistics industry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.219-227
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• 2022

In Korea, as the aging phenomenon accelerates, the problem of traffic accidents related to the elderly is continuously emerging. Efforts to improve this are being implemented, but unfortunately the results of these effects are not clear. Therefore, in this study, the effect of traffic characteristics and incentive policies on the return of driver's licenses of elderly drivers was reviewed. As a result of the analysis, it was confirmed that the intention to return the driver's license was low in the case of men, older people, those with low dependence on public transportation, those who undertook long driving hours, and those who took frequent trips. On the other hand, financial incentives were found to play a positive role with regard to the intention to return the driver's license. However, the effect is expected to be insignificant for those with a low intention to return the driver's license. As a result, under the current policy, it is predicted that there is a limit to improving the social problems caused by elderly drivers, meaning that it is necessary to review approaches that induce the return of their driver's licenses.