Optimization of soaking in aqueous ammonia pretreatment of canola residues for sugar production

유하영(Yoo, Hah-Young),김성봉(Kim, Sung Bong),이상준(Lee, Sang Jun),이자현(Lee, Ja Hyun),서영준(Suh, Young Joon),김승욱(Kim, Seung Wook) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

Bioenergy production from lignocellulosic biomass and agriculture wastes have been attracted because of its sustainable and non-edible source. Especially, canola is considered as one of the best feedstock for renewable fuel production. Oil extracted canola and its agriculture residues are reuseable for bioethanol production. However, a pretreatment step is required before enzymatic hydrolysis to disrupt recalcitrant lignocellulosic matrix. To increase the sugar conversion, more efficient pretreatment process was necessary for removal of saccharification barriers such as lignin. Alkaline pretreatment makes the lignocellulose swollen through solvation and induces more porous structure for enzyme access. In our previous work, aqueous ammonia (1~20%) was utilized for alkaline reagent to increase the crystallinity of canola residues pretreatment. In this study, significant factors for efficient soaking in aqueous ammonia pretreatment on canola residues was optimized by using the response surface method (RSM). Based on the fundamental experiments, the real values of factors at the center (0) were determined as follows; 70?C of temperature, 17.5% of ammonia concentration and 18 h of reaction time in the experiment design using central composition design (CCD). A statistical model predicted that the highest removal yield of lignin was 54% at the following optimized reaction conditions: 72.68?C of temperature, 18.30% of ammonia concentration and 18.30 h of reaction time. Finally, maximum theoretical yields of soaking in aqueous ammonia pretreatment were 42.23% of glucose and 22.68% of xylose.

A New Fast Pitch Search Algorithm using Line Spectrum Frequency in the CELP Vocoder

배명진,손상목,유하영,변경진,Bae, Myung-Jin,Sohn, Sang-Mok,Yoo, Hah-Young,Byun, Kyung-Jin The Acoustical Society of Korea 1996 韓國音響學會誌 Vol.15 No.2

Code Excited Linear Prediction(CELP) vocoder exhibits good performance at data rates below 8 kbps. The major drawback of CELP type coders is a large amount of computation. In this paper, we propose a new pitch searching method that preserves the quality of the CELP vocoder reducing computational complexity. The basic idea is that grasps preliminary pitches using the first formant of speech signal and performs pitch search only about the preliminary pitches. As applying the proposed method to the CELP vocoder, we can reduce complexity by 64% in the pitch search. 부호여기된 선형예측(CELP) 음성부호화기는 4.8kbps이하의 낮은 전송 비율에서도 좋은 성능을 갖는다. CELP형 부호기의 단점은 많은 계산량을 필요로 한다는 것이다. 본 논문에서, 우리는 복잡성을 줄이면서 CELP보코더의 음질을 유지하는 새로운 피치검색법을 제안하였다. 이 방법은 CELP보코더의 포만트 필터단에서 찾은 제 1 포만트를 이용하여 예비피치를 찾고, 피치검색을 예비피치 구간에서만 수행하는 것이다. 제안한 방법을 CELP보코더에 적용하므로써, 기존의 방법에 비해 약 64%의 복잡성이 감소되었다.

젖당(Lactose)으로부터 락툴로오스(Lactulose) 생산을 위한 연구 동향

이자현 ( Ja Hyun Lee ),유하영 ( Hah Young Yoo ),정다운 ( Da Un Jung ),박찬호 ( Charn Ho Park ),송윤석 ( Yoon Seok Song ),박철환 ( Chul Hwan Park ),김승욱 ( Seung Wook Kim ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.4

락툴로오스는 식품과 제약분야에서 기능성 성분으로 알려져 있으며, 산업적으로 많이 활용되고 있어 주목을 받고 있다. 식품분야에서는 정장작용을 위한 비피더스 인자, 제약분야에서는 주로 변비, 간성뇌증, 간질환의 합병증 그리고 혈액 내 포도당(glucose)과 인슐린 수치의 유지 등을 위하여 이용되고 있다. 락툴로오스 합성은 크게 화학적, 생물학적 방법으로 분류할 수 있으며, 화학적 방법에서는 젖당(lactose)의 알칼리 이성질체화법에 의하여 합성되지만, 생성물의 분해 및 다양한 부반응에 의한 정제의 난점과 폐기물 관리 등의 문제점들을 가지고 있다. 이러한 문제점들을 해결하고자, 효소를 이용한 합성 방법이 최근 연구되고 있다. 베타-갈락토시다아제(β-galactosidase)는 젖당의 가수분해물 생산이 가능하기에 유제품 산업에서 매우 중요한 효소이며, 과당(fructose)으로 갈락토실(galactosyl) 잔기의 전달반응에 의하여 젖당으로부터 락툴로오스를 합성할 수 있다. 그러나 정제된 젖당은 매우 고가의 물질로써 락툴로오스를 합성하기에는 경제적으로 적합하지 않다. 본 총설에서는 락툴로오스를 합성하기 위한 화학적, 생물학적 공정에 대한 연구 동향을 간략하게 소개하고, 저가의 기질을 활용한 경제적인 락툴로오스 생산에 대한 연구 및 전망을 제시하고자 한다. Lactulose is well known for functional component in the food and pharmaceutical field and utilized in a wide variety of foods as a bifidus factor or functional ingredient for intestinal regulation. Lactulose synthesis can be classified into chemical and biological methods. In chemical methods, lactulose is synthesized by alkaline isomerization, but it has many disadvantages such as including product purification, lactulose degradation, side reactions and waste management. Therefore, the enzymatic synthesis methods were recently studied to solve these problems. β-galactosidase is a important enzyme in the dairy industry, because of the production of lactose-hydrolyzed products. Also, β-galactosidases can be utilized to synthesize lactulose from lactose by a trans-galactosylation reaction, using fructose as a galactosyl acceptor. However, the synthesis of lactulose from lactose is economically not suitable due to high levels of lactose price. This review summarizes the current state of lactulose production by chemical and biological processes.

Furfural production from miscanthus and utilization of miscanthus residues

김성봉(Kim, Sung Bong),유하영(Yoo, Hah-Young),이상준(Lee, Sang Jun),이자현(Lee, Ja Hyun),최한석(Choi, Han Seok),김승욱(Kim, Seung Wook) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

Furfural is a versatile derivative. It can be utilized for a building-block of furfuryl alcohol production and a component of fuels or liquid alkanes. But in bio-process, furfural is a critical compound because it inhibits cell growth and metabolism. Furfural could be converted from xylose and usually produced from biomass in which hemicellulose is abundant. In this study, furfural production from miscanthus was performed and utilization of miscanthus residue was consequently conducted. At first, hydrolysis for investigation of miscanthus composition and furfural production was performed using sulfuric acid. Previously, we optimized dilute acid pretreatment condition for miscanthus pretreatment and the condition was found to be about 15 min of reaction time, 1.5% of acid concentration and about 140?C of temperature and 60% (about 7 g/L) of xylose was solubilized from miscanthus. Using the xylose, furfural production was conducted as second step. Approximately 160{sim}200?C of temperature was accompanied with the hydrolysis for pyrolysis of biomass. When the investigated condition; 180?C of temperature, 20 min of reaction time and 2% of acid concentration was operated for furfural production, furfural productivity was reached to be 77% of theoretical maximum. After reaction, residue of miscanthus was utilized as feedstock of ethanol fermentation. Residue was well washed using water and saccharified using hydrolysis enzymes. Hydrolysate (glucose) from saccharification was utilized for the carbon source of Saccharomyces cervisiae K35.

디지탈/아날로그 겸용 이동통신 단말기를 위한 오디오/데이타 프로세서의 실시간 구현에 관한 연구

변경진,김종재,한기천,유하영,차진종,김경수,Byun, Kyung-Jin,Kim, Jong-Jae,Han, Ki-Chun,Yoo, Hah-Young,Cha, Jin-Jong,Kim, Kyung-Su 한국음향학회 1997 韓國音響學會誌 Vol.16 No.2

본 연구는 현재 디지탈 방식의 이동통신에서 사용되는 디지탈/아날로그 겸용 단말기에서 아날로그 방식을 지원하기 위한 오디오/데이타 프로세서를 ETRI DSP를 이용하여 실시간 구현하는 것에 대한 것이다. 오디오/데이타 프로세서는 단말기가 아날로그 방식으로 동작할 때 광대역 데이타 처리, 오디오신호 처리 및 demodulation, data rate conversion 기능을 수행한다. 이와같은 기능은 어셈블리 언어로 프로그램되어 디지탈 방식에서 사용되는 보코더 프로그램과 함께 ETRI DSP에 탑재되었다. 즉 하나의 하드웨어를 이용하여 디지탈 방식의 보코더와 아날로그 방식의 오디오/데이타 프로세서를 함께 구현 함으로써 하드웨어의 효율성을 극대화 하여 기존의 아날로그 전용의 단말기와의 경쟁력을 가질 수 있도록 하였다. In this paper, the implementation of audio/data processor using ETRI DSP to support analog mode in digital/analog dual mode mobile phone is presented. Audio/data processor performs the wideband data processing, audio signal processing, demodulation function, and data rate conversion when it is operated in analog mode. These functions are programmed in assembly language, and then loaded to ETRI DSP together with vocoder program for the digital mode operation. This is a very efficient implementation of the dual mode cellular phone ASIC since the vocoder for the digital mode and audio/data processor for the analog mode are programmed together in the same hardware.

GNU 컴파일러를 이용한 ES-C2340 DSP2용 C 교차 컴파일러의 개발

김승호(Kim Sung Ho),이시영(Lee Si Young),권육춘(Kwon Yoock Choon),유하영(Yoo Hah Young),한기천(Han Ki Cheon) 한국정보처리학회 1997 정보처리학회논문지 Vol.4 No.1

In this paper, we describe the implementation of the C cross-compiler for the ES-C2340 DSP2 processor by using the GNU compiler. For the rapid and efficient developing of the compiler, we use the approach that combines some parts of the language-dependent front-end of the GNU compiler and other parts like the processor-dependent back-end which is implemented newly to build the compiler. This approach has several advantages. First, as we use GNU compiler''s well-proved excellent optimization method and multi-language support capability, we can improve the efficiency and generality of the compiler. Second, as we concentrate on the developing of processor-dependent part, it shorten the compiler developing time, third, with that, we can use high-level language as logic approving tool in processor developing process. And to support the cross-compiler, we also implement a text-level pre-linker.

On A Reduction of Pitch Searching Time by Preprocessing in the CELP Vocoder

김대식,배명진,김종재,변경진,한기천,유하영,Kim, Dae-Sik,Bae, Myeong-Jin,Kim, Jong-Jae,Byun, Kyung-Jin,Han, Ki-Chun,Yoo, Hah-Young The Acoustical Society of Korea 1994 韓國音響學會誌 Vol.13 No.3

부호여기된 선형예측(CELP) 음성부호화기는 4.8 kbps 이하의 낮은 전송 비율에서도 좋은 성능을 갖는다. CELP형 부호기의 단점은 많은 계산량을 필요로 한다는 것이다. 본 논문에서, 우리는 복잡성을 줄이면서 CELP 보코더의 음질을 유지하는 새로운 피치 검색법을 제안하였다. 이것은 음성 파형의 자기상관계를 간단한 전처리관계식에 의해 사전에 파악하여 필요한 구간에 대해서만 피치검색을 수행하는 방법이다. 제안한 방법은 피치검색에서 기존의 방법에 비해 약 $77\%$의 복잡성이 감소되었다. Code Excited Linear Prediction(CELP) speech coders exhibit good performance at data rates below 4.8 kbps. This major drawback of CELP type coders is required much computation. In this paper, we propose a new pitch search method that preserves the quality of the CELP vocoder with reducing complexity. In the pitch searching, we detect the segments of high correlation by a simple preprocessing, and then carry out the pitch searching only for the segments obtained by the preprocessing. By using the proposed method, we can get approximately $77\%$ complexity reduction in the pitch search.

On a Reduction of Pitch Searching Time by Preliminary Pitch in the CELP Vocoder

김대식,배명진,김종재,변경진,한기천,유하영,Kim, Dae-Sik,Bae, Myung-Jin,Kim, Jong-Jae,Byun, Kyung-Jin,Han, Ki-Chun,Yoo, Hah-Young The Acoustical Society of Korea 1994 韓國音響學會誌 Vol.13 No.e2

Code Excited Linear Prediction(CELP) vocoder exhibits good performance at data rates below 4.8 kbps. The major drawback to CELP type coders is their large amount of computation. In this paper, we propose a new pitch search method that preserves the quality of the CELP vocoder with reduced complexity. The basic idea is to restrict the pitch searching range by estimating the preliminary pitches. Applying the proposed method to the CELP vocoder, we can get approximately 87% complexity reduction in the pitch search. 부호여기된 선형예측(CELP) 음성부호화기는 4.8 kbps 이하의 낮은 전송 비율에서도 좋은 성능을 갖는다. CELP형 부호기의 단점은 많은 계산량을 필요로 한다는 것이다. 본 논문에서, 우리는 복잡성을 줄이면서 CELP 보코더의 음질을 유지하는 새로운 피치 검색법을 제안하였다. 그 기본 개념은 음성 파형의 예비피치를 찾아내어 피치검색 범위를 제한하는 것이다. CELP 보코더에 제안한 방법을 적용하므로써, 피치검색에서 기존의 방법에 비해 약87%의 복잡성이 감소되었다.

스트레스 내성 식물 호르몬인 앱시스산의 산업적 활용 전망

이정호 ( Jeongho Lee ),김승희 ( Seunghee Kim ),유하영 ( Hah Young Yoo ) 한국화학공학회 2020 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.58 No.4

이동성이 없는 식물은 주위 환경에서 다양한 형태의 스트레스를 받게 되는데 이를 대응하기 위한 방어 기작으로 스트레스 저항성 단백질과 조절 단백질이 생성된다. 앱시스산은 이러한 신호전달 역할을 하는 호르몬 분자로 잘 알려져 있으며, 잎의 노화, 종자의 휴면 등 식물의 생리적 반응에도 관여한다. 특히 식물이 아닌 동물, 조류(algae) 등 다른 생물계에서도 다양한 기능을 수행하는 것으로 밝혀졌다. 본 총설에서는 앱시스산의 생합성 및 신호전달 과정 그리고 그 기능에 대하여 조사하였고, 농생명공학, 의생명공학, 산업생명공학을 포함한 다양한 생명공학분야에서 앱시스산을 활용한 작물량 증대, 질병 치료제 개발, 바이오에너지 생산 등 최신 응용 연구 및 산업적 활용에 대한 동향을 살펴보았다. Plants are exposed to various types of stresses in their surroundings, and stress-resistant and regulatory proteins are produced as defense mechanisms. Abscisic acid is well known for its important role in stress signals as a phytohormone and is also involved in the physiological reactions of plants such as leaf senescence and seed dormancy. In particular, it has been found to perform a variety of functions in other biological systems, such as animals and microalgae, not plants. In this review, the biosynthesis and signaling process of abscisic acid and its function were investigated and the future prospects for the industrial application of abscisic acid in various biotechnologies, including agriculture, biomedical and industrial biotechnology, have been proposed based on study of emerging applications such as increased crop yields, disease treatment development and bioenergy production.