• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.457-457
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• 2022

최근 기후변화로 인한 위기가 인류의 생존을 위협하면서 전 지구적으로 기후변화에 대응하기 위한 탄소 중립 대책을 모색하고 있으며, 지속가능한 신재생에너지에 대해 주목하고 있다. 산업통상자원부는 2034년까지 총 발전량 중 신재생에너지의 비율을 25.8%까지 증가시키는 것을 목표로 신재생에너지의 발전 비율을 증가시키기 위한 다양한 노력을 기울이고 있다. 특히, 신재생에너지 중 가장 많은 비중을 차지하고 있는 태양광 발전은 비교적 광범위한 부지를 필요로 하고 있으며, 환경 및 지형적 영향이 크게 작용하는 만큼 발전 시설 부지 선정 및 운용 계획을 위한 면밀한 분석이 필수적이다. 그러나, 태양광 발전 활용 계획을 수립하기 위해 고려할 수 있는 지상 관측 일사량 및 일조량 데이터는 상당히 제한적이며 관측 밀도가 조밀하지 않다는 한계점이 있다. 본 연구에서는 천리안위성의 후속으로 발사된 천리안2위성의 산출물인 일사량 데이터를 활용하여 한반도 영역에서의 일사량에 대한 시·공간적 분석을 수행하였으며, 이를 기반으로 각 지역적 특성을 파악하고, 토지 피복 유형에 따른 태양광 발전의 효율 정도를 분석·평가하였다. 본 연구의 결과는 계측 지역 및 미계측 지역에서의 시공간적인 태양광 에너지의 효율성에 대한 정보를 제공함에 따라 태양광 발전을 위한 관련 시설물들의 최적 설치 위치 및 규모 등에 대한 설계 기준 마련에 활용될 수 있을 것으로 판단된다.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.125-130
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• 2024

With the rapid growth of mobility technology, the industrial sector is demanding storage devices that can reliably process data from various equipment and sensors in vehicles. NAND flash memory is being utilized as a storage device in mobility environments because it has the advantages of low power and fast data processing speed as well as strong external shock resistance. However, flash memory is characterized by data corruption due to long-term exposure to high temperatures. Therefore, a dedicated system for temperature management is required in mobility environments where high temperature exposure due to weather or external heat sources such as solar radiation is frequent. This paper designs a dedicated temperature management system for managing storage device temperature in a mobility environment. The designed temperature management system is a hybrid of traditional air cooling and water cooling technologies. The cooling method is designed to operate adaptively according to the temperature of the storage device, and it is designed not to operate when the temperature step is low to improve energy efficiency. Finally, experiments were conducted to analyze the temperature difference between each cooling method and different heat dissipation materials, proving that the temperature management policy is effective in maintaining performance.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.53-58
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• 2024

This paper presents a novel miniaturized 3-D cubic antenna for use in wireless sensor network (WSN) application. The geometry of this antenna is designed as a cube including a meander dipole antenna. A truly omnidirectional pattern is produced by this antenna in both E-plane and H-plane, which allows for non-intermittent communication that is orientation independent. The operating frequency lies in the ISM band (centered in 2.45 GHz). The dimensions of this ultra-compact cubic antenna are 1.25*1.12*1cm3 which features a length dimension λ/11. The coefficient which presents the overall antenna structure is Ka=0.44. The cubic shape of the antenna is allowing for smart packaging, as sensor equipment may be easily integrated into the cube hallow interior. The major constraint of WSN is the energy consumption. The power consumption of radio communication unit is relatively high. So it is necessary to design an antenna which improves the energy efficiency. The parameters considered in this work are the resonant frequency, return loss, efficiency, bandwidth, radiation pattern, gain and the electromagnetic field of the proposed antenna. The specificity of this geometry is that its size is relatively small with an excellent gain and efficiency compared to previously structures (reported in the literature). All results of the simulations were performed by CST Microwave Studio simulation software and validated with HFSS. We used Advanced Design System (ADS) to validate the equivalent scheme of our conception. Input here the part of summary.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.768-773
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• 2009

This paper demonstrates the digital communication in air using the parametric array. The stepped-plate transducer which is suitable for high-power and high-efficient radiation is used to generate the difference frequency wave with the parametric array. The primary frequencies are selected to 83 kHz and 122 kHz and the resulting difference frequency wave at the frequency of 39 kHz is used for the communication. The modulation method is selected to On-Off Keying method. The waveform and signal-to-noise ratio (SNR) is measured and analyzed to see the characteristics of the digital communication using the parametric array. The proper distance for the communication using parametric array is about 3 m. The measured beam width of the 3dB SNR reduction was $14^{\circ}$. The possibility of the communication in air using the parametric array is confirmed and the high directional characteristic of the communication using the parametric array is expected to have the advantages for the multi path and the security problems.

• Journal of The Korea Institute of Healthcare Architecture
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• v.30 no.2
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• pp.35-46
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• 2024

Purpose: It is the responsibility of public healthcare to respond quickly to infectious disease outbreaks and disasters such as MERS, COVID-19, the Syrian earthquake, and the Miryang Sejong Hospital fire accident. It is very important to secure safe medical facilities and protect lives through emergency medical support and disaster response systems. The purpose of this study is to investigate the safety status of regional medical facilities that play a central role in the event of a disaster. Methods: The target was 41 local public hospitals, including 35 regional medical centers and 6 Red Cross hospitals nationwide. We delivered a questionnaire to 41 medical facilities and collected data from 32 regional public hospitals that received responses. Results: In order to respond to safety accidents, a survey was conducted on infections, falls, patient identification, and incorrect connections for medical accidents, and for in-hospital accidents, a survey was conducted on entrapment, collision, water leaks, falling objects, and crime prevention. For natural disasters, we investigated the response environment for typhoons, floods, and snow damage, and for social disasters, we investigated the response environment for fire, power outages, and radiation damage. Implications: We hope that it will be used as basic data for developing standards and creating hospital facilities and environments that are safe for everyone to respond to various disasters and prevent patient safety accidents in the future.

• Korean Journal of Food Science and Technology
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• v.5 no.1
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• pp.6-15
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• 1973

In an attempt to develop composite flours based on raw materials available in Korea, six domestic resources were investigated with respect to their physical and chemical properties, nutritive value and economy. The results are summarized as follows: 1) Flours from naked barley, sweet potato, potato, corn, defatted rice bran and defatted soybean were compared in respect of their proximate composition, thiamine content and protein score. 2) In color comparison, naked barley and defatted soy flours were comparable to wheat flour whereas corn and sweet potato flours were a little inferior. In raising power, naked barley and defatted soy flours were similar to wheat flour and others were inferior. 3) In maximum viscosity of flours by amylograph, naked barley, corn and potato flours were higher than wheat flour and others were lower. In viscosity in cooling, corn flour was similar to wheat flour and naked barley and potato flours were lower. Addition of $10{\sim}20%$ defatted soy flour into other flours generally caused the lowering of viscosity. Addition of emulsifiers such as glyceryl monostearate, calcium stearyl lactylate, Methocel and Emulthin into the flours manifested different effects on the amylogram. 4) In nutritional test by rat, diets consisting of naked barley, sweet potato, potato or corn flours, each containing defatted soy flour (at 10% level with exception of 20% for sweet potato flour) and naked barley flour fortified with lysine were similar to wheat flour in digestibility, but were superior in NPU and biological value. 5) In price estimation, sweet potato and corn flours were competitive with wheat flour, but naked barley flour was a little expensive. On the other hand, barley and sweet potato are promising in terms of domestic production.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.461-475
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• 2006

In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.

• Journal of radiological science and technology
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• v.37 no.3
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• pp.187-193
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• 2014

The purpose of this study was to analyze the effect on the selectivity on of high-voltage rectification device that measured the performance of the grid, and the contrast improvement ability (K factor) by measuring the scattered radiation content of the transmitted X-rays. The scattered radiation generated when the X-ray flux comes from the diagnostic X-ray generator that passes through an object. Targeting four different rectifications of X-ray generators, the mean value of the tube voltage and the tube current was measured in order to maximize the accuracy of the generating power dose within the same exposure condition. Using fluorescence meter, the content of the scattered rays that are transmitted through the acrylic was measured depending on the grid usage. When grid is not used, the content of the scattered rays was the lowest (34.158%) with the single-phase rectifier, was increased with the inverter rectifier (37.043%) and the three-phase 24-peak rectification method (37.447%). The difference of the scattered radiation content of each device was significant from the lowest 0.404% to the highest 3.289% while using 8:1 grid, the content of the scattered ray was the lowest with the single content of the scattered ray was the lowest with the single-phase rectifier (18.258%), was increased with the rectifier (25.502%) and the 24-peaks rectification (24.217%). Furthermore, there was difference up to content 7.244% to the lowest content 1.285% within three-phase 24-peaks rectification, inverter rectifications, and single-phase rectifier depending on the selectivity of the grid. Drawn from the statistical analysis, there was a similar relationship between the contrast improvement factor and the K factor. As a result, the grid selectivity and the contrast were increased within the single-phase rectifier rather than the constant voltage rectifier.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.304-313
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• 2016

One of the issues currently facing nuclear power plants is how to store spent nuclear waste materials which are contaminated with radionuclides such as $^{134}Cs$, $^{135}Cs$, and $^{137}Cs$. Bioremediation processes may offer a potent method of cleaning up radioactive cesium. However, there have only been limited reports on $Cs^+$ tolerant bacteria. In this study, we report the isolation and identification of $Cs^+$ tolerant bacteria in environmental soil and sediment. The resistant $Cs^+$ isolates were screened from enrichment cultures in R2A medium supplemented with 100 mM CsCl for 72 h, followed by microbial community analysis based on sequencing analysis from 16S rRNA gene clone libraries(NCBI's BlastN). The dominant Bacillus anthracis Roh-1 and B. cereus Roh-2 were successfully isolated from the cesium enrichment culture. Importantly, B. cereus Roh-2 is resistant to 30% more $Cs^+$ than is B. anthracis Roh-1 when treated with 50 mM CsCl. Growth experiments clearly demonstrated that the isolate had a higher tolerance to $Cs^+$. In addition, we investigated the adsorption of $0.2mg\;L^{-1}$ $Cs^+$ using B. anthracis Roh-1. The maximum $Cs^+$ biosorption capacity of B. anthracis Roh-1 was $2.01mg\;g^{-1}$ at pH 10. Thus, we show that $Cs^+$ tolerant bacterial isolates could be used for bioremediation of contaminated environments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.73-78
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• 2022

This experiment was conducted to establish the technology for artificial hay preparation in Korea. Using far-infrared heater, a device that can control temperature, airflow, and far-infrared radiation was produced and conducted on the fourth harvested alfalfa. The drying conditions were carried out by selecting a total of four conditions. For each condition, the radiation rate was set to around 40% (33-42%), and the temperature was set at 58~65℃, and the speed of the airflow was fixed at 60m/s. The overall drying time was set to 30 min in the single and 60 min (30-30 min) and 90 min (30-30-30 min) in the complex condition, and the radiation rate and temperature were changed by time period. In the case of drying condition 1, the final dry matter (DM) content was 46.26%, which did not reach a DM suitable for hay. However, all of the alfalfa corresponding to the remaining drying conditions 2 to 7 showed a DM content of 80% or more, resulting in optimal alfalfa hay production. In power consumption according to the drying conditions, the second drying condition showed the lowest at 4.7 KW, and the remaining drying conditions were as high as 6.5 to 7.1 KW. The crude protein content was found to be high at an average of 25.91% and it showed the highest content in the 5th drying condition (26.93%) and the lowest value in the 6th drying condition (25.16%). The digestibility showed a high value with an average of 84.90%, and there was no significant difference among treatments (p>0.05). Considering the above results, it was judged that drying condition 2 was the most advantageous.