• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.186-195
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• 2015

This study aims at modeling the rotary drying of wood chips in co-current mode and estimating the drying time of larch (Larix kaemferi) wood chip. Drying data were obtained in a lab. scale fixed bed dryer operating with an air velocity of 1 m/sec. and at hot air inlet temperatures of $100^{\circ}C$, $200^{\circ}C$, and $300^{\circ}C$. The lab. scale fixed-bed drying rates for small, medium and large size larch wood chips that had been dried from 40% wet-based moisture content (MC) to 10% MC at $200^{\circ}C$ drying temperature were 17.3 %/min., 10.2 %/min. and 5.5 %/min., respectively. It was predicted that larch large size wood chips could be dried from 40% MC to 10% MC in about 23.0, 34.6, and 44.7 minutes at $300^{\circ}C$, $200^{\circ}C$ and $150^{\circ}C$, respectively. Expected drying times for medium size chips were about 8.6, 11.2 and 13.2 minutes and those for small size chips were 4.3, 5.5 and 6.4 minutes, respectively.

• 대한금속재료학회지
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• 제50권2호
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• pp.146-151
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• 2012

The present article shows how the fracture strength of single crystal silicon chips, which are generally used as semiconductor devices, is influenced by loading rate variation during a 3-point bending test. It was found that the fracture strength of the silicon chips slightly increases up to 4% with increasing loading rate for loading rates lower than 20 mm/min. Meanwhile, the fracture strength of the chips hardly increases with increase of loading rate to levels higher than 40 mm/min. However, there was an abrupt transition in the fracture strength within a loading rate range of 20 mm/min to 40 mm/min. This work explains through microscopic examination of the fracture surface of all test chips that such a big transition is related to the deflection of crack propagation direction from the (011) [${\bar{1}}00$] system to the (111) [${\bar{2}}11$] system in a particular loading rate (i.e. from 20 mm/min to 40 mm/min).

• 한국환경농학회지
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• 제20권4호
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• pp.203-210
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• 2001

숲가꾸기사업 등의 산림사업에 의하여 발생하는 미이용 산림자원의 고부가가치로의 이용을 위하여 유효 세립 목질칩을 제조하여 목질칩의 특성, 분뇨처리 선능, 정화조 적용시험 및 제반 조건 탐색 및 제작을 시도하였다. 시판중인 일본산 삼나무칩으로 제조된 바이오클러스터는 공극율, 수분보유율, 투수계수가 우수하고, 열수추출물함량이 적고 셀룰로오스함량이 상대적으로 높게 나타났으며 해부학적 특성에서 방사단면 유연막공의 화학적 처리 흔적은 없으며 삼나무칩과 비교시 횡단면 가도관의 세포막이 얇고 공극이 상대적으로 큰 것으로 나타났다. 돈분뇨 정화용 적정 목질칩 크기는 10 (길이) ${\times}$ 5 (너비) ${\times}$ 2 (두께) mm이였으며 소나무 및 현사시외 전셀룰로오스함량이나 열수추출물함량이 바이오클러스터에 근접하였다. 처리과정에서 돈분뇨는 만재 (晩材)보다는 조재 (早材)의 세포내강에 충전되어 있으며 목질칩의 표면층에서는 세포막이 미생물 공격에 의하여 파괴된 흔적이 있었으나 장기간 사용이 가능한 것으로 추정되었다. 목질칩 종류별 돈분뇨 분해능에서 소나무 > 잣나무 > 삼나무 순으로 나타나 소나무 또는 잣나무 무처리 목질칩이 돈분뇨 분해용 정화조 사용에 적당한 것으로 판단되었다. 목질칩에 의한 돈분뇨 분해는 시간별로 일정하게 분해량을 유지 ($15{\sim}16$ g/시간/kg칩)하며 잣나무 1톤 칩 이용시 일일 돈분뇨 분해량은 390 kg (약 70두 분량)이였다. 목질칩에 의한 돈분뇨 장기처리시 40일간 처리 목질칩은 전질소함량이 안정화되었고 pH도 적정 수준이나 칼슘, 인, 칼륨, 나트륨 등이 초기 칩과 비교하여 $31{\sim}118$배 이상 축적되며, 처리칩은 흑갈색을 띄며 냄새가 없었다. 목질칩에 의한 돈분뇨 계절별 처리시 동절기에도 정화조 내부온도 $43^{\circ}C$ 이상을 유지하며 발효가 정상적으로 진행되나 분뇨의 점도 및 pH 상승으로 기포가 발생하므로 대형정화조 제작시 송풍 및 기포처리장치 필요를 확인하였다. 최적 목질칩과 돈분뇨 투입 비율은 $1:2{\sim}1:3$이며, 1:3비율이상에서 혐기화로 인한 암모니아가스 악취 발생, 시간당 3분 교반시 제일 양호한 분해능을 나타냈다.

• 전자공학회지
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• 제31권1호
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• pp.58-72
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• 2004

Smart sensors and biochip technologies have received a great deal of attention in recent years not only because of the enormous potential markets in the healthcare expenditures but more importantly because of its great impact on the quality of human life in the future. Collaborative research among BT (Bio Technologies), IT (Information Technologies) and NT (Nano Technologies) will bring us a new paradigm of the healthcare services. Examples include disease prediction based on the genetic tests, personal medicines, point-of-care analysis, rapid and sensitive infectious disease diagnostics, environmental monitoring for chemical or biological warfares, intelligent drug delivery systems etc. In this report, recent accomplishment in the research area on biosensors, DNA chips, Protein Chips and Lab-on-a-chips are reviewed.

• 한국연소학회지
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• 제4권2호
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• pp.11-22
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• 1999

Combustion characteristics of the wood chips(balsa chips) were experimentally investigated with respect to the thermal recycle system of the urban waste. The urban waste contains plastics, vegetable and wood materials. Wood was chosen as an example of the one of the component of urban dust. A small wood chip was burned in a electric furnace by the micro-electric balance. The mass reduction rate was normalized by the initial mass of test piece and the time of volatile combustion end. When the mass of the wood chips(balsa chips) was larger than 0.5g, the combustion similarity was found on the normalized mass reduction rate.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2005년도 추계학술대회지
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• pp.191-196
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• 2005

칩의 마크는 종류별로 다르고 매우 작아서 작업자가 육안 검사로 처리하기에는 매우 어려운 작업이다. 본 논문에서는 칩의 마크를 인식하여 잘못된 마크를 판별하는 마크 자동 검사 시스템에 대하여 제안한다. 불량 항목을 검사하기 위해서 템플릿 매칭 방법과 다양한 불량 판별 조건을 사용한다. 그리고 불량판별 조건은 문자 ROI 명암도, 문자 ROI 매칭, 문자 명암도, 브로컨, 브렌치로 분류된다. 제안된 방법은 마크 불량 판별에 커다란 성능향상이 보임을 일련의 실험들을 통하여 보여준다.

• 전자공학회논문지B
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• 제32B권1호
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• pp.96-102
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• 1995

This paper presents the VHSIC Hardware Description Language(VHDL) implementation of the Fixed Point Covariance Lattice(FLAT) algorithm for an Linear Predictive Coding(LPC) analysis and its related algorithms, such as the forth order high pass Infinite Impulse Response(IIR) filter, covariance matrix calculation, and Spectral Smoothing Technique(SST) in the Vector Sum Exited Linear Predictive(VSELP) speech coder that has been Selected as the standard speech coder for the North America and Japanese digital cellular. Existing Digital Signal Processor(DSP) chips used in digital cellular phones are derived from general purpose DSP chips, and thus, these DSP chips may not be optimal and effective architectures are to be designed for the above mentioned algorithms. Then we implemented the VHDL code based on the C code, Finally, we verified that VHDL results are the same as C code results for real speech data. The implemented VHDL code can be used for performing logic synthesis and for designing an LPC Application Specific Integrated Circuit(ASOC) chip and DsP chips. We first developed the C language code to investigate the correctness of algorithms and to compare C code results with VHDL code results block by block.

• 전자공학회논문지B
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• 제31B권9호
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• pp.1-9
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• 1994

This paper analyzes the faults and their mechanism of CMOS ICs using IDDQ testing technique and evalutes the reliability of the chips that fail this test. It is implemented by the three testing phases, initial test, burn-in and life test. Each testing phase includes the parametric test, functional test, IDDQ test and propagation delay test. It is shown that the short faults such as gate-oxide short, bridging can be only detected by IDDQ testing technique and the number of test patterns for this test technique is very few. After first burn-in, the IDDQ of some test chips is decreased, which is increased in conventional studies and in subsequent burn-in, the IDDQ of all test chips is stabilized. It is verified that the resistive short faults exist in the test chips and it is deteriorated with time and causes the logic fault. Also, the new testing technique which can easily detect the rsistive short fault is proposed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.633-639
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• 2010

Cold area in korea, railway roadbed and gravel ballast was occurred frost-heaving. So during winter, track was rising and during thaw, track was sinking. In order to prevent the damage of frost-heaving, we have applied a few countermeasures which are circumfusion of calcium chloride and replacement of gravel ballast method. This countermeasures effect is feeble, not continuous and not eco-friendly. This study suggested that we use wasted tire-chips in frost-heaving area and considered appropriate new method to maintenance. This method was named "A Method of Wasted Tire-Chips Post". To prove effect of this method, we have tested in laboratory and field. The result of frost-heaving-ratio field test was decreased frost-heaving-ratio about 50% using "A Method of Wasted Tire-Chips Post".

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.139-146
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• 1999

Combustion Characteristics of the wood chips(balsa chips) were experimental studied as fundamental investigation of the thermal recycle system of the urban dust. The urban dust contains plastics vegetable and lot of wood material. Then, a wood was chosen as an example of the component of urban dust. A small wood chip was burned in a electric furnace and mass reduction rate during volatile and combustion states were recorded by the micro-electric balance and the combustion flame shape took a photograph by video camera at the mass of wood chips and ambient temperature in the furance. Ignition delay took the minimum value when the mass of the test chip was 0.3g. When a mass of the test chip was smaller then 0.001g, combustion with flame did not burnt.