• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.669-672
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• 2015

Recent Internet of Things (IoT, Internet of Things) that can be applied to various fields as the development of technology has been developed a lot of service and has been developed with the service also for crop management. To manage the essential elements of soil moisture in the crop growth but existing a direct person measuring the fluid point to carry the measuring instrument, if you take advantage of the WPAN (Wireless Personal Area Network) in this paper to manage sensor data, a fixed 3 points (30, 60, 90 cm) and can be managed can be scientifically analyzed the state of growth of the crop. Open field environment is utilized as it is less disturbance of the interference and the frequency of the radio frequency signal of the structure provides a relatively comfortable environment. Therefore, WPAN building and data transmission scheme of the minimum cost is to be developed. In addition, the operation to enter low power mode, the algorithm is necessary because a lot of restrictions on the power supply applied to the sensor nodes and the gateway is constructed in the open field. In the experiment, verifying the effectiveness by using a network configuration of each of the sensor nodes and the gateway, and provides a method for time synchronization of the operation and a low power mode. The study protocol for the RF communication with the LoRa and to enhance communication efficiency is needed in the future.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.29-30
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• 2001

자연에너지원중 태양에너지를 이용한 자갈축열 태양열 온실의 난방에너지 절감효과를 분석하기 위하여 야간에 내부설정온도를 18℃로 했을 때의 자갈축열 태양열 온실과 동일한 제원의 대조온실의 난방연료소비량을 비교하였다. 자갈축열 태양열 온실의 경우 난방초기에는 연료가 대조온실에 비해 약 10%정도 더 소모되었으나 2일이 경과한 후에는 점차 난방연료소비량이 감소하였다(Fig. 2) 이러한 결과는 자갈축열 태양열 온실의 경우 주간에 온실에 투여되는 일사에 의해 축열이 이루어 질뿐만 아니라 야간에 난방을 할 경우에도 축열층의 온도가 설정온도에 도달할 때까지 축열이 이루지기 때문인 것으로 분석되었다 (Fig. 1). 3월 10일부터 3월 15일까지 6일간의 난방연료소비량이 대조온실은 167℃였으나, 자갈축열 태양열 온실은 109℃로써 대조온실에 비해 약 35%정도 난방연료 절감효과가 있는 것으로 분석되었다(Fig. 2). 6일간의 난방 후 자갈축열 태양열 온실에 난방을 중단한 결과 온실외부의 최저기온이 -2.4℃일 때 자갈축열 태양열 온실의 내부최저온도는 14℃를 유지하였으며, 이후 계속 난방을 수행하지 않은 상태에서도 주간에 축열효과로 인하여 최저외기온이 3℃전후일 때 자갈축열 태양열 온실의 내부온도는 15℃를 유지하였으나 대조온실은 5℃ 전후였다. 그리고, 일기온차가 심한 3월말에는 야간설정온도가 18℃인 경우에 자갈축열 태양열 온실의 난방연료소비량이 대조온실에 비해 월등히 적음을 알 수 있었다(Fig. 1, 2). 3월에 자갈축열 태양열 온실의 난방연료소비량은 대조온실에 비해 약 50%이상의 절감효과가 있는 것으로 나타났다./TEX>3.1cm, 2cm$\times$4.2cm 순으로 나타났다. 5. 저고리의 옆길이 곡선에 대한 평가는 진종의 중심인 겨드랑이가 5cm인 것이 가장 우수한 것으로 나타났으며, 그 다음으로 4cm, 6cm, 3cm 순으로 나타났다. 6. 이에 위의 항목들을 종합하여 제작한 연구저고리는 등길이가 28cm, 어깨선 위치는 1.75cm, 깃크기는 5cm$\times$21.5cm, 소매통 크기는 3cm$\times$4.3cm, 옆길이 곡선은 5cm로써 그 형태에 따른 신체적합성에 대한 외관 관능검사 결과로 3.83의 평균값으로 나타났고, 심미성에 대한 외관 관능검사를 항목별 평균치 값으로 종합하면 4.00의 값으로 나타났다. 또한 각 부위별 동작적합성 관능검사는 7가지 동작을 부위별 항목 평균치 결과 3.95의 유수한 저고리로 평가되었다. 본 연구 실험 결과 앞으로도 전통 저고리를 피복함에 있어 외관과 동작적합성이 좋은 저고리를 만들기 위해 지속적 연구가 요청된다. turned back than the Korean women's. Based on the above findings, a torso prototype was developed for the Chinese women by setting the body measurements in reference with their average body measurements plus minimum reserve. The reference lines were set for front/back central line, front/

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.2
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• pp.99-106
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• 1987

Annealing were performed to investigate the behaviors of the residual stress remaining on the member of a steel structure. According to the fatigue test, the welding part has higher fatigue crack growth rate than the base metal part because the hardening of welding part reduce fracture toughness. However, the heat treatment decrease the hardness and increase the resistance to failure. Thus, the fatigue crack growth rate is improved and it reaches the minimum at $650^{\circ}C$. Elber' s equation includes the effect of the crack-close so that this equation provides a lower the fatigue crack growth rate than Paris-Erdogan' s equation, the Elber's curves show no significant difference to indentify the effect of the residual stress. The Pop loading along the crack length increases as the hardness goes higher. The heat treatment not only decrease the hardness, and the fatigue crack growth rate, but increase the absorption energy and fracture toughness on the member of a steel structure. As the result, the heat treatment produces the resistant ability to cracking which can reduce the degree of danger to failure.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.15-20
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• 2010

In this study, AZO (Al: 3 wt%) thin films have been prepared on PES Plastic substrates at various working pressure (5~20 mTorr), $O_2$ gas flow rate(0~3%) and the fixed substrate temperature of 200 f by using the RF magnetron sputtering and their optical and electrical properties have been studied. The XRD measurement shows that AZO thin films exhibit c-axis preferred orientation. From the results of AFM measurements, it is known that the lowest surface roughness (3.49 nm) is obtained for the AZO thin film fabricated at 5 mTorr of working pressure and 3% of $O_2$ gas flow rate. The optical transmittance of AZO thin films is measured as 80% in the visible region. We observe that the energy band gap of AZO thin films increases with decreasing the working pressure and the $O_2$ gas flow rate. This phenomenon is due to the Burstein-Moss effect. Hall measurement shows that the maximum carrier concentration ($2.63\;{\times}\;10^{20}\;cm^{-3}$) and the minimum resistivity ($4.35\;{\times}\;10^{-3}\;{\Omega}cm$) are obtained for the AZO thin film fabricated at 5mTorr of working pressure and 0% of $O_2$ gas flow rate.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.1
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• pp.1-8
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• 1999

In recent years, concern has been raised about the technique of controlling electrical breakdown by using laser in many fields. Especially, laser has attracted much attention in the Electro-Discharge Machining(EDM) because of its many rrents. 1berefore, this research has been perfonred to obtain fundarrental data for the discharge guide technology by a pulsed Nd:YAG laser which can be awJied to discharge processing machining. 1be experilnnts of laser-guided de discharge have been carried out at low air pressure ranging from 0.2 to 20 torr. The minimum laser-guided de discharge voltage $V_{G.min}$ at the given pressures P and distances d between an anode and a cathode was rreasured It is found that $V_{G.min}$ is much lower than the natural discharge voltage $V_{ND}$, and the values of VGrrin and $V_{ND}$ as a function of P.d has a similar tendency. The laser output energy $E_{out}$ decreases with input pulse duration $t_p$ increasing, and the rrore the value of $t_p$ increases, the higher that of V$V_{G.min}$ is obtained because the number of photons N decreases with $t_p$ increasing. In addition, the laser-guided de discharge range and the discharge guide characteristics as laser outpIt $E_{out}$ was investigated.igated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1745-1753
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• 2008

We analyzed the physical and chemical properties such as proximate analysis, ultimate analysis, heating values, thermogravimetric analysis, and combustion test for the organic sludge discharged from chemical and petrochemical product manufacturing industries in the industrial complex. The average combustible and ash content of organic sludges from chemical and petrochemical product manufacturing industries were 17.42%, 7.45%, and 18.25%, 4.22%, respectively. The C, H, O, N, and S compositions for chemical and petrochemical product manufacturing industries were 33.06, 4.34, 24.81, 5.18, and 0.72%. And those compositions for petrochemical product manufacturing industries were 36.58, 4.74, 26.79, 5.09, and 0.49%, respectively. From the TGA test, the minimum temperature for combustion of the sludge discharged from B company was $700^{\circ}C$ for direct use for energy and 2 sludges(F and N companies) were about $600^{\circ}C$. According to the basic combustion test, high concentration of CO was formed because oxidation and pyrolysis reaction take place in the batch type reactor at the same time. From this phenomena we could obtain the significant data for the overheating and breakage of furnace.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.871-878
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• 2004

Pulsed electric fields(PEF) technology is one of the latest nonthermal methods of food processing for obtaining safe and minimally processed foods. This technology can be effectively explored for obtaining safe food with minimum effect on nutritional, flavor, rheological and sensory qualities of food products. The process involves the application of high voltage(typically 20 ${\sim}$ 80 kv/cm) to foods placed between two electrodes. The mode of inactivation of microorganism; by PEP processing has been postulated in term; of electric breakdown and electroporation. The extent of destruction of microorganisms in PEF processing depends mainly on the electric field strength of the pulses and treatment time. For each cell types, a specific critical electric field strength and specific critical treatment time are required depending on the cell characteristics and the type and strength of the medium where they have been present. The effect also depends on the types of microorganisms and their phase of growth. A careful combination of processing parameters has to be selected for effective processing. The potential applications of PEF technology are numerous ranging from biotechnology to food preservation. With respect to food processing, it has already been established that, the technology is non-thermal in nature, economical and energy efficient, besides providing minimally processed foods. This article gives a brief overview of this technology for food processing applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1128-1134
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• 2007

Recently, sensor network technology is a highly concerned area due to the expectation of many applications in various fields. The application of sensor network technology to the marine and ocean surveillance and investigation makes the marine environmental research easier since intelligent sensor nodes substitute the human labor work. In ocean sensor network, the localization scheme for the sensor nodes is most essential because all the information without from sensor nodes might be useless unless the positional information of each sensor nodes is provided. In this paper, the localization scheme with mobile beacons in ocean sensor networks is suggested and showed it could be effective for applying to marine circumstances. Even though the previous localization scheme(Ssu's) has advantages that additional hardware is not required for obtaining the information of distance and angle and shows the high accuracy of location and energy efficiency and easy expandability as well, it has also demerits the location error increases as the minimum distance between the absolute positional information become closer. In our works, the improved localization scheme with the presumed area of sensor node using geometric constraints is suggested.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1021-1030
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• 2010

In the sensor network, many tiny nodes construct Ad-Hoc network using wireless interface. As this type of system consists of thousands of nodes, managing each sensor node in real world after deploying them is very difficult. In order to install the sensor network successfully, it is necessary to verify its software using a simulator beforehand. In fact Sensor network simulators require high fidelity and timing accuracy to be used as a design, implementation, and evaluation tool of wireless sensor networks. Cycle-accurate, instruction-level simulation is the known solution for those purposes. In this paper, we developed an instruction-level sensor network simulator for Telos sensor node as named TeloSlM. It consists of MSP430 and CC2420. Recently, Telos is the most popular mote because MSP430 can consume the minimum energy in recent motes and CC2420 can support Zigbee. So that TeloSlM can provide the easy way for the developers to verify software. It is cycle-accurate in instruction-level simulator that is indispensable for OS and the specific functions and can simulate scalable sensor network at the same time. In addition, TeloSlM provides the GUI Tool to show result easily.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.75-84
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• 2009

The effect of various SNPs (silver nanoparticles) on the growth of Microcystis aeruginosa was investigated in laboratory and field experiment. Four SNPs, namely JS47N, JS47N-K2, JS47N/3-1 and JS47N/3-2 were used to this study. The Ag size, concentration and color of these solutions were about $20{\sim}40nm$, $200mg\;L^-1$ and brown, respectively. At 0.01 and $0.1mg\;L^-1$, SNPs inhibited the growth of unicellular M. aeruginosa by 99.4% and 99.9%, respectively. However, SNPs of $1mg\;L^-1$ inhibited the growth of colonial M. aeruginosa by 98.5%, whereas the other three concentrations (0.001, 0.01 and $0.1mg\;L^-1$) had little inhibitory effect. In experimental enclosures from eutrophic lake, cyanobacteria including M. aeruginosa were found to be more sensitive to the SNPs than green algae and diatoms. In conclusion, our study indicates that SNPs has a selective cyanocidal potential when used to M. aeruginosa. We believe that future studies need to test on various other organisms, and determine minimum concentration for field application.