• Journal of Biosystems Engineering
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• 제43권4호
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• pp.303-310
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• 2018

Purpose: This research was conducted to determine the design factors of a seed-metering device for the development of a seeder. The device allows the seeder to sow precisely one to three seeds of foxtail millet and sorghum. To obtain fundamental information regarding the design of the seed-metering device, examination of the physical properties of foxtail millet and sorghum was conducted. Methods: Based on the results of an adaptability test using an existing seeder with foxtail millet and sorghum, an experimental roller-type seed-metering device was made. The seeding factors considered during the experiment were the width, length, and depth, as well as the shape of the groove in the seed-metering roller. By adapting an analysis of variance, the experimental results of the seeding factors were analyzed. Results: The measured results of the respective lengths and widths of the seeds were 2.11 and 1.64 mm for foxtail millet, and 3.68 and 3.32 mm for sorghum, respectively. The weight of 1,000 seeds was 2.43 g for foxtail millet and 17.5 g for sorghum. The seeds were of an elliptical shape, considering the length and width. A sieve analysis showed that the size distribution of foxtail millet was quite regular whereas that of sorghum was irregular. Conclusions: The seeding results showed that the rates of incorrect planting were low when the groove of the roller-type metering device is an elliptical type. To sow one to three seeds, the groove of roller-type metering devices $2.0mm{\times}4.0mm{\times}1.5mm$ ($width{\times}length{\times}depth$) for foxtail millet, and $4.0mm{\times}8.0mm{\times}3.0mm$ and $4.5mm{\times}8.0mm{\times}3.0mm$ ($width{\times}length{\times}depth$) for Sorghum.

• 한국전자파학회논문지
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• 제30권1호
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• pp.45-53
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• 2019

본 논문에서는 다이폴, 슬롯, 패치 세 가지 기본타입 안테나 소자를 이용하여 28 GHz 5G 단말용 배열안테나를 설계하고 성능을 비교 분석하였다. 안테나 소자 간 격리도는 $S_{21}$을 기준으로 비교하였으며, 다이폴, 슬롯, 패치 타입이 각각 -13.76 dB, -16.88 dB, -11.47 dB로 슬롯 타입 안테나가 가장 높은 격리도 특성을 갖는다. 또한 빔 커버리지 성능 비교를 위하여 배열안테나의 빔 폭, 최대 빔 조향 각도 등의 성능을 분석하였다. 최대 빔 조향 각도는 슬롯 타입이 $63^{\circ}$로 가장 넓고, 패치 타입이 $36^{\circ}$로 가장 좁은 조향 특성을 가진다. 실제 단말기 사용 환경에서의 안테나 성능을 확인하기 위해서 단말기가 talk mode와 data mode에서 동작할 때의 특성을 시뮬레이션을 통해 분석하였다. 비교 분석 결과, 28 GHz 5G 단말용 배열안테나 소자로 슬롯 타입 배열안테나가 가장 적합한 것을 확인하였다.

• 한국기후변화학회지
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• 제6권2호
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• pp.113-119
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• 2015

Emission from the traditional Korean fireplace, or the under-floor heating and cooking device, can contribute significantly to airborne pollutants inventories. This study has systematically measured emissions of airborne pollutants from the fireplace when used different fuels such as firewood, agricultural crop residuals, household wastes. The results show that emission factors of airborne pollutants through the primary combustion of firewood were 3.22 g/kg for TSP, 2.93 g/kg for $PM_{10}$, 2.65 g/kg for $PM_{2.5}$, 174.19 g/kg for CO, 7.77 g/kg for NO, 0.15 g/kg for $SO_2$, 40.53 g/kg for TVOC and 0.03 g/kg for $NH_3$; from burning of agricultural crop residues, 2.85 g/kg for TSP, 1.38 g/kg for $PM_{10}$, 1.14 g/kg for $PM_{2.5}$, 126.47 g/kg for CO, 12.60 g/kg for NO, 0.20 g/kg for $SO_2$, 33.73 g/kg for TVOC and 0.02 g/kg for $NH_3$; and for household wastes, 10.52 g/kg for TSP, 8.52 g/kg for $PM_{10}$, 6.23 g/kg for $PM_{2.5}$, 72.86 g/kg for CO, 11.73 g/kg for NO, 0.20 g/kg for $SO_2$, 47.10 g/kg for TVOC and 0.20 g/kg for $NH_3$.

• 한국대기환경학회지
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• 제20권2호
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• pp.205-213
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• 2004

The emission characteristics of mercury in waste incinerators were investigated to get basic data for the policy development on the emission reduction of mercury (Hg). For the study several important factors were analysed from 4 incinerators such as mercury concentration, emission factors and removal rate for control devices. The results are listed below. Mercury concentrations in the flue gas were 0.39～5.96 $\mu\textrm{g}$/S㎥ in MWI and 2.5～8.8 $\mu\textrm{g}$/S㎥ in IWI. The distributions of gaseous and particulate mercury in flue gas were above 99% and below 1 %, respectively. Therefore, in order to remove mercury effectively, it is important to control the gaseous mercury. Mercury concentrations in fly ash collected from control device were found as 16.2～35.6 mg/kg- ash in FF of MWI. Also mercury concentrations at the front and back point of control device of MWI were 33.45～62.65 $\mu\textrm{g}$/S㎥ and 0.88～3.49 $\mu\textrm{g}$/S㎥, respectively. Emission factors were estimated as 3.67～11.67 mg/ton in FF, 2.6～24.5 mg/ton in MWI with SNCR, SDR and FF, 54.9～192.7 mg/ton in IWI with Cyclone and FF. Emissions from Municipal Waste Incinerator were found both in minimum and maximum ranges. Annual mercury emissions emitted from MWI was estimated as 20.0 kg (6.0～33.9 kg).

• 디지털산업정보학회논문지
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• 제15권3호
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• pp.1-14
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• 2019

The 4th Industrial Revolution, intelligent automobile application technology is evolving beyond the limit of the mobile device to a variety of application software and multi-media collective technology with big data-based AI(artificial intelligence) technology. with the recent commercialization of 5G mobile communication service, artificial intelligent automobile technology, which is a fusion of automobile and IT technology, is evolving into more intelligent automobile service technology, and each multimedia platform service and application developed in such distributed environment is being developed Accordingly, application software technology developed with a single system SoC of a portable terminal device through various service technologies is absolutely required. In this paper, smart device design for ontology design of intelligent automobile open platform enables to design intelligent automobile middleware software design technology such as Android based SVC Codec and real time video and graphics processing that is not expressed in single ASIC application software technology as SoC based application designWe have experimented in smart device environment through researches, and newly designed service functions of various terminal devices provided as open platforms and application solutions in SoC environment and applied standardized interface analysis technique and proved this experiment.

• 디지털산업정보학회논문지
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• 제15권3호
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• pp.29-36
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• 2019

With the rapid development of 5G technology, more and more network functions are interconnected and more popular. In order to effectively manage emerging network concepts, it allows any device object in the real world to be connected anywhere and at any time through the integration of device object recognition, interaction and raw data collection technologies. In addition, IP Multimedia Subsystem (IMS) is an architecture framework for transmitting IP-based information to the device object which can be represented as end user. Therefore, the Internet of Things and IP Multimedia Subsystem (IoT-IMS) communication platform can provide a convenient and fast way for user or device objects to deploy new application services effectively. In particular, in order to collect and manage the device information from IoT effectively in the IoT-IMS communication platform, an IoT Information Gateway (IIG) is proposed. Through the IoT Application Service (AS) scenario, the collected device information can be easily observed and managed in a unified way.

• 한국초전도ㆍ저온공학회논문지
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• 제25권2호
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• pp.14-18
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• 2023

Superconducting layers deposited on the metal substrate using the pulsed laser deposition process (PLD) play a crucial role in exploring new applications of superconducting wires and enhancing the performance of superconducting devices. In order to improve the superconducting property and increase the throughput of superconducting wire fabricated by pulsed laser deposition, high temperature heating device is needed that provides high temperature stability and strong durability in high oxygen partial pressure environments while minimizing performance degradation caused by surface contamination. In this study, new heating device have been developed for PLD process that deposit and growth the superconducting material continuously on substrate using reel-to-reel transportation apparatus. New heating device is designed and fabricated using iron-chromium-aluminum wire and alumina tube as a heating element and sheath materials, respectively. Heating temperature of the heater was reached over 850 ℃ under 700 mTorr of oxygen partial pressure and is kept for 5 hours. The experimental results confirm the effectiveness of the developed heating device system in maintaining a stable and consistent temperature in PLD. These research findings make significant contributions to the exploration of new applications for superconducting materials and the enhancement of superconducting device performance.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권4호
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• pp.262-269
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• 2005

Semiconductor scientists and engineers ideally desire the faster but the cheaper non-volatile memory devices. In practice, no single device satisfies this desire because a faster device is expensive and a cheaper is slow. Therefore, in this paper, we use heterogeneous non-volatile memories and construct an efficient hierarchy for them. First, a small RAM device (e.g., MRAM, FRAM, and PRAM) is used as a write buffer of flash memory devices. Since the buffer is faster and does not have an erase operation, write can be done quickly in the buffer, making the write latency short. Also, if a write is requested to a data stored in the buffer, the write is directly processed in the buffer, reducing one write operation to flash storages. Second, we use many types of flash memories (e.g., SLC and MLC flash memories) in order to reduce the overall storage cost. Specifically, write requests are classified into two types, hot and cold, where hot data is vulnerable to be modified in the near future. Only hot data is stored in the faster SLC flash, while the cold is kept in slower MLC flash or NOR flash. The evaluation results show that the proposed hierarchy is effective at improving the access time of flash memory storages in a cost-effective manner thanks to the locality in memory accesses.

• Transactions on Electrical and Electronic Materials
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• 제16권5호
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• pp.254-259
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• 2015

This paper reports the optimized mixed-signal performance of a high-voltage (HV) laterally double-diffused metaloxide-semiconductor (LDMOS) field-effect transistor (FET) with a dual gate oxide (DGOX). The fabricated device is based on the split-gate FET concept. In addition, the gate oxide on the source-side channel is thicker than that on the drain-side channel. The experiment results showed that the electrical characteristics are strongly dependent on the source-side channel length with a thick gate oxide. The digital and analog performances according to the source-side channel length of the DGOX LDMOS device were examined for circuit applications. The HV DGOX device with various source-side channel lengths showed reduced by maximum 37% on-resistance (R_ON) and 50% drain conductance (g_ds). Therefore, the optimized mixed-signal performance of the HV DGOX device can be obtained when the source-side channel length with a thick gate oxide is shorter than half of the channel length.

• 정보와 통신
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• 제32권4호
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• pp.80-86
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• 2015

본고에서는 급증하는 단말과 모바일 트래픽을 수용하기 위한 방안으로 이동형 개인셀에 대해 알아본다. 이동형 개인셀은 사용자 중심의 네트워킹 실현을 위한 주요 기술 중 하나로, IoT(Internet of Things)의 실현 등으로 인한 모바일 단말의 급격한 증가를 수용하기 위한 후보 기술로 연구되고 있다. 본고에서는 5G 요구사항 중 기존 4G 시스템 대비 1000배의 단말 수용을 위해 이동형 개인셀의 활용 가능성을 검토하고자 한다.