• 한국인터넷방송통신학회논문지
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• 제20권2호
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• pp.55-60
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• 2020

본 논문에서는 재난이 발생하였을 경우 재난 정보를 스마트폰에서 확인할 뿐만 아니라 근거리 무선통신을 활용한 웨어러블 기기에서 동시에 확인할 수 있는 방안에 대해 연구를 진행하였다. 통상적으로 사용하는 웨어러블 기기는 무선 이어폰, 스마트밴드, 스마트워치와 같은 기기들이 있다. 이러한 기기 중에서 재난 발생 시 사용자가 재난 정보를 눈으로 확인할 수 있는 기기로는 스마트워치가 있다. 하지만 현재 재난문자는 스마트폰에서만 확인할 수 있기 때문에 스마트폰에서 수신 받은 재난 정보를 스마트워치로 전달하는 방안에 대하여 연구를 진행하였다. 본 논문과 같은 연구가 지속될 경우 재난 발생 시 다양한 환경에서 재난을 인지하고 재난에 대한 대비를 수행할 수 있을 것이다.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.96-97
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• 2000

Incoherent broadband optical sources have been applied in various areas such as a light source for optical device characterization, fiber-optic gyroscopes$^{(1)}$ , and spectrum sliced light source in wavelength division multiplexing (WDM) system$^{(2)}$ . To utilize the inherent low loss in silica optical fibers, various types of incoherent light sources are being developed. Among the light sources, the amplified spontaneous emission (ASE) from a rare earth doped fiber has benefits in temperature stability, high output power, low polarization dependence over semiconductor diodes$^{(3)}$ . Recently erbium doped fibers (EDF) have been intensively researched for ASE sources as well as optical amplifiers$^{(4)}$ . The spectrum of ASE from an EDF, however, is limited in the 1520~1560 nm range in conventional configurations. In this letter we described a new broadband ASE source which included both the conventional ASE band of Er$^{3+}$ ion, 1520nm~1560nm and ASE band from Tm$^{3+}$ ions that extends the bandwidth further. For the first time, to the best knowledge of authors, a fiber ASE source based on the energy transfer between Er$^{3+}$ and Tm$^{3+}$ ions in the range of 1460~1550 nm, has been demonstrated using a single 980nm pump laser diode. (omitted)omitted)

• 한국광학회지
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• 제7권1호
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• pp.1-8
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• 1996

렌즈의 실시간 성능축정을 위하여 MTF측정장치에 CCD를 많이 사용하고 있다. 본 연구에서는 2차원 CCD를 복사기 렌즈의 실시간 MFT측정장치에 사용했을 때 CCD에 의한 각종 MTF특성을 분석하였다. CCD로 측정한 복사기 렌즈의 MTF는 2차원 CCD의 shift register가 배열된 방향과 셔터 속도, 광신호 증폭회로의 증폭률에 따라 다른 특성을 나타내었다. 광원의 밝기에 의한 MTF 값의 변화를 줄이기 위하여 축상면 및 비축상면에서 복사조도가 균일한 광원장치를 제작하였으며 MTF 값이 측정된 표준렌즈를 사용하여 복사기 렌즈용 실시간 MTF측정장치를 교정하였다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.57-64
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• 2000

As integrated circuits become more complex, the number of I/O connections per chip grow. Conventional wire-bonding, lead-frame mounting techniques are unable to keep up. The space saved by shrinking die size is lost when the die is packaged in a huge device with hundreds of leads. The solution is bumps; gold, conductive adhesive, but most importantly solder bumps. Virtually every semiconductor manufacturer in the world is using or planning to use bump technology fur their larger and more complex devices. Several wafer-bumping processes used in the manufacture of bumped wafer. Some of the more popular techniques are evaporative, stencil or screen printing, electroplating, electrodes nickel, solder jetting, stud bumping, decal transfer, punch and die, solder injection or extrusion, tacky dot process and ball placement. This paper will discuss the process steps for bumping wafers using these techniques. Critical cleaning is a requirement for each of these processes. Key contaminants that require removal are photoresist and flux residue. Removal of these contaminants requires wet processes, which will not attack, wafer metallization or passivation. research has focused on enhanced cleaning solutions that meet this critical cleaning requirement. Process parameters defining time, temperature, solvency and impingement energy required to solvate and remove residues from bumped wafers will be presented herein.

• 마이크로전자및패키징학회지
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• 제7권1호
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• pp.51-59
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• 2000

As integrated circuits become more complex, the number of I/O connections per chip grow. Conventional wire-bonding, lead-frame mounting techniques are unable to keep up. The space saved by shrinking die size is lost when the die is packaged in a huge device with hundreds of leads. The solution is bumps; gold, conductive adhesive, but most importantly solder bumps. Virtually every semiconductor manufacturer in the world is using or planning to use bump technology for their larger and more complex devices. Several wafer-bumping processes used in the manufacture of bumped wafer. Some of the more popular techniques are evaporative, stencil or screen printing, electroplating, electroless nickel, solder jetting, stud humping, decal transfer, punch and die, solder injection or extrusion, tacky dot process and ball placement. This paper will discuss the process steps for bumping wafers using these techniques. Critical cleaning is a requirement for each of these processes. Key contaminants that require removal are photoresist and flux residue. Removal of these contaminants requires wet processes, which will not attack, wafer metallization or passivation. Research has focused on enhanced cleaning solutions that meet this critical cleaning requirement. Process parameters defining time, temperature, solvency and impingement energy required to solvate and remove residues from bumped wafers will be presented herein.

• 한국전기전자재료학회논문지
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• 제33권2호
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• pp.93-98
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• 2020

We investigated the effect of a post-annealing process using ultraviolet (UV) light on the electrical properties of solution-processed InZnO (IZO) thin-film transistors (TFTs). UV light was irradiated on IZO TFTs for different time periods of 0s, 30s, and 90s. We measured transfer and retention stability curves to evaluate the performance of the fabricated TFTs. In addition, we measured height, amplitude, and phase AFM images to analyze changes in the surface and morphology of the devices. AFM measurements were performed by setting the drive amplitude of the cantilever tip to 47.9 mV in tapping mode, then dividing the device surface into 500 nm × 500 nm. In the case of IZO TFT irradiated with UV for 30s, the electron mobility and I_on/I_off ratio were improved, the threshold voltage was reduced by approximately 2 V, and the subthreshold swing also decreased form 1.34 V/dec to 1.11 V/dec.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.47-48
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• 2015

As the power system develops rapidly into a smarter and more flexible state, so must the communication technologies that support it. Machine to machine (M2M) communication in Smart Grid environment has been discussed in European Telecommunications Standards Institute (ETSI). The power system is not easily replaceable, due to system replacement cost. The M2M gateway is required in other to improve interoperability in M2M environment. The Distributed Network Protocol 3.0 (DNP3.0) is the most important standard in the SCADA systems for the power. It has been used for device data collection/control in Substation Systems, Distribution Automation System. If the DNP3.0 data model is combined with a set of contemporary web protocols, it can result in a major shift. We selected Constrained Application Protocol (CoAP) based on RESTful as M2M protocol. It is a specialized web transfer protocol for use with constrained nodes and constrained networks. We have used the OPNET Modeler 17.1 in order to verity the SOAP versus CoAP. In this paper, we propose the CoAP-based M2M Gateway to Distribution Automation system using DNP3.0 in Smart Grid Environment.

• 한국컴퓨터산업학회논문지
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• 제3권8호
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• pp.1063-1072
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• 2002

기타는 내부 구조와 재질에 따라, 기타 음의 특성이 달라진다. 개발된 장치는 기타 내부 구조와 재질의 변동에 따른 기타 음의 분석을 컴퓨터로 처리하여 data base화 할 수 있도록 한 장치이다. 시스템의 구성은, 기타 내부 구조를 쉽게 변경할 수 있도록 한 기구부와, 다 채널의 음향 입력을 A/D 변환하여 DSP 보드에서 처리 한 후 RS232C를 통하여 PC 에 입력하는 방법으로 음량를 수집할 수 있는 입력 장치부와, 입력된 데이터를 컴퓨터에서 data base화 하여 쉽게 조회 및 분석 할 수 있도록 하는 소프트웨어로 구성되어 있다.

• 한국항행학회논문지
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• 제15권4호
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• pp.646-654
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• 2011

최근 구급차에 탑승하는 응급 구조사의 인원이 턱없이 부족하여 소방관 한 사람만이 구급차에 타고 환자를 이송하는 일이 종종 문제시 되곤 한다. 응급환자가 발생 시 신속하고 정확한 조치가 무엇보다도 필요하며 특히, 환자에게 적합한 의료기기가 있는 전문적인 병원으로 이송해야한다. 본 논문은 스마트 폰을 이용하여 병원 전 단계의 응급의료 시스템을 구현한다. 구현된 시스템은 환자 이송 중에 환자의 심박동을 실시간적으로 모니터링이나, 과거 환자의 병력 정보 등을 파악할 수 있으며, 환자가 필요로 하는 응급 병원 정보도 제공하여 병원 전 단계에서 응급 환자에게 신속하고 효율적인 처치가 가능한 환경을 제공한다.

• 한국전산유체공학회지
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• 제10권2호
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• pp.48-53
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• 2005

This work discusses the numerical analysis, the design and experimental test of the SMA actuator along with its capabilities and limitations. Convective heating and cooling using water actuate the SMA(Shape memory alloy) element of the actuator. The fuel such as propane, having a high energy density, is used as the energy source for the SMA actuator in order to increase power and energy density of the system, and thus in order to obviate the need for electrical power supplies such as batteries. The system is composed of a pump, valves, bellows, a heater(burner), control unit and a displacement amplification device. The experimental test of the SMA actuator system results in 150 MPa stress(force : 1560 N) with $3\%$ strain and 0.5 Hz. actuation frequency. The actuation frequency is compared with the prediction obtained from numerical analysis. For the designed SMA actuator system, the results of numerical analysis were utilized in determining design parameters and operating conditions.