• Development and Reproduction
• /
• v.20 no.4
• /
• pp.359-365
• /
• 2016

Intact germinal vesicle (GV) arrest and release are essential for maintaining the fertility of mammals inducing human. Intact germinal vesicle release, maturation of oocytes is maintained by very complex procedures along with folliculogenesis and is a critical step for embryonic development. Cyclic guanosine monophosphate (cGMP) has been suggested a key factor for meiotic arrest but so far its mechanisms are controversy. In this study we examine the effects of cGMP on germinal vesicle breakdown in cumulus-enclosed oocytes and denuded oocytes. Spontaneous maturation was inhibited by a cGMP agonist, 8-Br-cGMP with concentration dependent manners both in cumulus-enclosed oocytes and denuded oocytes. The inhibitory effect was more severe in denuded oocytes than cumulus-enclosed oocytes. The Rp-8-Br-cGMP and Rp-pCPT-8-Br-cGMP did not severely block GVB compared to 8-Br-cGMP. The spontaneous GVB inhibitory effects were different by the existence of cumulus. Based on them it is suggested that the cumulus modulates the role of cGMP in GV arrest.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.12 no.1
• /
• pp.71-79
• /
• 2016

The main security threats in MANET are integrity and non-repudiation. In the meantime, a lot of secure routing protocols have been designed in order to block these security threats. In this paper, partnership-based authentication technique is proposed in order to provide participation exclusion of network and non-repudiation for the nodes. The proposed technique is a technique that participates in data communication for only the nodes receiving the authentication through the authentication process for the nodes. For this, the proposed technique is largely consists of two steps. The first step is the process that issued the certificate after the reliability for the nodes participating in the network is evaluated. And in the second step, the key exchange agreement with the neighbor nodes is performed and data communication is made after setting security path with responding nodes. The level of security in data transmission is improved because the process of path setting is performed through cooperation with a neighboring nodes having high reliability during the course of these two steps. The superiority of proposed technique in this paper was confirmed through the comparative experiment.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2000.11a
• /
• pp.45-67
• /
• 2000

Broadband access technologies plays an important role in the national information infrastructure. In the evolution path of the information infrastructure, the relative economics of alternative access technology is the most critical determining factor. In this paper, we discuss the economics of local loop access technologies of existing technologies, such as, ADSL, HFC, and new PLC. To do this, we suggest appropriate configuration of access network system and its associated numerical equations. To modelize access network system and drive the numerical equations, we consider the DS (Double Star) and the T&B (Tree ＆ Brench) architecture and analyse the adequate block diagram of each access system for each technology We introduce the density of subscriber as a key variable and the equation of allocating optimal number of cell in a service area. We analyze the relative economics of local loop architecture in two different situations, that is, urban and rural. From the empirical implementation, we found that for the case of urban area, where the cost of cable and infrastructure is not necessary, there is not much difference in the cost per one subscriber. However, for the case of rural region, we found that there is remarkable difference in the cost per one subscriber among technologies. Therefore we conclude that the economics of local loop architecture is depend on the density of subscriber and existing network infrastructures. we hope that this paper contribute to the optimal technology selection of consmer, technology Providers, and government.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.7
• /
• pp.3353-3370
• /
• 2016

The way of combination of Product Perfect Codes (PPCs) is based on the theory of short codes constructing long codes. PPCs have larger embedding rate than Hamming codes by expending embedding columns in a coding block, and they have been proven to enhance the performance of the F₅ steganographic method. In this paper, the proposed modified product codes called MPCs are introduced as an efficient way to embed more data than PPCs by increasing 2^r₂-1-r₂ embedding columns. Unlike PPC, the generation of the check matrix H in MPC is random, and it is different from PPC. In addition a simple solving way of the linear algebraic equations is applied to figure out the problem of expending embedding columns or compensating cases. Furthermore, the MPCs over ℤ₄ have been proposed to further enhance not only the performance but also the computation speed which reaches O(n₁+σ). Finally, the proposed ℤ₄-MPC intends to maximize the embedding rate with maintaining less distortion , and the performance surpasses the existing improved product perfect codes. The performance of large embedding rate should have the significance in the high-capacity of covert communication.

• Journal of Fashion Business
• /
• v.8 no.5
• /
• pp.75-84
• /
• 2004

Fashion Illustration has become a key method in expressing Fashion, and is being applied in various fields of the modern world, where changes are so rapid that prescribing trends are meaningless. Fashion Illustration was stimulated through progress of wood block printing and development of printing techniques, and grew with fashion magazines. Fashion Illustration advanced along with the appearance of newspapers and magazines that were emerged due to historical demands such as development of printing techniques, spacial spread of human life, obliteration of traditional societies, diffusion of education systems, progress in postal systems, and appearance of commercial broadcast. Fashion Illustration showed growth and decline along with the influence of mass media such as magazines and photography, and the general publics demand. In this study, the author reviews Le Nouvau Mercure Galant, the magazine that first dealt with Fashion Illustrations. The author analyses the magazine in six stages of formation, growth, revolution, golden-age, decline, and reconstruction, to develope a theoretical analysis of Fashion Illustration and to give direction of use of Fashion Illustration in the future.

• Nuclear Engineering and Technology
• /
• v.46 no.5
• /
• pp.641-654
• /
• 2014

A new computer code, named CORONA (Core Reliable Optimization and thermo-fluid Network Analysis), was developed for the core thermo-fluid analysis of a prismatic gas cooled reactor. The CORONA code is targeted for whole-core thermo-fluid analysis of a prismatic gas cooled reactor, with fast computation and reasonable accuracy. In order to achieve this target, the development of CORONA focused on (1) an efficient numerical method, (2) efficient grid generation, and (3) parallel computation. The key idea for the efficient numerical method of CORONA is to solve a three-dimensional solid heat conduction equation combined with one-dimensional fluid flow network equations. The typical difficulties in generating computational grids for a whole core analysis were overcome by using a basic unit cell concept. A fast calculation was finally achieved by a block-wise parallel computation method. The objective of the present paper is to summarize the motivation and strategy, numerical approaches, verification and validation, parallel computation, and perspective of the CORONA code.

• Journal of the Society of Naval Architects of Korea
• /
• v.51 no.2
• /
• pp.154-161
• /
• 2014

Naval ships have hull appendages which are more exposed to the outside because of its small block coefficient compared with commercial ships. These exposed hull appendages like skeg, strut and shaft line affect the maneuverability of a ship. The effect of hull appendages has considered at initial design stage to estimate more accurate maneuverability. In this paper, sensitivity analysis is used to analyze the effect on maneuverability by hull appendages. 3 DOF maneuvering equations based on Mathematical Modelling Group (MMG) model are used and propeller & rudder model are modified to reflect the characteristics of twin propeller & twin rudder. Numerical maneuvering simulations (Turning test, Zig-zag test) for benchmark naval vessel, David Taylor Model Basin (DTMB) 5415 are performed. In every simulation, it is calculated that stability indices and maneuverability characteristics (Tactical Dia., Advance, 1st Overshoot, Time of complete cycle) with respect to the parameters (area times lift coefficient slope, attachment location) of hull appendages. As a result, two regression formulas are established. One is the relation of maneuverability characteristics and stability indices and the other is the relation of stability indices and hull appendages.

• 한국기계연구소 소보
• /
• s.19
• /
• pp.125-139
• /
• 1989

As an adaptive control function generator, the CMAC (Cerebellar Model Arithmetic or Articulated Controller) based learning control has drawn a great attention to realize a rather robust real-time manipulator control under the various uncertainties. There remain, however, inherent problems to be solved in the CMAC application to robot motion control or perception of sensory information. To apply the CMAC to the various unmodeled or modeled systems more efficiently, it is necessary to analyze the effects of the CMAC control parameters on the trained net. Although the CMAC control parameters such as size of the quantizing block, learning gain, input offset, and ranges of input variables play a key role in the learning performance and system memory requirement, these have not been fully investigated yet. These parameters should be determined, of course, considering the shape of the desired function to be trained and learning algorithms applied. In this paper, the interrelation of these parameters with learning performance is investigated under the basic learning schemes presented by authors. Since an analytic approach only seems to be very difficult and even impossible for this purpose, various simulations have been performed with pre specified functions and their results were analyzed. A general step following design guide was set up according to the various simulation results.

• Journal of Digital Convergence
• /
• v.10 no.11
• /
• pp.389-394
• /
• 2012

The cloud computing is a system that provides IT resources service by using internet technologies, which grabs lots of attention today. Though cloud storage services provide service users with convenience, there is a problem in which data confidentiality is not guaranteed because it is hard for data owners to control the access to the data. This article suggested the technique by applying Public-Key Cryptosystem only to a block after dividing users' data into blocks in order to protect users' data in cloud system. Thus confidentiality and integrity are given to users' data stored in cloud storage server.

• Journal of Magnetics
• /
• v.8 no.1
• /
• pp.18-23
• /
• 2003

In our previous work, microstructure and magnetic properties of two-phase exchange-coupled $Sm_2Fe_{15}Ga_2C_{x}$/$\alpha$-Fe nanocomposites have been investigated by means of x-ray diffraction, transmission electron microscopy and magnetization measurement. It was found the exchange coupling between the magnetically hard phase $Sm_2Fe_{15}Ga_2C_{x}$ and the magnetically soft one ${\alpha}$-Fe results in an enhancement of the remanence. The sizes of crystallites of both phases are, however much larger than the Block domain-wall width of the magnetically hard phase. This microstructure gives rise to a concave demagnetization curve and consequently reduces the maximum energy Product. In order to improve their magnetic properties, a few Percent of Zr, which may be effective to refine the microstructure through rapid quenching, was introduced into the nanocomposites. The addition of Zr was found to improve the magnetic properties significantly, Under optimum heat-treatment conditions, the remanence, coercivity and maximum energy Product increase from 0.65 T, 0.48 T and 50 kJ/$m^{3}$ for the Zr-free sample to 0.72 T, 0.77 T and 71.6 kJ/$m^{3}$ for the 1 at.% Zr-containing one, respectively, The improvements of magnetic properties are due to the refinement of microstructure by the addition of Zr.