• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.18-19
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• 2008

Polycrystalline(poly) 3C-SiC film is a promising structural material for M/NEMS used in harsh environments, bio and fields. In order to realize poly 3C-SiC based M/NEMS devices, the electrical properties of poly 3C-SiC film have to be optimized. The n-type poly 3C-SiC thin film is deposited by APCVD using HMDS$(Si_2(CH_3)_6)$ as single precursor and are in-situ doped using N2. Resistivity values as low as 0.014 $\Omega$cm were achieved. The carrier concentration increased with doping from $3.0819\times10^{17}$ to $2.2994\times10^{19}cm^{-3}$ and electronicmobility increased from 2.433 to 29.299 $cm^2/V{\cdot}s$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1470-1471
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• 2008

We present a front-side micromachined thermopile with high sensitivity in the 3-5${\mu}m$ window, and discuss its application to a novel non-dispersive infrared (NDIR) $CO_2$ gas sensor with a light source emitting collimated light. The micromachined thermopile shows a measured sensitivity of 30 mV/W and a $D^*$ of $0.3{\times}10^8cm^{\surd}Hz/W$. Using this newly fabricated thermopile, we also have successfully developed a small, sensitive NDIR $CO_2$ detector module for accurate air quality monitoring systems in energy-saving building and automotive applications. The novel sample cavity comprising specular reflectors around the light bulb is configured to uniformly emit collimated light into the entrance aperture of the cavity in order to enhance the sensitivity of NDIR $CO_2$ detector.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.554-554
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• 2000

To improve mechanical properties of Cu-Al-Ni alloy by the grain refinement, Cu-Al-Ni SMA ribbons were fabricated by melt spinning apparatus. The variations of microstructure, mechanical properties and transformation characteristics with the condition of rapid solidification and annealing time-temperature were investigated in Cu-Al-Ni SMA ribbons. The ribbons fabricated by melt spinning obtained around 1.5nm in width and 50-60${\mu}{\textrm}{m}$ in thickness. With increasing wheel speed in order of 10m/s, 15m/s, 20m/s, 30m/s and 3m/s, the grain size was decreased in order of 10${\mu}{\textrm}{m}$, 6.25${\mu}{\textrm}{m}$, 5.5${\mu}{\textrm}{m}$, 3${\mu}{\textrm}{m}$ and 3${\mu}{\textrm}{m}$. $M_{s}$ and $A_{s}$ temperature were decreased with decreasing grain size. By X-ray diffraction test, ordered $\beta$$_1$ phase was observed in all the SMA ribbons and the volume friction of it was increased with increasing wheel speed. With increasing wheel speed, strain was increased from 4.2% to 5.8% and fracture mode has changed from mixture of intergranular and dimple fracture to mixture of fiber structure and dimple fracture. The grain size of ribbon heat-treated at $600^{\circ}C$ was increased with increasing time. In the heat-treated ribbons at 55$0^{\circ}C$, ${\gamma}$$_2$ phases were observed.d.d.

• 한국컴퓨터정보학회논문지
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• 제22권7호
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• pp.63-74
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• 2017

Recently in the area of ICT, the M2M and IoT are in the spotlight as a cutting edge technology with the help of advancement of internet. Among those fields, the smart home is the closest area to our daily lives. Smart home has the purpose to lead a user more convenient living in the house with WLAN (Wireless Local Area Network) or other short-range communication environments using automated appliances. With an arrival of the age of IoT, this can be described as one axis of a variety of applications as for the M2H (Machine to Home) field in M2M. In this paper, we propose a novel technique for estimating the location of a terminal that freely move within a specified area using the RSSI (Received Signal Strength Indication) in the WLAN environment. In order to perform the location estimation, the Fingerprint and KNN methods are utilized and the LMS with the gradient descent method and the proposed algorithm are also used through the error correction functions for locating the real-time position of a moving user who is keeping a smart terminal. From the estimated location, the nearest fixed devices which are general electric appliances were supposed to work appropriately for self-operating of virtual smart home. Through the experiments, connection and operation success rate, and the performance results are analyzed, presenting the verification results.

• International Journal of Computer Science & Network Security
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• 제21권2호
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• pp.21-39
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• 2021

The acceptance of smartphone applications in the learning field is one of the most significant challenges for higher education institutions in Saudi Arabia. These institutions serve large and varied sectors of society and have a tremendous impact on the knowledge gained by student segments at various ages. M-learning is of great importance because it provides access to learning through a wide range of mobile networks and allows students to learn at any time and in any place. There is a lack of quality requirements for M-learning applications in Saudi societies partly because of mandates for high levels of privacy and gender segregation in education (Garg, 2013; Sarrab et al., 2014). According to the Saudi Arabian education ministry policy, gender segregation in education reflects the country's religious and traditional values (Ministry of Education, 2013, No. 155). The opportunity of many applications would help the Saudi target audience more easily accept M-learning applications and expand their knowledge while maintaining government policy related to religious values and gender segregation in the educational environment. In addition, students can share information through the online framework without breaking religious restrictions. This study uses a quantitative perspective to focus on defining the technical aspects and learning requirements for distributing knowledge among students within the digital environment. Additionally, the framework of the unified theory of acceptance and use of technology (UTAUT) is used to modify new constructs, called application quality requirements, that consist of quality requirements for systems, information, and interfaces.

• Journal of the Korean Wood Science and Technology
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• 제41권1호
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• pp.77-86
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• 2013

본 연구는 목조주택의 건물에너지 성능을 평가하고 개선하기 위해 수행되었다. 목조주택의 에너지 요구량을 산정하기 위하여 CE3 (Construction Energy Efficiency Evaluation) 웹기반 소프트웨어를 사용하였고 그 결과 대상 주택의 연간 난방에너지 요구량은 바닥면적 1 $m^2$당 160 kWh로 계산되었다. 난방에너지 요구량을 줄이기 위해 다음 4가지의 에너지 절감방법을 채택하였다; a) 건물형태의 단순화, b) 창호면적의 축소, c) 고성능 창호의 적용, d) 폐열회수환기장치의 적용. 열관류율 1 $W/m^2{\cdot}K$의 고성능창호로 교체할 경우 대상 주택의 난방에너지 요구량은 80 $kWh/m^2{\cdot}a$로 감소하였다. 4가지 방법을 조합하여 적용하면 고성능창호와 폐열회수환기장치를 함께 적용하였을 때 난방에너지 요구량은 34.5 $kWh/m^2{\cdot}a$로 감소하여 가장 우수한 성능을 나타냈다.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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• pp.868-874
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• 2007

Mobile Government is one of the new and important developments in e-government. The promise of m-government to provide greater access to government information is progressing in many developed and developing countries. Current Mobile Government does not exploit the full potential of available technology. Research shows there is a lack of a perfect killer application [2][1]. Firstly, this paper begins with an overview of e-gov and m-gov. In this context, this paper aims to present a framework to find killer applications in M-government to which researchers must pay attention and develop suitable way to perform according to different countries' contexts.

• 품질경영학회지
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• 제22권2호
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• pp.127-142
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• 1994

In these days, the PCs are widely used in the mid-level factory. But they have low-effectiveness for using them. The main reason should be the lack of useful and practical software in the market. This Case study aimed at the support of the software using DB Language to get M/M chart for aquiring work study and standard time data in the mid-level factory having multi-item and multi-process type. CVA (Chronocycle Video Analysis) is applied to get basic standard time data and working list. Standard time, Sequence of working and allowance time or rate for man and machine will be readily obtained through the menu when the software executing. Detailed program list is systematically shown in Appendix.

• Journal of Biosystems Engineering
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• 제23권2호
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• pp.105-114
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• 1998

Granule application with a boom has merits of accurate application and high field efficiency. In order to develop a boom granule applicator, aerodynamic properties of agrichemicals should be investigated. This study was accomplished to investigate aerodynamic properties of granules and factors affecting on them. The tested agrichemicals were urea, compound fertilizer (17-21-17), sand and zeolite. Basic physical properties of granules such as true density, sphericity, and arithmetic mean diameter for those materials were analyzed. Regression equations for pickup velocity (v$_{p}$) and saltation velocity (v$_{s}$) were proposed by the data transformation and the multi-regression analysis as follows : (equation omitted) where, 0< s < 1, 0< λ$_{i}$< 3, 35 < D/d$_{p}$ < 350, 1000 $_{p}$/p$_{a}$ < 2500 The range of pickup velocity of fertilizers and other agrichemicals were shown to be 10-16m/s and 9-13m/s, respectively. The saltation velocity of fertilizer and other agrichemicals were 3 m/s and 4 m/s, respectively.y.ively.y.y.

• 디지털융복합연구
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• 제13권10호
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• pp.343-351
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• 2015

현재 M2M 환경은 다양한 서비스가 기관 및 기업이나 일상생활로 확대되면서 관련 기술의 보안 취약성 발생 가능성이 이슈화되고 있다. 본 논문은 이러한 보안 취약성 문제를 해결하기 위해 M2M 환경의 디바이스 키 보호를 위한 암호 알고리즘 응용 기법을 제안한다. 제안 기법은 타원곡선 암호 기반으로 초기 키 교환과 서명 교환을 통해 보안 세션을 생성하였고, 화이트박스 암호는 보안 세션 키를 이용하여 화이트박스 테이블을 생성하는 암호화에 응용하였다. 암호 알고리즘 적용 결과, 타원곡선 암호는 통신 세션에 대한 경량 화된 상호인증, 세션 키 보호를 제공하고, 화이트 박스 암호는 기존 암호 알고리즘과는 다른 방식으로 암호화에 사용되는 세션 키 보호를 보장하였다. 제안하는 프로토콜은 데이터변조 및 노출, 중간자 공격, 데이터 위조 및 변조 공격에 대해 안전한 장점이 있다.