• 제목/요약/키워드: dSOI

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음식물의 악취 황화합물 발생특성 조사: 계란, 우유, 고기통조림, 딸기에 대한 사례 연구 (Emission Characteristics of Odorous Sulfur Gases from Food Types: A Case Study on Boiled Egg, Milk, Canned Meat, and Strawberry)

  • 김보원;안정현;김기현;조상희
    • 한국대기환경학회지
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    • 제29권5호
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    • pp.615-624
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    • 2013
  • In this study, the emission patterns of reduced sulfur compounds (RSC) were investigated using four different types of food samples (boiled egg, milk, canned meat and strawberry) between fresh and decaying stages. To this end, the concentrations of RSCs were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. Four sulfur compounds ($H_2S$, $CH_3SH$, DMS and DMDS) were selected as target compounds along with two reference compounds ($CS_2$ and $SO_2$). Their concentrations were quantified using GC-PFPD equipped with thermal desorption (TD) system. The boiled egg showed the highest concentration of $H_2S$ (3,655 ppb) at D-1, while $CH_3SH$ reached its maximum value of 64.4~78.5 ppb after 3 days. In milk samples, concentration of $CH_3SH$, DMS, and DMDS went up to 487, 16.3, and 578 ppb, respectively with the progress of decay (D-9). In case of canned meat, concentration of $H_2S$ and $CH_3SH$ peaked in the beginning (D-0) such as 345 and 66.6 ppb. In case of strawberry, $CH_3SH$ and DMDS showed the maximum concentrations 135 and 50.5 ppb at D-1, respectively. The olfactometry dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test showed similar patterns when sum of odor intensity (SOI) was derived via conversion of odorant concentration data. The results of this study confirm that the time of strong RSC emissions is distinguished for each food type between fresh (e.g., strawberries) and decaying conditions (e.g., milk).

A Highly Efficient Dual-Mode 3G/4G Linear CMOS Stacked-FET Power Amplifier Using Active-Bypass

  • Kim, Unha;Kim, Yong-Gwan;Woo, Jung-Lin;Park, Sunghwan;Kwon, Youngwoo
    • Journal of electromagnetic engineering and science
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    • 제14권4호
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    • pp.393-398
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    • 2014
  • A highly efficient dual-mode linear CMOS stacked-FET power amplifier (PA) is implemented for 3G UMTS and 4G LTE handset applications. High efficiency is achieved at a backed-off output power ($P_{out}$) below 12 dBm by employing an active-bypass amplifier, which consumes very low quiescent current and has high load-impedance. The output paths between high- and low-power modes of the PA are effectively isolated by using a bypass switch, thus no RF performance degradation occurs at high-power mode operation. The fabricated 900 MHz CMOS PA using a silicon-on-insulator (SOI) CMOS process operates with an idle current of 5.5 mA and shows power-added efficiency (PAE) of 20.5%/43.5% at $P_{out}$ = 12.4 / 28.2 dBm while maintaining an adjacent channel leakage ratio (ACLR) better than -39 dBc, using the 3GPP uplink W-CDMA signal. The PA also exhibits PAE of 35.1% and $ACLR_{E-UTRA}$ of -33 dBc at $P_{out}$ = 26.5 dBm, using the 20 MHz bandwidth 16-QAM LTE signal.

3차원 LIGA 미세구조물 제작을 위한 마이크로 액추에이터 내장형 X-선 마스크 (Deep X-ray Mask with Integrated Micro-Actuator for 3D Microfabrication via LIGA Process)

  • 이광철;이승섭
    • 대한기계학회논문집A
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    • 제26권10호
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    • pp.2187-2193
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    • 2002
  • We present a novel method for 3D microfabrication with LIGA process that utilizes a deep X-ray mask in which a micro-actuator is integrated. The integrated micro-actuator oscillates the X-ray absorber, which is formed on the shuttle mass of the micro-actuator, during X-ray exposures to modify the absorbed dose profile in X-ray resist, typically PMMA. 3D PMMA microstructures according to the modulated dose contour are revealed after GG development. An X-ray mask with integrated comb drive actuator is fabricated using deep reactive ion etching, absorber electroplating, and bulk micromachining with silicon-on-insulator (SOI) wafer. 1mm $\times$ 1 mm, 20 $\mu$m thick silicon shuttle mass as a mask blank is supported by four 1 mm long suspension beams and is driven by the comb electrodes. A 10 $\mu$m thick, 50 $\mu$m line and spaced gold absorber pattern is electroplated on the shuttle mass before the release step. The fundamental frequency and amplitude are around 3.6 kHz and 20 $\mu$m, respectively, for a do bias of 100 V and an ac bias of 20 $V_{p-p}$ (peak-peak). Fabricated PMMA microstructure shows 15.4 $\mu$m deep, S-shaped cross section in the case of 1.6 kJ $cm^{-3}$ surface dose and GG development at 35$^{\circ}C$ for 40 minutes.

키르케고르: 윤리적 실존의 양상과 사랑의 윤리학 (Kierkegaard: l'aspect de l'existence éthique et l'éthique de l'amour)

  • 이명곤
    • 철학연구
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    • 제129권
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    • pp.167-191
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    • 2014
  • 키르케고르에게 있어서 자연적인 인간의 조건은 비극적인 것이다. 진정한 자신의 존재에 대해 무지한 것도, 자각하는 것도 그리고 부정하는 것도 모두 절망을 야기하기 때문이다. 나아가 죽는 순간까지 인간은 자신의 행복을 확신할 수가 없기 때문이다. 그래서 그의 윤리학은 본질적으로 '행복론'에 기초한 것이 아니다. 모든 인간은 어느 정도 자신의 참된 존재와 멀리 떨어져 살아가며, 윤리적 지평에서의 삶은 자신의 참된 존재로 향해 나아가는 삶으로 나타나고 있다. 이는 감각적이고 직접적인 삶을 의미하는 심미적인 삶으로부터 벗어나 '내면적인 자신'을 형성하는 것으로 나타나고 또한 내적인 자신과 외적인 자신의 일치를 추구하는 삶으로 나타나고 있다. 죄란 참된 자기존재로부터의 이탈을 의미하며, 이것이 모든 악의 근원처럼 고려되고 있다. 자기존재의 완전한 획득은 곧 단독자로서 절대자 앞에 나서며, 절대자와 일치를 가지는 것을 말하는 것으로 모든 인간은 어느 정도 죄를 지니고 살 수 밖에 없다. 따라서 윤리적 실존의 양상은 끝임 없이 자신을 초월하는 역동적인 삶으로 나타나고 있다. 인간의 현존재에 대한 분석이 매우 비극적인 것과는 대조적으로 이 윤리적 삶의 근본 덕목은 매우 '낙관적인 것'인데 그것은 곧 사랑이다. 이 사랑은 모든 윤리적인 덕목들을 넘어서는 탁월한 것이며, 사실상 키르케고르에게 있어서 비록 구원이 믿음을 통해서 주어지지만, 이 사랑의 원리는 구원과 행복에로 인도하는 유일한 덕목이기도 하다. 그렇기 때문에 그의 윤리학은 본질적으로 '사랑의 윤리학'으로 나타나며, 이 사랑의 원리와 국면들에 대한 탐구는 '윤리학'의 유일한 과제처럼 남아 있는 것이다.

우리 성명(姓名)의 생성 발달에 대하여 (The Origin and Development of Korean Names)

  • 도수희
    • 인문언어
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    • 제1권1호
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    • pp.255-274
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    • 2001
  • This paper examines the history of Korean names, focusing on the structural characteristics and the literal meanings of those for kings and ordinary people. Roughly speaking, the Korean surname system traces its source to China. Historical records show that the Chinese were already using their family names around 1000 B.C. After a millennium or so, the Korean began to follow suit. Initially, however, surnames were in regular use among kings and their kin only: it was not until the late Shilla dynasty, around A.D. 800, that the commoners began to have Heir surnames. And yet, surnames still tended to be limited to men of noble birth, until around A.D. 1000. Though the Korean surname system may be said to have its origin in Chinese, there are no lack of native surnames that have as long a history, e.g., Hae, Bak, Sok, Sol, Ul, and Ol. Typical surnames of Chinese origin that are found during the late Shilla dynasty, around A.D. 900, include Jang (as in Jang Bogo) and Choi (as in Choi Chiwon). Unlike those of Chinese origin, typical Korean names during the age of Three Nations tended to allude to nature or natural phenomena, as can be witnessed in Bit 'light,' Balgum 'bright,' Nuri 'world,' and Soidori where soi means 'steel' and dol 'stone,' Other surnames abound that have to do with river, stream, field, prairie, and so on. King Muryong's original name was Sama, a variant of som 'island,' indicating where he was born. A person skilled in archery was called Jumong or Hwalbo. Baembo was so called because he 'crawls like a snake, baem,' In these last two examples, bo, as well as its variant bu, functions as a suffix, and is also found in Cochilbu, Isabu, Babo, Nolbu, Hungbu, etc. The tradition of using this kind of native Korean names has gradually disappeared, giving place to the names of Chinese style-although very recently we see an on-going movement toward using native names.

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RELATIONSHIPS BETWEEN ENSO AND DROUGHTS IN KOREA AND THE CONTINENTAL U.S.

  • Lee, Dong-Ryu;Jose D. Salas
    • Water Engineering Research
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    • 제2권2호
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    • pp.139-148
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    • 2001
  • The teleconnections between El Nino/Southern Oscillation (ENSO) and droughts in Korea and the continental United States(U.S.) are investigated using cross analysis. For this purpose, monthly ENSO data and Palmer Drought Severity Index (PDSI) for Korea and for seven states in the U.S. are used. This study shows that there are significant statistical associations between ENSO indices and PDSI for Korea; however, the associations are very weak. It is found that dry conditions in Korea are positively correlated with El Nino, while wet conditions with La Nina. SOI, SSt in the Nino 4 and Ship track 6 regions among ENSO indices are more strongly correlated with PDSI than the other ENSO indices when using the original standardized data, but the SST Nino 3, SST Nino 4, and Darwin SSP exhibit abetter correlations with PDSI when using filtered data to be removed autocorrelation components of the original standardized data. The response time lag for maximum correlation between ENSO indices and PDSI appears to be affected by filtering the data. This is expecially true for Korea than for state analyzed in U.S. In addition, it is found that the PDSI in the continental U.S. is more strongly correlated wiht ENSO than in Korea. Furthermore, in analyzing the El Nino and La Nina aggregate composite data, it is found that the dry anomalies in Korea occur from the year following El Nino to about tow years after while the wet anomalies occur from La Nina year for a period of about two years.

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대칭형 이중 게이트 MOSFET에 대한 문턱전압 연구 (A Study of the Threshold Voltage of a Symmetric Double Gate Type MOSFET)

  • 이정일;신진섭
    • 한국인터넷방송통신학회논문지
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    • 제10권6호
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    • pp.243-249
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    • 2010
  • 본 논문에서는 대칭형 이중 게이트 MOSFET의 회로해석에 대한 등가모델을 제시하고자 해석적 모델을 연구하였다. 본 연구의 해석적 모델에 사용된 방법은 2차원 포아송 방정식의 해를 가정하여 표면 전위 관계식을 유도하여 실리콘 몸체 내의 전위분포를 풀어 드레인 전압 변화에 대한 문턱전압 관계식을 도출하였다. 단채널 및 장채널 실리콘 채널에서 모두 해석이 가능한 해석적 모델을 적용 가능하도록 하기 위해 MOSFET의 채널 길이에 따른 제한된 지수함수를 적용함으로써 수백 나노미터까지 해석이 가능한 대칭형 이중 게이트 MOSFET 해석적 모델을 연구하였다.

파일럿 분사시기에 따른 DME 부분 예혼합 압축착화 엔진의 연소 및 배기특성에 관한 연구 (An Investigation about Combustion and Emission Characteristics for Pilot Injection Timing on Partially Premixed Charge Combustion Ignition Engine Fueled with DME)

  • 정재훈;임옥택;표영덕;이영재
    • 한국자동차공학회논문집
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    • 제21권3호
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    • pp.43-49
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    • 2013
  • This work investigated the effects of engine speed and injection timing on combustion and emissions characteristics in a partially premixed charge compression ignition (pPCCI) engine fueled with DME. pPCCI engine especially has potential to achieve more homogeneous mixture in the cylinder, which results in lower NOx and smoke emission. In this study single cylinder engine was equipped with common rail and injection pressure is 700 bar. Total injected fuel mass is 64.5 $mm^3$ per cycle. The amount of pilot injection of the entire injection 12.5% is tested. Results show that NOx emission is decreased while IMEP is increased as the retard of injection timing. Besides, NOx emissions are slightly rised as well as IMEP is increased with the increase of engine speed.

트랩 주입의 구조적 설계에 따른 LIGBT의 전기적 특성 개선에 관한 연구 (A Study on the Design of the LIGBT Structure with Trap Injection for Improved Electrical Characteristics)

  • 추교혁;강이구;이정훈;성만영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.932-934
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    • 1999
  • In this paper, the new IGBT structures with trap injection are proposed to improve switching characteristics of the conventional SOI LIGBT. The simulations are used in order to investigate the effects of the position, width and concentration of trap injection region using 2D device simulator MEDICI. And, their electrical characteristics are analyze and the optimum design parameters are extracted. As a result of simulation, the turn off time for the proposed LIGBT model A by the trap injection is $0.78{\mu}s$. And, the latch up voltage is 3.4V and forward blocking voltage is 168V which are superior to that of conventional structure. In addition, the proposed model is achieved more efficient in switching time and process effort. Therefore, It is shown that the trap injection is very effective to reduce the turn off time with a little increasing of on-state voltage drop if its design and process parameters are optimized.

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직접분사식 압축착화엔진에서 Pilot분사에 따른 Diesel-DME 혼합연료의 연소 및 배기특성에 관한 연구 (A Study on Combustion and Emission Characteristics of Diesel-DME Blended Fuels Using Pilot Injection in DICI Engine)

  • 정재훈;임옥택
    • 한국자동차공학회논문집
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    • 제22권4호
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    • pp.55-64
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    • 2014
  • This work was investigated on pilot injection strategy of blended fuels(Diesel-DME) for combustion and emissions in a single cylinder direct injection compression ignition engine. Diesel and DME were blended by the method of weight ratio. Weight ratios for diesel and DME were 95:05 and 90:10 respectively. dSOI between main and pilot injection timing was varied. A total amount of injected fuels(single injection) was adjusted to obtain the fixed BMEP as 4.2 bar in order to compare with the fuel conditions. Also, the amount of pilot injection fuel was varied by 5%, 10% and 20% of total injection fuel. The engine was equipped with common rail and injection pressure is 700 bar at 1200 rpm. As a result, when mixing ratio increase, indicated thermal efficiency was increased in comparison with DD 100 and CO, THC and smoke were lower than DD 100. The influence of reducing NOx by pilot injection was more effective than DD 100. When pilot injection quantity increase, abrupt increase of NOx was occured at pilot injection quantity of 20%.