• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.357-364
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• Journal of Science Education
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• v.38 no.3
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• pp.525-542
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• 2014

This study was performed to look into the difficulty of students in understanding science stories in 6th grade science textbooks and to analyze those factors. To do this, 6th grader (N=65) were selected from J Elementary School located in Gyeonggi-do Siheung-si as study subjects. 26 science stories in 6th grade science textbooks were classified by field and context (complement of knowledge, science history of scientists, science in life, cutting-edge science technology, environment issues) in which the characteristics were investigated and analyzed. Also, a survey about the difficulty in understanding science stories(26 items) was conducted(65 students) and a semi-structured interview was conducted for students to clarify the meaning of collected data from surveys(4 students). As result of analyzing surveys on science story context in science textbooks and interviews, 4 fields of 'energy,' 'matter,' 'life,' and 'earth' were evenly mentioned. Science in life and complement of science knowledge were mentions most for context and this had relation with the characteristic of science textbooks to provide many opportunities to apply learned knowledge in actual social issues. Reactions of students on science stories were mostly positive that they help studying science, but there was also difficulty in well understanding science stories. Difficulty of understanding context, problems of context suggesting methods, difficulty of science terminology, lack of interest, and etc. were analyzed as factors. Specific causes were mentioned to be description type class, unimportant context, lack of explanation on suggested context, problem of pictures by students.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.229-236
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• 2006

Purpose: This study was conducted to search for the type of technical error in DEXA(dual-energy X-ray absorptiometry) and the effect of error to measurement of BMD. Materials and Methods: The changes of BMD($g/cm^2$, T-score) by patients information(Age, Weight, Height, Manopause age) input error and Confirming ROI error were investigated. Using spine phantom, we canned 10 times by age(5, 10), weight(10, 20 kg), height(5, 10 cm), manopause age(5, 10) increase & decrease respectively. Scanning region(L-spine, femur, Forearm) of 10 patients was calculated by changing ROI respectively. Analysis of difference for mean(precision 1%) were carried out. Results: The error of patient information(Age, Weight, Height, Manopause age) was not changed differently. In confirming ROI, the BMD and T-score of L-spine involving T-12 was decreased to $0.063\;g/cm^2$, 0.3 and involving L-5 increased to $0.077\;g/cm^2$, 0.5. In narrowing 1 cm of vertical line of ROI, the BMD and T-score decreased to $0.006\;g/cm^2$, 0.1 and in 2 cm, $0.021\;g/cm^2$, 0.15, each. In hip ROI, Upper and left shift(0.5 cm) of line was not influenced BMD and T-score. In 0.5 cm lower shift(lesser trochanter below), the BMD and T-score increased $0.031\;g/cm^2$, 0.3 and in 1 cm $0.094\;g/cm^2$, 0.65, each. In forearm ROI, the BMD and T-score decreased $0.042\;g/cm^2$, 0.9 involving 1 cm lower wrist. And expanding 1 cm of vertical line, the BMD and T-score decreased $0.008\;g/cm^2$, 0.1 and in 2 cm, $0.021\;g/cm^2$, 0.3, each. The L-spine, hip, forearm ROI error was changed differently. Conclusion: There are so many kinds of technical error in BMD processing. Errors according to age, weight, height, manopause age did not influent to $BMD(g/cm^2)$ and T-score. There are mean differences BMD and T-score in confirming ROI. For the precision exam, in L-spine processing, L1-4 have to confirmed without shift of ROI vertical line. In hip processing, the ROI have to included greater trochanter, femur head and lesser trochanter. In forearm processing, the ROI have to included wrist, radius and ulnar.

• Asia pacific journal of information systems
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• v.17 no.2
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• pp.49-81
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• 2007

Research in the IS (Information Systems) outsourcing has focused on the importance of legal contracts and partnerships between vendors and clients. Without detailed legal contracts, there is no guarantee that an outsourcing vendor would not indulge in self-serving behavior. In addition, partnerships can supplement legal contracts in managing the relationship between clients and vendors legal contracts by itself cannot deal with all the complexity and ambiguity involved with IS outsourcing relationships. In this paper, we introduce a psychological contract (between client and vendor) as an important variable for IS outsourcing success. A psychological contract refers to individual's mental beliefs about his or her mutual obligations in a contractual relationship (Rousseau, 1995). A psychological contract emerges when one party believes that a promise of future returns has been made, a contribution has been given, and thus, an obligation has been created to provide future benefits (Rousseau, 1989). An employmentpsychological contract, which is a widespread concept in psychology, refers to employer and employee expectations of the employment relationship, i.e. mutual obligations, values, expectations and aspirations that operate over and above the formal contract of employment (Smithson and Lewis, 2003). Similar to the psychological contract between an employer and employee, IS outsourcing involves a contract and a set of mutual obligations between client and vendor (Ho et al., 2003). Given the lack of prior research on psychological contracts in the IS outsourcing context, we extend such studies and give insights through investigating the role of psychological contracts between client and vendor. Psychological contract theory offers highly relevant and sound theoretical lens for studying IS outsourcing management because of its six distinctive principles: (1) it focuses on mutual (rather than one-sided) obligations between contractual parties, (2) it's more comprehensive than the concept of legal contract, (3) it's an individual-level construct, (4) it changes over time, (5) it affects organizational behaviors, and (6) it's susceptible to organizational factors (Koh et al., 2004; Rousseau, 1996; Coyle-Shapiro, 2000). The aim of this paper is to put the concept, psychological contract commitment (PCC), under the spotlight, by finding out its mediating effects between legal contracts/partnerships and IS outsourcing success. Our interest is in the psychological contract commitment (PCC) or commitment to psychological contracts, which is the extent to which a partner consistently and deeply concerns with what the counter-party believes as obligations during the IS project. The basic premise for the hypothesized relationship between PCC and success is that for outsourcing success, client and vendor should continually commit to mutual obligations in which both parties believe, rather than to only explicit obligations. The psychological contract commitment playsa pivotal role in evaluating a counter-party because it reflects what one party really expects from the other. If one party consistently shows high commitment to psychological contracts, the other party would evaluate it positively. This will increase positive reciprocation efforts of the other party, thus leading to successful outsourcing outcomes (McNeeley and Meglino, 1994). We have used matched sample data for this research. We have collected three responses from each set of a client and a vendor firm: a project manager of the client firm, a project member from the vendor firm with whom the project manager cooperated, and an end-user of the client company who actually used the outsourced information systems. Special caution was given to the data collection process to avoid any bias in responses. We first sent three types of questionnaires (A, Band C) to each project manager of the client firm, asking him/her to answer the first type of questionnaires (A).

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.55-64
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• 2008

A detailed understanding and appreciation of the important mechanisms operating at the soil:root interface, commonly identified as the rhizosphere, is critical for evaluating the potential for particular plant species to be successfully used as part of a phytoremediation technique. For specific plants, mechanisms may exist to overcome the inherit limitation of the phytoremediation technique when poorly mobile soil metals are of interest. In the present study, the influence of root exudates on the rhizosphere chemistry of soil and consequential metal uptake were investigated following culture of vetiver grass (Vetiveria zizanioides), recognized as a promising plant for land stabilization, in three different long-term contaminated soils and one non-contaminated control soil. The soil solution pH increased (0.3-1.1 units) following vetiver grass culture and dissolved organic carbon (DOC) also significantly increased in all soils with the highest increase in PP02 (23 to $173mg\;L^{-1}$). Chemical changes are contributed to root exudation by vetiver grass when exposed to high concentration of heavy metals. Chemical changes, consequently, influenced metal (Cd, Cu, Pb, and Zn) solubility and speciation in the rhizosphere. The highest solubility was observed for soil Ko01 (eg. 2091 and $318{\mu}g\;L^{-1}$ for Cd and Pb, respectively). Initial heavy metal solubility in soils varied with soil and either increased or decreased following vetiver grass culture depending on the soil type. An increase in pH following plant culture generally resulted in a decrease in metal solubility, while elevated DOC due to root exudation resulted in an increase in metal solubility via the formation of metal-DOC complexes. Donnan speciation demonstrated a significant decrease in free Cd and Zn in the rhizosphere and the concentration of Cd, Pb, and Zn in vetiver grass shoot was highly correlated with soluble concentration rather than total soil metal concentration.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.73-77
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• 2012

Recently, Interest to the photoconductor, which is used to flat form X-ray detector such as a-Se, $HgI_2$, PbO, CdTe, $PbI_2$ etc. is increasing. In this study, the film layer by using the photoconductive material with particle sedimentation was fabricated and evaluated. The quantization efficiency of the continuous X-ray with the 70 kVp energy bandwidth was analyzed by using the Monte Carlo simulation. With the results, the thickness of film with 64 % quantization efficiency was 180 ${\mu}m$ which is similar to the efficiency of 500 ${\mu}m$ a-Se film. And $HIg_2$ film has the high quantization efficiency of 74 % on 240 ${\mu}m$ thickness. The electrical characteristics of the 239 ${\mu}m$ $Hgl_2$ films produced by particle sedimentation were shown as very low dark current(under 10 $pA/mm^2$), and high sensitivity(19.8 mC/mR-sec) with 1 $V/{\mu}m$ input voltage. The SNR, which is influence to the contrast of X-ray image, was shown highly as 3,125 in low driving voltage on 0.8 $V/{\mu}m$. With the results of this study, the development of the low-cost, high-performance image detector with film could be possible by replacing the film produced by particle sedimentation instead to a-Se detector.

• Journal of Science and Technology Studies
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• v.8 no.1
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• pp.97-129
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• 2008

We are living in the time of high probability of technological risk due to increased rate of technology development and diffusion of new technologies. Resolving uncertainties, the basic attribution of risk, by accumulating knowledge over the risk factors of certain technology is critical to management of technological risk. In many cases of technological risks, high uncertainty of knowledge is commonly mentioned reason for public controversies on risk management. However, the type of technological risk with low social agreement and low uncertainty of knowledge, the main reason for public controversy is absence of social agreement. Public debates on the risks of mobile phones electromagnetic fields(EMF) to human health comes under this category. The knowledge uncertainty on human health effect of mobile phones EMF has been lowered increasingly by accumulating enormous volume of knowledge though scientists have not reached a final conclusion whether it pose a risk to the physical and mental health of the general population or not. In contrast with civil organizations calling for precautionary approach based regulation, the mobile phone industry is cling to the position of no-regulation-needed by arguing no clear evidence to prove health risks of mobile phone EMF has found. In Korea, government set exposure standards based on a measurement called the 'specific absorption rate'(SAR) and require the mobile phone industry to open SAR information to the public by their own decision. From the view of pro-regulation side based on precautionary approach, technology risk managament of mobile phones EMF in Korea is highly limited and formalized one with limited measuring of SAR on head part only and problematic self-regulated opening of information about SAR to the public. As far as the government keeps having priority on protecting interest of mobile phone industry over precautionary regulation of mobile phones EMF, the disagreement between civil organizations and the government will not resolved. The risk of mobile phones EMF to human health have high probability of being underestimated in the rate and damage of risk than objectively estimated ones due to familiarity of mobile phone technology. And this can be the cause of destructive social dispute or devastating disaster. To prevent such disastrous results, technology risk management, which integrating the goals of safety with economic growth in public policy and designing and promoting risk communication, is required.

• KDI Journal of Economic Policy
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• v.31 no.1
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• pp.169-206
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• 2009

This study stems from a question, "How should we understand the pattern of the Korean economy after the 1990s?" Among various analytic methods applicable, this study chooses a Structural Vector Autoregression (SVAR) with long-run restrictions, identifies diverse impacts that gave rise to the current status of the Korean economy, and differentiates relative contributions of those impacts. To that end, SVAR is applied to four economic models; Blanchard and Quah (1989)'s 2-variable model, its 3-variable extensions, and the two other New Keynesian type linear models modified from Stock and Watson (2002). Especially, the latter two models are devised to reflect the recent transitions in the determination of foreign exchange rate (from a fixed rate regime to a flexible rate one) as well as the monetary policy rule (from aggregate targeting to inflation targeting). When organizing the assumed results in the form of impulse response and forecasting error variance decomposition, two common denominators are found as follows. First, changes in the rate of economic growth are mainly attributable to the impact on productivity, and such trend has grown strong since the 2000s, which indicates that Korea's economic growth since the 2000s has been closely associated with its potential growth rate. Second, the magnitude or consistency of impact responses tends to have subsided since the 2000s. Given Korea's high dependence on trade, it is possible that low interest rates, low inflation, steady growth, and the economic emergence of China as a world player have helped secure capital and demand for export and import, which therefore might reduced the impact of each sector on overall economic status. Despite the fact that a diverse mixture of models and impacts has been used for analysis, always two common findings are observed in the result. Therefore, it can be concluded that the decreased rate of economic growth of Korea since 2000 appears to be on the same track as the decrease in Korea's potential growth rate. The contents of this paper are constructed as follows: The second section observes the recent trend of the economic development of Korea and related Korean articles, which might help in clearly defining the scope and analytic methodology of this study. The third section provides an analysis model to be used in this study, which is Structural VAR as mentioned above. Variables used, estimation equations, and identification conditions of impacts are explained. The fourth section reports estimation results derived by the previously introduced model, and the fifth section concludes.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.26-39
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• 2016

This research paper explores the process of developing skateboarding spaces in urban parks. Skateboarding is one of the most popular sport activities representative of urban parks. This research paper will analyze the process of introducing skateboarding activities into park spaces and their acceptance by the general public as well as derive meaningful general implications for park space development planning. The research method is a discourse analysis of newspaper articles regarding skateboarding issued between the 1960s and 2010s. These articles are the main resources to show the creation of a skateboarding culture, generation of skate park spaces, and the extinction of these spaces during the research period. The result of this research is as follows. There are reasons that allowed for the creation of skate park spaces in urban parks. First of all, positive associations that people have regarding skateboarding have influenced the park's users and operators' decisions that a park is proper space for skateboarding activities, and the agreement to remodel the park space. Secondly, skate parks became a space for multiple-uses that can be shared with other emerging sports, which resulted in a building boom of skateboarding spaces in urban parks. Thirdly, urban parks and their new culture of active sports became a marketing tool used by local governments to attract new inhabitants to their new towns. On the contrary, there are three main reasons for the deterioration of skate parks. First of all, within parks in which skateboarding activities collided with other park usage, the skate parks disappeared. Secondly, skate parks built specifically for competitive skateboarding events and without consideration of casual skaters disappeared, as these facilities were not sustainable for use in the long term. Thirdly, the golden age of skate park skateboarding did not last long, as skateboarding trends shifted from trick performance to street skating, where skate parks are no longer needed. For this reasons, the exclusive use of park space for skateboarding activities has faded from public interest. The findings of this research suggest how sport activities should be introduced to urban parks. At first, each park's management needs to identify a sport suitable for long-term development, and not only plan for temporal events or follow fleeting trends. Secondly, the park's management systems should reflect a type of sport activity that would not only be popular at the beginning of the spaces development, but also take into consideration how these activities will change over time. Lastly, in cases where there are conflicts between sport activities and other activities in urban parks, attempts should be made to suggest feasible solutions other than the liquidation of sport spaces. This study explains the development process of sport spaces offered in urban parks, by thorough research of the process of acceptance of skateboarding activities in current urban park systems. This conclusion also indicates further areas for research with the purpose of understanding general best practices in urban parks sport space planning.

• Korean journal of food and cookery science
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• v.9 no.1
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• pp.1-6
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• 1993

The possession of microwave range, oven and oven-microwave range has been greatly increased with 88 Seoul Olympic Game as a momentum, and the possession rate was by 68%. The respondent answered the function of microwave range to be more necessary than that of oven, and the two household commodities have been mostly used to reheat and heat simply prepared frozen foods. The 35% among total respondent wished to cook the prepared frozen foods like pizza, but the 87% prefered to cook bakery. The frequencies of the use of oven were 35%, 35% for cooking premix and raw materials, and 20%, 20% for cooking half-prepared and prepared foods, respectively. The respondent of 39% was interested in premix foods as a future preference for food forms, and the respondent with interest in half-prepared food was 30%, but the preference for raw materials and prepared foods showed a trend to be decreased. The respondent of 60ft had eaten out six times week, and 50% had eaten instant and fast foods 1~3 times week. As the results of this survey, most of consumers prefer to more convenient foods. Therefore, it is expected that the function of oven and microwave range would be widely useful if various foods are improved with regards to convenience for use and preference.