• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.815-824
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• 2016

The fuel assembly for pressurized water reactor (PWR) consists of fuel rod bundle, spacer grid and bottom/top end fittings. The cooling water in high pressure and temperature is introduced in lower plenum of reactor core and directed to upper plenum through the subchannel which is formed between the fuel rods. The main thermal-hydraulic performance parameters for the PWR fuel are pressure drop and critical heat flux in normal operating condition, and quenching time in accident condition. The Korea Atomic Energy Research Institute (KAERI) has been developing an advanced PWR fuel, dual-cooled annular fuel and accident tolerant fuel for the enhancement of fuel performance and the localization. For the key thermal-hydraulic technology development of PWR fuel, the KAERI LWR fuel team has conducted the experiments for pressure drop, turbulent flow mixing and heat transfer, critical heat flux(CHF) and quenching. The computational fluid dynamics (CFD) analysis was also performed to predict flow and heat transfer in fuel assembly including the spent fuel assembly in dry cask for interim repository. In addition, the research cooperation with university and nuclear fuel company was also carried out to develop a basic thermal-hydraulic technology and the commercialization.

• Journal of Life Science
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• v.27 no.7
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• pp.739-745
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• 2017

In all mammalian species, progesterone is essential in the preparation for and maintenance of pregnancy. $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) predominantly converts progesterone into its biologically inactive form $20{\alpha}$-hydroxyprogesterone ($20{\alpha}$-OHP), and plays a crucial role in the termination of pregnancy and initiation of parturition. In this study, we characterized the expression and localization of $20{\alpha}$-HSDinthe testis of MediKinetics $Micropigs^{(R)}$. The testes were collected at days 6, 9, 12, 18, and 21 after birth. The $20{\alpha}$-HSD mRNA was found to be expressed in the testis at day 6 after birth by RT-PCR. The highest level of mRNA expression in the testis was detected on day 21 after birth. However, the mRNA was not detected in the placenta after parturition. Western blot for $20{\alpha}$-HSD reveal that the specific 37-kDa band was detected in immature pig testis. However, this band was not detected in testis tissue at day 6 after birth. In the immunohistochemical analysis of the testis, $20{\alpha}$-HSD was detected in the Sertoli cells and Leydig cells. Taken together, our study shows for the first time that the $20{\alpha}$-HSD mRNA and protein are expressed in pig testis after birth. Further investigation is required to elucidate the functional mechanisms of $20{\alpha}$-HSD in pig testis after birth.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.193-198
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• 2008

The current study was designed to extend the technique of spermatogonial transplantation to economically important pig model We evaluated the efficiency of pig to pig transplantation. Donor testis cells were harvested from testes obtained at castration of 10- to 14-day-old boars and were labeled with fluorescent marker(PKH26) before transplantation. The presence of infused dye or labeled pig testicular cells was confirmed in the seminiferous tubules from recipient pig. The most effective procedure of intratubular germ cell transfer was to insert an fine needle ($21{\sim}25$ gauge) through the cauda epididymis and testis into the rete testis under ultrasound guidance. Infusion of $5{\sim}7ml$ of dye solution or cell suspension could fill the rete and up to 50% of seminiferous tubules of 14-week-old boars. Testis were examined for the presence and localization of labeled donor cells immediately after transplantation and labeled donor cells were found in numerous seminiferous tubules from recipient pig testes. These results indicate that germ cell transplantation is feasible in recipient pig testis. This study represents successful spermatogonial transplantation between individual animals in a livestock species.

• The Korean Journal of Ceramics
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• v.6 no.2
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• pp.100-102
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• 2000

Co fine particles were dispersed in Au metal and $AlO_x$ amorphous matrices by vacuum evaporation and rf-sputtering, respectively, thus forming granular composite films having chemical compositions of $Co_{0.59}-Au_{0.41}$ and $Co_{0.52}/(AlO_x$)_{0.48}$. The films were annealed at 200~$500^{\circ}C$ to increase the size of the Co particles, from 30$\AA$ to 180$\AA$ in the Au matrix and 40$\AA$ to 180$\AA$ in the $AlO_x$ matrix, as revealed by X-ray diffraction analysis. The Co metal in as-deposited films have saturation magnetization equivalent to that of bulk Co, which is unchanged by the annealing, showing that the Co metal is not oxidized by the annealing. Magneto-optical Kerr rotation measured at $\lambda$=400-900nm for the $Co_{0.59}-Au_{0.41}$ film as deposited is larger than that calculated for the composition. The rotation increases as the film is annealed at $200^{\circ}C$ and $300^{\circ}C$, approaching to that of bulk Co. The Kerr rotation for the $Co_{0.52}-(AlO_x)_{0.48}$ film as deposited is smaller than that calculated for the composition based on Bruggeman effective medium theory. However, the rotation increases much, exceeding the rotation of the bulk Co as annealed at $300^{\circ}C$ and $400^{\circ}C$. As a possible origin of the marked magneto-optical enhancement a weak localization of light in granular structure is suggested.

• KDI Journal of Economic Policy
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• v.14 no.3
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• pp.3-21
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• 1992

By localizing the production of core parts and intermediate goods previously imported from Japan, Korean firms have been striving to increase their market share and profit in the final goods market in which Japanese firms are dominating. Korean producers' efforts, however, have often been thwarted by Japanese suppliers' "strategic" behavior. This competitive strategy involves Japanese exporters supplying parts and intermediate goods at very high prices until Korean firms must locally develop them, and then setting the prices far below the previous level so that the profitability of localization is dramatically reduced, or even means a loss for the Korean manufacturer. This paper intends to explain the strategic behavior of Japanese firms through the concepts of strategic interactions and joint economies. Strategic interactions can be aggressive or accommodating depending on whether competitors are dealing with strategic substitutes or complements. Joint economies exist in multi-stage competition when competition in the previous state favorably influences "profits" of the ensuing stage. Competiton between Korean and Japanese firms (a two-stage game involving production and technology rivalries) can be characterized by joint economies and strategic substitutes: joint economies since technological improvement results in more profits in the production stage; and strategic substitutes since an increase in marginal profits of one firm brings about a decrease in marginal profits of the other in a duopolitic production stage. This implies that the flood of "low price" Japense substitutes is an almost "natural" phenomenon in the context of the duopolistic market described in this paper. In the technology competition stage, on the other hand, technology development and technology transfer can be either strategic complements or substitutes. This implies that, in typical comparative static analyses, the effect of changes in exogenous variables cannot be expected a priori. Thus it becomes very difficult to determine the desirability of applying various policy measures such as countervailing duties, R&D subsidies, and creating demand for localized products. For these reasons, it is indeed likely that the measures suggested as means of circumventing the strategic behavior of Japanese firms (and enhancing technological development of Korean firms) may not work.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.901-910
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• 2006

Poly(3-hydroxybutyrate) [P(3HB)] is a microbial polyester intracellularly accumulated as distinct granules in numerous microorganisms as an energy and carbon storage material. Recombinant Escherichia coli harboring the heterologous P(3HB) biosynthesis genes accumulates large amounts of P(3HB) granules, yet the granule-associated proteins have not been identified. Therefore, this study reports on an analysis of the P(3HB) granule-associated proteome in recombinant E. coli. Fiye proteins out of 7 spots identified were found to be involved in functions of translation, heat-stress responses, and P(3HB) biosynthesis. Two of the major granule-associated proteins, IbpA/B, which are already known to bind to recombinant proteins forming inclusion bodies in E. coli, were further analyzed. Immunoblotting and immunoelectron microscopic studies with IbpA/B antibodies clearly demonstrated the binding and localization of IbpA/B to P(3HB) granules. IbpA/B seemed to play an important role in recombinant E. coli producing P(3HB) by stabilizing the interface between the hydrophobic P(3HB) granules and the hydrophilic cytoplasm. Thus, IbpA/B were found to act like phasins in recombinant E. coli, as they are the major proteins bound to the P(3HB) granules, affect the morphology of the granules, and reduce the amount of cytosolic proteins bound to the P(3HB) granules.

• Molecules and Cells
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• v.40 no.12
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• pp.954-965
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• 2017

Mammalian genomes are well established, and highly conserved regions within odorant receptors that are unique from other G-protein coupled receptors have been identified. Numerous functional studies have focused on specific conserved amino acids motifs; however, not all conserved motifs have been sufficiently characterized. Here, we identified a highly conserved 18 amino acid sequence motif within transmembrane domain seven (CAS-TM7) which was identified by aligning odorant receptor sequences. Next, we investigated the expression pattern and distribution of this conserved amino acid motif among a broad range of odorant receptors. To examine the localization of odorant receptor proteins, we used a sequence-specific peptide antibody against CAS-TM7 which is specific to odorant receptors across species. The specificity of this peptide antibody in recognizing odorant receptors has been confirmed in a heterologous in vitro system and a rat-based in vivo system. The CAS-TM7 odorant receptors localized with distinct patterns at each region of the olfactory epithelium; septum, endoturbinate and ectoturbinate. To our great interests, we found that the CAS-TM7 odorant receptors are primarily localized to the dorsal region of the olfactory bulb, coinciding with olfactory epithelium-based patterns. Also, these odorant receptors were ectopically expressed in the various non-olfactory tissues in an evolutionary constrained manner between human and rats. This study has characterized the expression patterns of odorant receptors containing particular amino acid motif in transmembrane domain 7, and which led to an intriguing possibility that the conserved motif of odorant receptors can play critical roles in other physiological functions as well as olfaction.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.1
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• pp.7-14
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• 2013

Presently, there are many different technologies used for position detection. However, as signal-receiving devices operating in different locations must detect the precise position of objects located at long distances, it is essential to know the precise time at which an object's or a user's terminal device sends a signal. For this purpose, the existing time of arrival (ToA) technology is not sufficiently reliable, and the existing time difference of arrival (TDoA) technology is more suitable. If a TDoA-based electric surveillance system and other tracking devices fail to achieve precise time-synchronization between devices with separation distance operation, it is impossible to obtain correct TDoA values from the signals sent by the signal-receiving devices; this failure to obtain the correct values directly affects the location estimation error. For this reason, the technology for achieving precise time synchronization between signal-receiving devices in separation distance operation, among the technologies previously mentioned, is a core technology for detecting TDoA-based locations. In this paper, the accuracy of the proposed time synchronization and the measurement error in the TDoA-based location detection technology is evaluated. The TDoA-based location measurement error is significantly improved when using the proposed method for time-synchronization error reduction.

• Korean Journal of Labor Studies
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• v.24 no.2
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• pp.367-408
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• 2018

This study examines the features of globalization process in GM and Hyundai Motors, especially in the expansion into China auto market, through a joint venture(hereafter JV) research center. Due to the large scale market in China and the 50:50 JV, the two companies had to respond in some way to the Chinese government's request for localization of research and development functions, and their response affected the role of the JV research center. Even though the improvement in technological capability expected from the JV by the Chinese side did not appear well in the early stage in both JV, but relatively the Shanghai GM JV research center had a technological progress compared to the Beijing Hyundai JV research center. This paper explains the differences in the technical capabilities of the two JV research center, despite the same type of JV, as the difference between the status of the Chinese partner and the global strategy of the parent company. SAIC, a Chinese partner in Shanghai GM as a top-tier company, not only has been strongly demanding technology transfer from GM since the beginning of the JV, but has also made efforts to improve its own technical capabilities. Meanwhile, BAIC, a Chines partner in Beijing Hyundai as a mid-tier company, has not been strongly demanding technology transfer and lacked its own research base. Regarding the parent company's global strategy, although both companies controlled the core areas of research and development by their parent companies, GM actively considered using the Chinese RV to develop Chinese and emerging country vehicles. On the other hand, Hyundai Motors responded to the localization demand of the Chinese government while paying more attention to preventing technology leakage through its independent research center in China. The above discussion shows that the process of globalization of a company is a political process in which the global strategy of the parent company and the demands of the stakeholders surrounding the subsidiary are collided and compromised, rather than a process in which the harmony and cooperation between the parent company and its subsidiaries are smoothly achieved as the parent company's policies are unilaterally implemented.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1827-1836
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• 2022

Disasters that occur unexpectedly are difficult to predict. In addition, the scale and damage are increasing compared to the past. Sometimes one disaster can develop into another disaster. Among the four stages of disaster management, search and rescue are carried out in the response stage when an emergency occurs. Therefore, personnel such as firefighters who are put into the scene are put in at a lot of risk. In this respect, in the initial response process at the disaster site, robots are a technology with high potential to reduce damage to human life and property. In addition, Light Detection And Ranging (LiDAR) can acquire a relatively wide range of 3D information using a laser. Due to its high accuracy and precision, it is a very useful sensor when considering the characteristics of a disaster site. Therefore, in this study, development and experiments were conducted so that the robot could perform real-time monitoring at the disaster site. Multi-sensor module was developed by combining LiDAR, Inertial Measurement Unit (IMU) sensor, and computing board. Then, this module was mounted on the robot, and a customized Simultaneous Localization and Mapping (SLAM) algorithm was developed. A method for stably mounting a multi-sensor module to a robot to maintain optimal accuracy at disaster sites was studied. And to check the performance of the module, SLAM was tested inside the disaster building, and various SLAM algorithms and distance comparisons were performed. As a result, PackSLAM developed in this study showed lower error compared to other algorithms, showing the possibility of application in disaster sites. In the future, in order to further enhance usability at disaster sites, various experiments will be conducted by establishing a rough terrain environment with many obstacles.