• Journal of Life Science
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• v.24 no.12
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• pp.1325-1329
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• 2014

Gugija (Lycii chinese Miller) is traditionally consumed as a Chinese medicinal material in food, tea, or alcoholic beverages. Gugija has beneficial healthy components, but it produces an off-flavor during storage. This study compared the flavor components of fresh-dried Gugija and stale-dried Gugija. The flavor compounds in one fresh sample (sample 1) and one stale sample (sample 2) were extracted by the simultaneous distillation and extraction method. The concentrated aroma extracts were analyzed and identified by gas chromatography-mass spectrometry. Forty-five compounds, including 17 aldehydes, 8 alcohols, 6 terpene compounds, 4 esters, 3 ketones, and 3 pyrazines, were isolated in sample 1. Thirty-four compounds, including 12 aldehydes, 3 alcohols, 5 terpene compounds, 2 esters, 3 ketones, 3 pyrazines, and 1 acid, were isolated in sample 2. The main aroma components of sample 1 were 2-methyl butanal, 2-methyl propanol having sweet odor, and hexanal, (Z)-3-hexenol having grass odor, and phenyl acetaldehyde, benzyl alcohol having floral odor, and alkyl pyrazines having nutty odor. These compounds were decreased in sample 2, and several compounds containing isovaleric acid, which has a disagreeable, rancid-cheese odor were found newley.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1937-1941
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• 2007

During a process of a nanoimprint for manufacturing LCD, a small temperature variation on the LCD glass can cause thermal stress and generate unexpected displacement. To avoid this trouble, a precision temperature control unit using thermoelectric modules is appropriate for nanoimprint processes. The unit consists of an air control system, a cooling water control system, and a power control system. The air control system includes a thermoelectric module, thermocouples measuring temperatures of air and a duct-stale fin, and two air fans. The heat generated by the thermoelectric module is absorbed by the cooling water control system. The power control system catches the temperature of the thermoelectric module, and a PID controller with SCR controls the input power of the thermoelectric module. Temperature control performance is evaluated by experiment and simulation. The temperature control unit is able to control the exit temperature about ${\pm}2^{\circ}C$ from the incoming fluid temperature, and the error range is ${\pm}0.1^{\circ}C$. However, the control time is approximately 30minute, which needs further study of active control

• Industrial Engineering and Management Systems
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• v.7 no.3
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• pp.257-265
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• 2008

This paper deals with the joint decisions on pricing and ordering for a monopolistic retailer who sells perishable goods with a fixed lifetime or demand period. The newsvendor-typed problem is formulated as a two-period inventory system where the first period represents the inventory of fresh or new-arrival items and the second period represents the inventory of items that are older but still usable. Demand may be for either fresh items or for somewhat older items that exhibit physical decay or deterioration. The retailer is allowed to adjust the selling price of the deteriorated items in the second period, which stimulates demand and reduces excess season-end or stale inventory. This paper develops a stochastic dynamic programming model that solves the problem of preseason decisions on ordering-pricing and a within-season decision on markdown pricing. We also develop a fixed-price model as a benchmark against the dual-price dynamic model. To illustrate the effect of the dual-price policy on expected profit, we conduct a comparative study between the two models. Extension to a generalized multi-period model is also discussed.

• Communications of the Korean Mathematical Society
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• v.9 no.4
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• pp.905-915
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• 1994

Let $M_g$ be the moduli space of isomorphism classes of genus g smooth curves. It is a quasi-projective variety of dimension 3g - 3, when $g > 2$. It is known that a complete subvariety of $M_g$ has dimension $< g-1 [D]$. In general it is not known whether this bound is rigid. For example, it is not known whether $M_4$ has a complete surface in it. But one knows that there is a complete curve through any given finite points [H]. Recently, an explicit example of a complete curve in moduli space is given in [G-H]. In [G-H] they constructed a complete curve of $M_3$ as an intersection of five hypersurfaces of the Satake compactification of $M_3$. One way to get a complete curve of $M_3$ is to find a complete one dimensional family $p : X \to B$ of plane quartics which gives a nontrivial morphism from the base space B to the moduli space $M_3$. This is because every non-hyperelliptic smooth curve of genus three can be realized as a nonsingular plane quartic and vice versa. This paper has come out from the effort to find such a complete family of plane quartics. Since nonsingular quartics form an affine space some fibers of p must be singular ones. In this paper, due to the semistable reduction theorem [M], we search singular plane quartics which can occur as singular fibers of the family above. We first list all distinct plane quartics in terms of singularities.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.345-351
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• 2004

We investigated the anaerobic ammonium oxidation (anammox) reaction in a lab-stale upflow anaerobic sludge blanket (UASB) reactor. Our aim was to detect and enrich the organisms responsible for the anammox reaction using a synthetic medium that contained low concentrations of substrates (ammonium and nitrite). The reactor was inoculated with granular sludge collected from a full-scale anaerobic digestor used for treating brewery wastewater The experiment was performed during 260 days under conditions of constant ammonium concentration ($50\;mg\;NH_4^+-N/L$) and different nitrite concentrations ($50{\~}150\;mg\;NO_2-N/L$). After 200 days, anammox activity was observed in the system. The microorganisms involved in this anammox reaction were identified as Candidatus B. Anammoxidans and K. Stuttgartiensis using fluorescence in situ hybridization (FISH ) method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.671-672
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• 2011

Time to digital converter is designed. To obtain the digital signal from time information the analog delay element is used. Because the analog delay element shows more stable characteristics compared to the digital delay element in view point of process variation. The designed circuit has temperature stale characteristics when the range of operating temperature is from $-20^{\circ}C$ to $70^{\circ}C$. The circuit is simulated and confirmed by HSPICE.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.561-568
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• 2000

본 연구의 목적은 Piezocone 관입시험을 이용한 연약지반의 OCR 평가에 있어 기존의 여러 가지 해석방법들과 최근에 새롭게 제안된 방법들을 실내 모형토조에서 실측된 피에조콘 관입 실험치에 적용하여 각 해석방법들의 차이와 장단점들을 비교 분석하는데 있다. 본 연구의 연구실험방법으로는, Piezocone 관입을 위한 연약 모형지반 조성을 위하여 초대형 Slurry Consolidometer에 Free Stress 상태의 Slurry를 45일간 압밀시킨후 Automatic Computer Control Calibration Chamber (LSU/CALCHAS; Louisiana Slate University Calibration Chamber System)에 옮긴후 다시한번 압밀시키는 Two-Stage Consolidation Method를 사용하였다. 모형지반은 여러 가지 Boundary Condition들과 Stress Condition 그리고 Stress History등을 달리하여 총 5개의 지반을 조성하였다. 관입시험은 총 25개의 Piezocone 관입이 수행되어졌고, 그중 4개는 Standard 10 cm2 Piezocone이고, 나머지 21개는 Miniature Piezocone이 사용되었다. Piezocone 실험치들에 대한 여러 가지 OCR 해석방법 적용결과, Schmertmann방법은 5개 모형지반 모두에서 과다한 OCR평가를 보였으며, $B_{q}$ 방법은 일부모형지반에서 음의 OCR값으로 계산되어졌다. 그러나, Critical-Stale Soil Mechanics 와 Cavity Expansion 이론에 근거하여 Mayne(1991), Kurup(1993), Tumay et al (1995) 들이 제안한 OCR 평가방법들은 실험치와 잘맞는 경향을 보여주었다. 이와같은 이론 모델값들의 차이는 응력조건(Stress Condition)과 경계조건(Boundary Condition)들에 대한 각 해석방법들의 고려정도에 따른 결과로 판단된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.115-118
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• 2004

The phase transition between amorphous and crystalline states in chalcogenide semiconductor films can controlled by electric pulses or pulsed laser beam; hence some chalcogenide semoconductor films can be applied to electrically write/erase nonvolatile memory devices, where the low conductive amorphous state and the high conductive crystalline stale are assigned to binary states. AST(AsSbTe) used to phase change material by applying electical pulses. Thickness of AST chalcogenide thin film have about 100nm. Electrodes are made of ITO and Al. $T_c$(Crystallization temperature) of AST system is lower than that of the GST(GeSbTe) system, so that the current pulse width of crystallization process can be decreased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.5
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• pp.403-412
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• 1991

This paper proposes a type of self organizing neural network which recognizes arbitrary symbols as well as numerical or alphabetic characters. The proposed algorithm autonomically organizes and classifies similar patterns on the basis of the distribution types of characteristics in the input images. Thus it can be appliced for the recognition of arbitrary images when it is difficult to establish a learning rule. It performs a stale recognition process with in the limit of the memory capacity. The cheme was applied and tested to 50 different image patterns with increased noise level up to 44%(SNR 2dB). The implementation results demonstrate that the proposed algorithm successfully recognizes the image patterns changed due to the various noise levels and thus proves excellent antinoise characteristics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.8
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• pp.1388-1403
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• 2011

A vehicular ad-hoc network (VANET) consists of vehicles that form a network without any additional infrastructure, thus allowing the vehicles to communicate with each other. VANETs have unique characteristics, including high node mobility and rapidly changing network topology. Because of these characteristics, routing algorithms based on greedy forwarding such as greedy perimeter stateless routing (GPSR) are known to be very suitable for a VANET. However, greedy forwarding just selects the node nearest to the destination node as a relay node within its transmission range. This increases the possibility of a local maximum and link loss because of the high mobility of vehicles and the road characteristics in urban areas. Therefore, this paper proposes a reliability-improving position-based routing (RIPR) algorithm to solve those problems. The RIPR algorithm predicts the positions, velocities, and moving directions of vehicles after receiving beacon messages, and estimates information about road characteristics to select the relay node. Thus, it can reduce the possibility of getting a local maximum and link breakage. Simulation results using ns-2 revealed that the proposed routing protocol performs much better than the existing routing protocols based on greedy forwarding.