• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1807-1824
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• 2015

As the technologies advance, mobile peer-to-peer (MP2P) networks or systems become one of the major ways to share resources and information. On such a system, the information retrieval (IR), including the development of scalable infrastructures for indexing, becomes more complicated due to a huge increase on the amount of information and rapid information change. To keep the systems on MP2P networks more reliable and consistent, the index structures need to be updated frequently. For a semantic IR system, the index structure is even more complicated than a classic IR system and generally has higher update cost. The most well-known indexing technique used in semantic IR systems is Latent Semantic Indexing (LSI), of which the index structure is generated by singular value decomposition (SVD). Although LSI performs well, updating the index structure is not easy and time consuming. In an MP2P environment, which is fully distributed and dynamic, the update becomes more challenging. In this work, we consider how to update the sematic index generated by LSI and keep the index consistent in the whole MP2P network. The proposed Concept Space Update (CSU) protocol, based on distributed 2-Phase locking strategy, can effectively achieve the objectives in terms of two measurements: coverage speed and update cost. Using the proposed effective synchronization mechanism with the efficient updates on the SVD, re-computing the whole index on the P2P overlay can be avoided and the consistency can be achieved. Simulated experiments are also performed to validate our analysis on the proposed CSU protocol. The experimental results indicate that CSU is effective on updating the concept space with LSI/SVD index structure in MP2P semantic IR systems.

• 한국축산식품학회지
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• 제36권2호
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• pp.194-197
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• 2016

The alkaline phosphatase (ALP) assay is a rapid and convenient method for verifying milk pasteurization. Since colorimetric ALP assays rely on subjective visual assessments, their results are especially unreliable near the detection limits. In this study, we attempted to establish quantitative criteria for residual ALP in milk by using a more objective method based on spectrophotometric measurements. Raw milk was heat-treated for 0, 10, 20, 30, and 40 min and then subjected to ALP assays. The quantitative criteria for residual ALP in the milk was determined as 2 μg phenol/mL of milk, which is just above the ALP value of milk samples heat-treated for 30 min. These newly proposed methodology and criteria could facilitate the microbiological quality control of milk.

• 멤브레인
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• 제26권2호
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• pp.141-145
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• 2016

고분자전해질막은 전극 이외에 전기 화학 연료전지의 성능을 결정하는 중요한 요소이다. 고분자전해질막은 가스나 양성자 등의 작은 분자를 선택적으로 수송해야 한다. 고분자전해질막을 투과한 가스는 급속히 전기 화학적 환원을 발생시켜 음극 촉매의 열화를 유발하기 때문에 수소 장벽으로 작동해야 하며 가능한 한 빨리 양성자를 이동시켜야 한다. 지금까지 고분자전해질막의 수소 기체 투과도를 측정하는데 한정된 방법(예 : Constant volume/variable pressure (Time-lag)법)을 사용했다. 그러나 측정의 대부분은 고분자전해질막은 건조된 진공 하에서 이루어진다. 그렇지 않으면 얻어진 수소 투과도는 측정 오차가 커지는 원인이 되기 쉽다. 이 연구에서는 일반적으로 고분자전해질막으로 사용되는 Nafion212의 수소 가스 투과 특성을 온도와 습도가 동시에 제어되는 in-situ 측정 시스템을 이용하여 평가하였다.

• 한국식품과학회지
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• 제29권3호
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• pp.464-469
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• 1997

미강 식이섬유 추출물이 밀가루의 호화 및 노화에 미치는 영향을 조사하기 위하여 여러방법으로 열처리한 미강 식이섬유 추출물을 첨가하여 호화 및 노화현상을 RVA와 DSC로 측정하여 조사하였다. 그결과 미강 식이섬유 추출물 첨가는 대조구에 비해 호화온도, 최고점도 및 최종점도를 증가시켰다. 미강 식이섬유 추출물을 첨가한 시료들을 DSC로 측정했을 때 To, Tp 및 ${\triangle}H$값들은 탈지미강 식이섬유 추출물을 첨가한 시료에 영향을 받지 않았다. 노화시 나타난 endothermic peak는 호화시보다 약 $15{\sim}20^{\circ}C$ 낮은 온도에서 폭이 넓은 형태로 나타났으며, 저장기간이 길어질수록 뚜렷한 endothermic peak를 보였다. 미강 식이섬유 추출물을 첨가한 시료들은 노화지연 효과를 보였으며, 5%와 10% 첨가시료들 사이에는 큰 차이가 없었다.

• 한국인터넷방송통신학회논문지
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• 제18권4호
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• pp.143-147
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• 2018

수위는 하수장, 정수장, 하천, 댐, 공장의 저장탱크 등 다양한 분야에서 측정된다. 수위측정을 위한 초음파 기기가 판매중이나 산업용으로 실험에서 사용하기는 가격이 너무 비싸다. 전자 기술의 급속한 진보로 인해 다양한 종류의 측정, 모니터링 및 제어 기능이 저렴하게 구축하는 것이 가능해졌다. 저렴한 가격으로 초음파 수위 측정시스템을 만들기 위하여 본 연구가 시작되었다. 실험용으로 사용하기 위하여 아두이노, 초음파 센서 및 온도 센서로 시스템을 구성하였다. 초음파 센서는 센서에서 수위 표면까지의 시간을 측정한다. 온도 센서는 대기 온도를 측정하며 온도 변화로 인한 소리의 속도를 보정하여 초음파 거리 측정의 정확성을 높인다. 아두이노는 측정 전반을 관리하고 수위를 계산한다. 시스템의 모든 구성 요소는 장치거치대에 조립되었다. 제안된 시스템을 가지고 실험한 결과 수위가 실측치와 매우 가까웠다. 이 시스템은 또한 저렴하며 설치 및 유지하기가 쉬워 실험용으로 적절하다.

• 대한치과보철학회지
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• 제33권1호
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• pp.48-74
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• 1995

Since heat curing acrylic resins undergo unavoidable dimensional changes following polymerization, adaptation can be altered. Until recently, although numerous studies on the dimensional changes of denture base were based on a microscopic technic that measures the relative displacement of a limited reference points on the denture base, but there have been few studies on the distortions of resins using holographic interferometry. Purpose of this study was to determine and compare the dimensional changes and fringe patterns of 4 heat curing acrylic resins, and observe the distortions of acrylic resin denture base by temperature change with the aid of the holographic interferometry. Holographic interferograms were taken on the resin specimens and acrylic resin denture base with the 10mW He-Ne laser and double exposure method. Comparison and analysis of fringe pattern on the recorded object surface was performed. The following results were obtained. 1. The dimensional changes for the high impact resin Lucitone 199 were statistically the greatest of all resins, and the rapid heat curing resin Premium super 20 were the least. 2. The most polymerization shrinkage of all materials occured in initial period of measurements, at this time the difference of polymerization shrinkage properties between resins was founded. 3. The stress distribution of specimens was seen by various type of fringe pattern which had directionality. 4. The polymerization shrinkage of resins was greatly influenced by temperature change. 5. The partial deformations of resin denture base were observed in 70 C and 90 C water.

• Membrane and Water Treatment
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• 제9권4호
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• pp.279-284
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• 2018

Membrane biofouling is a critical operational problem that hinders the rapid commercialization of MBRs. Quorum quenching (QQ) has been investigated widely to control membrane biofouling and is accepted as a promising anti-fouling strategy. Various QQ strategies based on bacterial and enzymatic agents have been identified and applied successfully. Whereas, this study aimed to compare indigenously isolated QQ strain i.e., Enterobacter cloaca with well reported Rhodococcus sp. BH4. Both bacterial species were immobilized in polymeric beads and introduced to two different MBRs keeping the overall beads to volume ratio as 1%. Efficiencies of these strains were monitored in terms of prolonging the membrane filtration cycle of MBR, release of extra-cellular polymeric substances, membrane resistivity measurements and mineralization of signal molecules and permeate quality. Indigenous strain (Enterobacter cloaca) was added to $QQ-MBR_E$ while Rhodococcus sp. BH4 was introduced to $QQ-MBR_R$. QQ bacterial embedded beads showed enhanced filtration cycles up to 1.4 and 2.3 times for $QQ-MBR_E$ and $QQ-MBR_R$ respectively as compared to control MBR (C-MBR). Soluble EPS concentration of 52 mg/L was observed in C-MBR while significantly lower EPS concentration of 20 and 10 mg/L was witnessed in $QQ-MBR_E$ and $QQ-MBR_R$, respectively. Therefore, substantial reduction in biofouling showed the effectiveness of indigenous strain.

• 대한본초학회지
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• 제23권3호
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• pp.27-32
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• 2008

Objectives : In this paper, we describe that $^1H-NMR$ spectroscopy may be superior to the conventional HPLC for the quantitative analysis of hesperidin from Citrus unshiu. Methods : $^1H-NMR$ spectra (400 MHz) were recorded in $DMSO-d_6$ using a Varian UNITY Inova AS 400 FT NMR spectrometer. One hundred milligram of powdered Citrus unshiu was weighed out and mixed with 1 ml of $DMSO-d_6$ with sonication for 30 min (room temperature). The extracts were filtrated through a 0.45 ${\mu}m$ PVDF filter and 0.5 ml of filtrated extract used for quantitative $^1H-NMR$ measurement (added 1 mg of dimethyl terephthalate as internal standard). The quantity of hesperidin was calculated by the ratio of the intensity of the compound to the known amount of internal standard. For HPLC analysis, the half gram of plant material was extracted with 60 ml of MeOH for 2 hours. The extracts were made 100 ml volume and analyzed by a Waters HPLC system using a YMC ODS column. The total flow rate was 1.0 ml/min with a sample volume 10 ${\mu}l$ and UV detection at 280nm. Results : The contents of hesperidin in Citrus unshiu was determined $5.33{\pm}0.06$% in the quantitative $^1H-NMR$ method and $5.15{\pm}0.12%$ in HPLC method. Using the quantitative $^1H-NMR$ the contents of hesperidin can be determined in much shorter time than the conventional HPLC measurements. Conclusions : From those results, the advantages of quantitative $^1H-NMR$ analysis are that can be analyzed to identify and quantify, and no reference compounds required for calibration curve. Besides, it allows rapid and simple quantification for hesperidin with an analysis time for only 10 min without any pre-purification steps.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.179-184
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• 2006

Rapid and high-precision positioning with a Global Navigation Satellite System (GNSS) is feasible only when very precise carrier-phase observations can be used. There are two kinds of mathematical models for ambiguity resolution. The first one is based on both pseudorange and carrier phase measurements, and the observation equations are of full rank. The second one is only based on carrier phase measurement, which is a rank-defect model. Though the former is more commonly used, the latter has its own advantage, that is, ambiguity resolution will be freed from the effects of pseudorange multipath. Galileo will be operational. One of the important differences between Galileo and current GPS is that Galileo will provide signals in four frequency bands. With more carrier-phase data available, frequency combinations with long equivalent wavelength can be formed, so Galileo will provide more opportunities for fast and reliable ambiguity resolution than current GPS. This paper tries to investigate phase only fast ambiguity resolution performance with four Galileo frequencies for short baseline. Cascading Ambiguity Resolution (CAR) method with selected optimal frequency combinations and LAMBDA method are used and compared. To validate the resolution, two tests are used and compared. The first one is a ratio test. The second one is lower bound success-rate test. The simulation test results show that, with LAMBDA method, whether with ratio test or lower bound success rate validation criteria, ambiguity can be fixed in several seconds, 8 seconds at most even when 1 sigma of carrier phase noise is 12 mm. While with CAR method, at least about half minute is required even when 1 sigma of carrier phase noise is 3 mm. It shows that LAMBDA method performs obviously better than CAR method.

• Journal of Biosystems Engineering
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• 제25권4호
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• pp.293-300
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• 2000

Automated greenhouse production system often require crop growth monitoring involving accurate quantification of plant physiological properties. Conventional methods are usually burdensome, inaccurate, and harmful to crops. A thermal image analysis system can accomplish rapid and accurate measurements of physiological-property changes of stressed crops. In this research a thermal imaging system was used to measure the leaf-temperature changes of several crops according to nutrient stresses. Thermal images were obtained from lettuce, cucumber, and pepper plants. Plants were placed in growth chamber to provide relatively constant growth environment. Results showed that there were significant differences in the temperature of stressed plants and non-stressed plants. In a case of the both N deficiency and excess, the leaf temperatures of cucumber were $2^{\circ}C$ lower than controlled temperature. The leaf temperature of cucumber was $2^{\circ}C$ lower than controlled temperature only when it was under N excess stress. For the potassium deficiency or excess stress, the leaf temperaures of cucumber and hot pepper were $2^{\circ}C$ lower than controls, respectively. The phosphorous deficiency stress dropped the leaf temperatures of cucumber and hot pepper $2^{\circ}C$ and $1.5^{\circ}C$ below than controls. However, the leaf temperature of lettuce did not change. It was possible to detect the changes in leaf temperature by infrared thermography when subjected to nutrition stress. Since the changes in leaf temperatures were different each other for plants and kinds of stresses, however, it is necessary to add a nutrient measurement system to a plant-growth monitoring system using thermography.