• The Korean Journal of Physiology
• /
• 제16권2호
• /
• pp.111-117
• /
• 1982

Slices of rat corpora lutea(CL) incubated with. prostaglandin $F_{{2{\alpha}}}(PGF_{2{\alpha}})$ in Krebs-Hensenleit (K-H) Ringer solution showed a decrease in $Na^+-K^+$-ATPase activity after 60 min of incubation. However, $PGF_{2{\alpha}}$ in vitro did not alter $Na^+-K^+$-ATPase activity of isolated luteal membrane fractions. Following $PGF_{2{\alpha}}$ induced in vivo luteal regression, reduction of Vmax an elevation of the activation energy above transition temperature of the lipid phase of the membrane occurred without changes of Km, optimum pH and transition temperature. These results suggest that reduction of $Na^+-K^+$-ATPase activity after $PGF_{2{\alpha}}$ treatment may be due to the reduction of the number of enzyme molecules or to masking of the active site of the enzyme without any change in enzyme characteristics. In addition, a change in membrane bound enzyme activity may be an early step in $PGF_{2{\alpha}}$ induced luleolysis.

• 제어로봇시스템학회논문지
• /
• 제12권10호
• /
• pp.1044-1049
• /
• 2006

Multiple sequence alignment is a method to compare two or more DNA or protein sequences. Most of multiple sequence alignment tools rely on pairwise alignment and Smith-Waterman algorithm to generate an alignment hierarchy. Therefore, in the existing multiple alignment method as the number of sequences increases, the runtime increases exponentially. In order to remedy this problem, we adopted a parallel processing suffix tree algorithm that is able to search for common subsequences at one time without pairwise alignment. Also, the cross-matching subsequences triggering inexact-matching among the searched common subsequences might be produced. So, the cross-matching masking process was suggested in this paper. To identify the function of the clusters generated by suffix tree clustering, BLAST and CDD (Conserved Domain Database)search were combined with a clustering tool. Our clustering and annotating tool consists of constructing suffix tree, overlapping common subsequences, clustering gene sequences and annotating gene clusters by BLAST and CDD search. The system was successfully evaluated with 36 gene sequences in the pentose phosphate pathway, clustering 10 clusters, finding out representative common subsequences, and finally identifying functional domains by searching CDD database.

• 한국소음진동공학회논문집
• /
• 제21권10호
• /
• pp.883-889
• /
• 2011

The brand sound of vehicle diesel engine is recently one of the important advantage strategies in the automotive company. Because various noise components masked under high frequency level can be audible in quieter driving situation. Many researches have been carried out for subjective and objective assessments on vehicle sounds and noises. In particular, the interior sound quality has been one of research fields that can give high quality feature to vehicle products. Vehicle interior noise above 500 Hz is usually controlled by sound package parts. The materials and geometries of sound package parts directly affect on this high frequency noise. This paper describes the sound quality evaluation method for the vehicle diesel engine noise to establish objective criteria for sound quality assessment. Considering the sensitivity of human hearing to impulsive sounds such as diesel noise, the human auditory mechanism was simulated by introducing temporal masking in the time domain. Furthermore, each of the human auditory organs was simulated by computer codes, providing reasonable analytical explanations of typical human hearing responses to diesel noise. This method finally provides the sound quality index of vehicle diesel engine noise that includes high frequency intermittent offensive sounds caused by impacting excitations of combustion and piston slap.

• 한국공작기계학회논문집
• /
• 제13권2호
• /
• pp.33-39
• /
• 2004

Sandblasting has recently been developed into a powder blasting technique for brittle materials. In this study, the machinability of $Si_3N_4$-hBN based machinable ceramics are evaluated for micro - pattern making processes using powder blasting. Material properties of the developed machinable ceramics according to the variation of h-BN contents give a good machinability to the ceramics. The effect of scanning times, the size of patterns and variation of BN contents on the erosion depth of samples without mask and samples with different mask patterns in powder blasting of $Si_3N_4$-hBN ceramics are investigated. The Parameters are the impact angle of $90^{\circ}$, the scanning times of nozzle up to 40, and the stand-off distances of 100mm The widths of masked pattern are 0.1mm 0.5mm and 1mm. The powder used is Alumina particles, WA#600. and the blasting pressure of powder is 0.2MPa. Through required experiments, the results are investigated and analyzed. As the results, the machinability of the developed ceramics increases as the BN contents in the ceramics.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.364-364
• /
• 2009

The solar cell is in the spotlight as a future green energy source. In the solar cells based on silicon wafer, the improvement of efficiency is one of crucial issues. One of techniques for high efficiency is texturing on the surface of solar cells. We studied the laser texturing on the surface of multi-crystalline silicon solar cells. The laser texturing followed by chemical etching is adequate for the multi-crystalline structure which have random crystallographic directions. We used the fiber laser for texturing and the SiNx as a masking layer for etching process. We investigated the shapes of holes for texturing in the various laser power conditions and analyzed the holes after removal of thermal damages caused by laser ablation through a 3D profiler.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권9호
• /
• pp.3412-3431
• /
• 2015

This paper considers the effect of co-channel interference on hybrid satellite-terrestrial relay network. In particular, we investigate the problem of amplify-and-forward (AF) relaying in hybrid satellite-terrestrial link, where the relay is interfered by multiple co-channel interferers. The direct link between satellite and terrestrial destination is not available due to masking by surroundings. The destination node can only receive signals from satellite with the assistance of a relay node situated at ground. The satellite-relay link is assumed to follow the shadowed Rice fading, while the channels of interferer-relay and relay-destination links experience Nakagami-m fading. For the considered AF relaying scheme, we first derive the analytical expression for the moment generating function (MGF) of the output signal-to-interference-plus-noise ratio (SINR). Then, we use the obtained MGF to derive the average symbol error rate (SER) of the considered scenario for M-ary phase shift keying (M-PSK) constellation under these generalized fading channels.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권7호
• /
• pp.3319-3338
• /
• 2016

Cloud storage is becoming more and more popular because of its elasticity and pay-as-you-go storage service manner. In some cloud storage scenarios, the data that are stored in the cloud may be shared by a group of users. To verify the integrity of cloud data in this kind of applications, many auditing schemes for shared cloud data have been proposed. However, all of these schemes do not consider the access authorization problem for users, which makes the revoked users still able to access the shared cloud data belonging to the group. In order to deal with this problem, we propose a novel public auditing scheme for shared cloud data in this paper. Different from previous work, in our scheme, the user in a group cannot any longer access the shared cloud data belonging to this group once this user is revoked. In addition, we propose a new random masking technique to make our scheme preserve both data privacy and identity privacy. Furthermore, our scheme supports to enroll a new user in a group and revoke an old user from a group. We analyze the security of the proposed scheme and justify its performance by concrete implementations.

• Journal of Preventive Medicine and Public Health
• /
• 제53권3호
• /
• pp.171-174
• /
• 2020

The coronavirus disease 2019 (COVID-19) pandemic has not only caused significant challenges for health systems all over the globe but also fueled the surge of numerous rumors, hoaxes, and misinformation, regarding the etiology, outcomes, prevention, and cure of the disease. Such spread of misinformation is masking healthy behaviors and promoting erroneous practices that increase the spread of the virus and ultimately result in poor physical and mental health outcomes among individuals. Myriad incidents of mishaps caused by these rumors have been reported globally. To address this issue, the frontline healthcare providers should be equipped with the most recent research findings and accurate information. The mass media, healthcare organization, community-based organizations, and other important stakeholders should build strategic partnerships and launch common platforms for disseminating authentic public health messages. Also, advanced technologies like natural language processing or data mining approaches should be applied in the detection and removal of online content with no scientific basis from all social media platforms. Furthermore, these practices should be controlled with regulatory and law enforcement measures alongside ensuring telemedicine-based services providing accurate information on COVID-19.

• 수산해양기술연구
• /
• 제48권4호
• /
• pp.495-503
• /
• 2012

An acoustic method for discriminating plankton from fish, in Lake Dom Helvecio of Brazil, is developed. The flow of data from this method is comprised of time varied threshold (TVT), dilation filter, bitmap and mask functions. The TVT can, of itself, precisely explain how to select an appropriate value. The final results of the echogram, which only shows plankton by masking fish signals, is used to examine the acoustic density of plankton by depth and time. The results indicate that the acoustic density of the plankton is at a depth of between 5m to 15m, its density is especially high at 10m to 15m. The results of the acoustic density of plankton by time indicate that May 7 is higher in density than May 8. Future study plans include the use of net samples, environmental datasets to identify the abundance and ecology described by the Chaoborus spp. from other species.

• 대한화학회지
• /
• 제33권3호
• /
• pp.315-320
• /
• 1989

철광석 중에 존재하는 미량 금속원소들을 분석하는 방법을 제시하였다. 분석방법은 ammonium pyrrolidinedithiocarbamate(APDC)-methyl isobutyl ketone(MIBK) 추출계와 원자흡수 분광법(AA)를 이용하였다. 철이 유기층으로 추출되는 것을 막기 위하여 가리움제로서 코발트, 니켈 및 구리의 분석시에는 pH $8{\sim}10$에서 citrate를, 그리고 망간 및 구리의 분석시에는 pH 6{\sim}7$에서 tiron을 가하였다. MIBK의 물에 대한 용해도를 줄이기 위해 NaCl을 염석제로 가하였다. 금속 추출용액의 안정도를 증가시키기 위한 방안으로 MIBK 금속 추출물을 질산 수용액으로 역추출하는 것을 검토하였다.