• Journal of Microbiology and Biotechnology
• /
• v.14 no.6
• /
• pp.1239-1248
• /
• 2004

The methylotrophic yeast Hansenula polymorpha has been extensively studied as a model organism for methanol metabolism and peroxisome biogenesis. Recently, this yeast has also attracted attention as a promising host organism for recombinant protein production. Here, we describe the fabrication and evaluation of a DNA chip spotted with 382 open reading frames (ORFs) of H. polymorpha. Each ORF was PCR-amplified using gene-specific primer sets, of which the forward primers had 5'-aminolink. The PCR products were printed in duplicate onto the aldehyde-coated slide glasses to link only the coding strands to the surface of the slide via covalent coupling between amine and aldehyde groups. With the partial genome DNA chip, we compared efficiency of direct and indirect cDNA target labeling methods, and found that the indirect method, using fluorescent-labeled dendrimers, generated a higher hybridization signal-to-noise ratio than the direct method, using cDNA targets labeled by incorporation of fluorescence-labeled nucIeotides during reverse transcription. In addition, to assess the quality of this DNA chip, we analyzed the expression profiles of H. polymorpha cells grown on different carbon sources, such as glucose and methanol, and also those of cells treated with the superoxide­generating drug, menadione. The profiles obtained showed a high-level induction of a set of ORFs involved in methanol metabolism and oxidative stress response in the presence of methanol and menadione, respectively. The results demonstrate the sensitivity and reliability of our arrays to analyze global gene expression changes of H. polymorpha under defined environmental conditions.

• Proceedings of the KSAR Conference
• /
• 2003.06a
• /
• pp.56-56
• /
• 2003

Beta-catenin is very important in early development including involvement in cell adhesion, cell signaling, and developmental fate specification. Cell-cell interaction is an important process during mammalian embryonic development. In preimplantation embryos, embryonic compaction is the process of increased cellular flattening and adhesion of junctional complexes and results in a polarized distribution. Beta-catenin is associated with embryonic compaction in mammals. Here, we examined the relationship between beta-catenin expression and compaction in porcine embryos derived from in vitro fertilization. First of all, we investigated beta-catenin expression in each embryonic developmental stage and also focused on expression pattern according to full, partial and non-compaction at morula stage. We used the immunocyto-chemical method in this research. To confirm compaction affects on the embryonic development, we compared between compaction and developmental rates to the blastocyst. The result showed that compaction and non-compaction rates were 14.6% and 63.8% at 4 days after IVF, respectively The developmental rates to the blastocyst and their total cell number were 50.9% vs 36.4% and 41.4$\pm$11.5 vs 26.8$\pm$12.7 in compaction and non-compaction groups. Although no difference was detected in the ratio of ICM to total cells between two groups, total cell number of the blastocysts in compaction group was superior to that of the blastocysts in non-compaction group (P<0.05). Expression of beta-catenin appeared in the boundary of membrane surface between blastomeres in 2- and 4-cell stage, and observed irregular pattern from 8-cell to blastocyst stage. We also investigated beta-catenin expression pattern according to the degree of compaction in the 3 groups; full, partial (>50%) and non-compaction. The expression signal in fully compacted embryos was stronger than those of partial and non-compacted embryos. Especially, beta-catenin expression appeared various patterns in morula stage suggesting the aberrant distribution of beta-catenin is affected by compaction patterns. Our results suggest that abnormal beta-catenin expression was affected by embryo quality and further development in porcine embryos in vitro.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.6
• /
• pp.681-691
• /
• 2017

In the clutter environment, it is necessary to update the target tracking filter by detecting the target signal among many measured value data obtained via the radar system, the track does not diverge, and tracking performance is maintained. The method of associating the measurement most relevant to the target track among numerous measurement values is referred to as data association. PSNF and PSNF-m are data association methods of SN-series. In this paper, we provide an IPSNF-m(Integrated Probabilistic Strongest Neighbor Filter-m) algorithm with a track management method based on the track existence probability in PSNF-m algorithm. This algorithm considers not only the presence of the target but also the case where the target is present but not detected. Calculating the probability of each caseenables efficient management. In order to verify the performance of the proposed IPSNF-m, the track existence probability of the IPSNF algorithm applying the track management technique to PSNF, which is known to have similar performance to PSNF-m, is derived. Through simulation in the same environment, we compare and analyze the proposed algorithm with RMSE, Confirmed True Track, and Track Existence Probability that show better performance in terms of track retention and estimation than the existing PSNF-m and IPSNF algorithms.

• Journal of Broadcast Engineering
• /
• v.19 no.4
• /
• pp.439-452
• /
• 2014

This paper suggests the method to extend service area by using the transmit offset delay in T-DMB single frequency network (SFN). In general, synchronization of the transmit time of all site can be done by using the reference clock of GPS, which dose not reflect the details geographical characteristics and transmit specifications of each site. Applying the site-specific transmit offset delay, we could extend the service area of SFN T-DMB. Applying the transmit offset delay, it is found that the signal quality in the region of weak receive field strength was improved and upto 4~8 km service area expansion was achieved by satisfying the minimum field strength ($45dB{\mu}V/m$) recommended by the Korea Communications Commission (KCC). Site-specific offset delay was calculated considering the geographic service area characteristics, distribution of electric field strength between neighboring sites and site-specific service target area. Experiments were carried out in order to analyze impact of calculated offset delay on the T-DMB SFN and also to confirm that the offset delay extends T-DMB service coverage. The experiment was done in metropolitan T-DMB service areas.

• Journal of Distribution Science
• /
• v.16 no.3
• /
• pp.79-86
• /
• 2018

Purpose - Many retail stores tend to use scarcity-laden message in order to influence consumers, where scarcity refers to insufficiency of product supply or time of availability. For example, inside stores, the displayed products are often accompanied by scarcity message such as 'exclusive offer, limited time only.' According to past research, scarcity has a positive effect on product evaluation, since scarcity can acts as a signal of consumer demand, and thus product quality. Prior studies argue that consumers face a scarce product, they logically infer that other consumers buying the product in large numbers cause the scarcity. We propose that scarcity can be interpreted as a sales tactic artificially created by retail stores in order to increase sales of product. Research design, data, and methodology - We use a persuasion knowledge perspective framework to develop our hypotheses. In the present research, we show that product curation type is a key variable that moderates consumer response to scarcity, and thus the scarcity effect on product evaluation. Results - In this research, we showed when scarcity-laden message was used inside the store using consumer-centric curation message, scarcity had a positive effect on product evaluation. In contrast, when scarcity-laden message was used inside the store using marketer-centric curation message, the positive of scarcity message on product evaluation was diluted. Conclusions - Our study makes two important contributions to the literature on consumer response to scarcity. First, we identify a variable - namely, product curation type - that determines when either 'scarcity = good' or 'scarcity = marketing tactic' interpretation is likely to be dominant. Second, we cite persuasion knowledge perspective to explain the moderating function of product curation type in a retail store-related scarcity context. This research is relevant to practitioners, such as brand manager, retail environment manager, and advertising agencies, for the effective use for the scarcity-laden message in retail. The proposed moderator can operate in many real-life situations in retail where consumers are exposed to scarcity. And curation message related to scarcity has been facilitated by the inner-retail activities. These factors of the marketplace indicate that the boundary conditions of scarcity can have a significant effect on real-life consumer judgment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.8C
• /
• pp.575-582
• /
• 2008

In this paper we described the process and the results of real-time implementation of G.729.1 wideband speech codec which is standardized in SG15 of ITU-T. To apply the codec on ARM926EJ-S(R) processor core. we transformed some parts of the codec C program including basic operations and arithmetic functions into assembly language to operate the codec in real-time. G.729.1 is the standard wideband speech codec of ITU-T having variable bit rates of $8{\sim}32kbps$ and inputs quantized 16 bits PCM signal per sample at the rate of 8kHz or 16kHz sampling. This codec is interoperable with the G.729 and G.729A and the bandwidth extended wideband($50{\sim}7,000Hz$) version of existing narrowband($300{\sim}3,400Hz$) codec to enhance voice quality. The implemented G.729.1 wideband speech codec has the complexity of 31.2 MCPS for encoder and 22.8 MCPS for decoder and the execution time of the codec takes 11.5ms total on the target with 6.75ms and 4.76ms respectively. Also this codec was tested bit by bit exactly against all set of test vectors provided by ITU-T and passed all the test vectors. Besides the codec operated well on the Internet phone in real-time.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.5
• /
• pp.518-523
• /
• 2017

This paper proposes a novel denoising method based on non-local(NL) means. The NL-means algorithm is effective for removing an additive Gaussian noise, but the denoising parameter should be controlled depending on the noise level for proper noise elimination. Therefore, the proposed method optimizes the denoising parameter according to the noise levels. The proposed method consists of two processes: off-line and on-line. In the off-line process, the relations between the noise level and the denoising parameter of the NL-means filter are analyzed. For a given noise level, the various denoising parameters are applied to the NL-means algorithm, and then the qualities of resulting images are quantified using a structural similarity index(SSIM). The parameter with the highest SSIM is chosen as the optimal denoising parameter for the given noise level. In the on-line process, we estimate the noise level for a given noisy image and select the optimal denoising parameter according to the estimated noise level. Finally, NL-means filtering is performed using the selected denoising parameter. As shown in the experimental results, the proposed method accurately estimated the noise level and effectively eliminated noise for various noise levels. The accuracy of noise estimation is 90.0% and the highest Peak Signal-to-noise ratio(PSNR), SSIM value.

• YAKHAK HOEJI
• /
• v.59 no.3
• /
• pp.98-106
• /
• 2015

Analytical method for related substances can be categorized into two methods depending on the necessity of reference standard (RS). The analytical method of related substances with RS is fast and accurate, but it's very expensive and technically difficult to synthesize RS due to their complicated structure. Another method is using relative retention time (RRT) and relative response factor (RRF) which are already validated with RS. Validation of this method is not easy and time consuming, but once it has been developed, it can save cost and time. In this study, we developed the analytical method for related substances of fenofibrate using RRT and RRF. We validated the method by evaluating specificity, linearity, accuracy and precision according to the "Manual for Guideline Application for Validation of Analytical Procedures" of MFDS. Also, we calculated RRT and RRF between fenofibrate and fenofibrate related substances. The results of this study showed high specificity for fenofibrate and fenofibrate related substances. Correlation coefficient(r) of all substances were more than 0.99, and the recovery of fenofibrate, fenofibrate related substance I, II and III were 99.44%, 100.84%, 99.14% and 101.58%, respectively. Precision of fenofibrate and its related substances were ranged between RSD 0.29% and 0.93%. Quantification limits of fenofibrate, fenofibrate related substance I, II and III were determined to be $0.03{\mu}g/ml$, $0.05{\mu}g/ml$, $0.04{\mu}g/ml$ and $0.02{\mu}g/ml$, respectively by confirming signal to noise ratio of each chromatogram. The RRT for fenofibrate related substance I, II and III were determined to be 0.35, 0.41 and 1.34, respectively. Also, the RRF for fenofibrate related substance I, II and III were determined to be 1.28, 0.98 and 0.79, respectively. The developed method was applied to determine contents for fenofibrate related substances in commercial fenofibrate (active pharmaceutical ingredient). As a result, developed analytical methods of related substances will be used for revising the monograph of fenofibrate in Korean Pharmacopoeia revision and contribute quality control of drugs by improving cost and time consuming problem of RS.

• Geophysics and Geophysical Exploration
• /
• v.20 no.1
• /
• pp.43-48
• /
• 2017

The applicability of refraction survey has been tested using a wave glider widely used in long-term ocean observations around the world. To record seismic refractions, a single channel streamer with metal weight and a seismic recording system were mounted on the wave glider. We used GPS precise time synchronization signal and radio frequency (RF) communication to synchronize shot and recorder triggers and to control acquired data quality in real time. When the wave glider is positioned close to the set point, a 2,000 J sparker is exploded along the designed track at 2 second intervals. Through the test survey, we were able to successfully acquire refractions from the subsurface.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.6
• /
• pp.809-818
• /
• 2019

Since January 1, 2020, the International Maritime Organization (IMO) has put in place strong regulations to reduce air pollution caused by ships by lowing the upper limit of ship fuel oil sulfur content from 3.5% to 0.5% for ships passing through all sea areas around the world. Although it is important to reduce air pollutants by using fuel oil with low sulfur content, reducing the amount of energy waste through the economic operation of a ship can also help reduce air pollutants. Ships can follow designated routes accurately even under the influence of noise using autopilot systems. However, regardless of their quality, the performance of these systems is af ected by noise; heading angles with added measurement noise from the gyroscope are input into the autopilot system and degrade its performance. A technique to solve these problems reduces noise effects through the application of a Kalman filter, which is widely used in condition estimation. This method, however, cannot completely eliminate the effects of noise. Therefore, to further improve noise removal performances, in this study we propose a better denoising method than the Kalman filter technique by applying a multi-layer perceptron (MLP) in forward direction motion and a Kalman Filter in rotation motion. Simulations show that the proposed method improves forward direction motion by preventing the malfunction of a rudder more so than merely using a Kalman Filter.