• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4357-4366
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• 2023

MARS-KS, a domestic regulatory confirmatory code of Republic of Korea, had been developed by integrating RELAP5/MOD2 and COBRA-TF. The integration of COBRA-TF allowed to extend the capability of MARS-KS, limited to one-dimensional analysis, to multi-dimensional analysis. The use of COBRA-TF was mainly focused on subchannel analyses for simulating multi-dimensional behavior within the reactor core. However, this feature has been remained as a legacy without ongoing maintenance. Meanwhile, MARS-KS also includes its own multidimensional component, namely MULTID, which is also feasible to simulate three-dimensional convection and diffusion. The MULTID is capable of modeling the turbulent diffusion using simple mixing length model. The implementation of the turbulent mixing is of importance for analyzing the reactor core where a disturbing cross-sectional structure of rod bundle makes the flow perturbation and corresponding mixing stronger. In addition, the presence of this turbulent behavior allows the secondary transports with net mass exchange between subchannels. However, a series of assessments performed in previous studies revealed that the turbulence model of the MULTID could not simulate the aforementioned effective mixing occurred in the subchannel-scale problems. This is obvious consequence since the physical models of the MULTID neglect the effect of mass transport and thereby, it cannot model the void drift effect and resulting phasic distribution within a bundle. Thus, in this study, the turbulence mixing model of the MULTID has been improved by means of the inter-channel mixing model, widely utilized in subchannel analysis, in order to extend the application of the MULTID to small-scale problems. A series of assessments has been performed against rod bundle experiments, namely GE 3X3 and PSBT, to evaluate the performance of the introduced mixing model. The assessment results revealed that the application of the inter-channel mixing model allowed to enhance the prediction of the MULTID in subchannel scale problems. In addition, it was indicated that the code could not predict appropriate phasic distribution in the rod bundle without the model. Considering that the proper prediction of the phasic distribution is important when considering pin-based and/or assembly-based expressions of the reactor core, the results of this study clearly indicate that the inter-channel mixing model is required for analyzing the rod bundle, appropriately.

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.703-718
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• 2014

This study sought to investigate learning progressions for astronomical systems which synthesized the motion and structure of Earth, Earth-Moon system, solar system, and the universe. For this purpose we developed ordered multiple-choice items, applied them to elementary and middle school students, and provided validity evidence based on the consequence of assessment for interpretation of learning progressions. The study was conducted according to construct modeling approach. The results showed that the OMCs were appropriate for investigating learning progressions on astronomical systems, i.e., based on item fit analysis, students' responses to items were consistent with the measurement of Rasch model. Wright map analysis also represented that the assessment items were very effective in examining students' hypothetical pathways of development of understanding astronomical systems. At the lower anchor of the learning progression, while students perceived the change of location and direction of celestial bodies with only two-dimensional earth-based view, they failed to connect the locations of celestial bodies with Earth-Moon system model, and they could recognized simple patterns of planets in the solar system and milky way. At the intermediate levels, students interpreted celestial motion using the model of Earth rotation and revolution, Earth-Moon system, and solar system with space-based view, and they could also relate the elements of astronomical structures with the models. At the upper anchor, students showed the perspective change between space-based view and earth-based view, and applied it to celestial motion of astronomical systems, and they understood the correlation among sub-elements of astronomical systems and applied it to the system model.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.3
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• pp.329-352
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• 2017

Since the late 2000s Korean foreign direct investors in North Korea and China border regions have gone through the closure of outward processing trade(OPT) networks and changes in their location due to UN security council resolution and Korean independent sanctions against North Korea's nuclear and missile tests. However, the introduction of new Chinese OPT policy has led to the invigoration of domestic market-based OPT networks towards North Korea. The main aim of this paper is to identify the exceptional characteristics of Dandong in Liaoning province, a North Korea and China border region by analyzing OPT networks towards North Korea. Fundamentally the establishment of OPT networks towards North Korea is likely to be based on the utilization of a plenty of low wages in North Korea. The main reasons for this are fallen into two perspectives: geo-economics and geo-politics. The first perspective is geo-economics centering on the consolidation of economic exchange between North Korea and China, and North Korean economic development. For example, the introduction of Chinese OPT in border region has enabled Chinese local firms based on domestic market to access a plenty of low wage in North Korea in formal and institutional contexts. The second is geo-politics for the stability of North Korean regime based on the means of geo-economics. As the invigoration of domestic market-based OPT networks might make North Korea possible promoting foreign money earning, it enable North Korea to be sustainable as a buffering region between capitalist and socialist regime for China. It shows Chinese geo-strategic attempts to deal with the economic and regime stability of North Korean as a buffering state. In other words, OPT networks in North Korea should be concerned with the discourse practice of geo-economics and geo-politics which might lead to various and contingent spatial economies in border region. As a consequence, North Korea and China border regions could defined as a space in which is applicable to exceptional institutions and policies, and an exploitative space in which create surplus and rents by utilizing a plenty of low wages in North Korea through OPT networks.

• Asia pacific journal of information systems
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• v.21 no.4
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• pp.45-62
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• 2011

The notion of information systems (IS) continuance has recently emerged as one of the most important research issues in the field of IS. A great deal of research has been conducted thus far on the basis of theories adapted from various disciplines including consumer behaviors and social psychology, in addition to theories regarding information technology (IT) acceptance. This previous body of knowledge provides a robust research framework that can already account for the determination of IS continuance; however, this research points to other, thus-far-unelucidated determinant factors such as habit, which were not included in traditional IT acceptance frameworks, and also re-emphasizes the importance of emotion-related constructs such as satisfaction in addition to conscious intention with rational beliefs such as usefulness. Experiences should also be considered one of the most important factors determining the characteristics of information system (IS) continuance and the features distinct from those determining IS acceptance, because more experienced users may have more opportunities for IS use, which would allow them more frequent use than would be available to less experienced or non-experienced users. Interestingly, experience has dual features that may contradictorily influence IS use. On one hand, attitudes predicated on direct experience have been shown to predict behavior better than attitudes from indirect experience or without experience; as more information is available, direct experience may render IS use a more salient behavior, and may also make IS use more accessible via memory. Therefore, experience may serve to intensify the relationship between IS use and conscious intention with evaluations, On the other hand, experience may culminate in the formation of habits: greater experience may also imply more frequent performance of the behavior, which may lead to the formation of habits, Hence, like experience, users' activation of an IS may be more dependent on habit-that is, unconscious automatic use without deliberation regarding the IS-and less dependent on conscious intentions, Furthermore, experiences can provide basic information necessary for satisfaction with the use of a specific IS, thus spurring the formation of both conscious intentions and unconscious habits, Whereas IT adoption Is a one-time decision, IS continuance may be a series of users' decisions and evaluations based on satisfaction with IS use. Moreover. habits also cannot be formed without satisfaction, even when a behavior is carried out repeatedly. Thus, experiences also play a critical role in satisfaction, as satisfaction is the consequence of direct experiences of actual behaviors. In particular, emotional experiences such as enjoyment can become as influential on IS use as are utilitarian experiences such as usefulness; this is especially true in light of the modern increase in membership-based hedonic systems - including online games, web-based social network services (SNS), blogs, and portals-all of which attempt to provide users with self-fulfilling value. Therefore, in order to understand more clearly the role of experiences in IS continuance, analysis must be conducted under a research framework that includes intentions, habits, and satisfaction, as experience may not only have duration-based moderating effects on the relationship between both intention and habit and the activation of IS use, but may also have content-based positive effects on satisfaction. This is consistent with the basic assumptions regarding the determining factors in IS continuance as suggested by Oritz de Guinea and Markus: consciousness, emotion, and habit. The principal objective of this study was to explore and assess the effects of experiences in IS continuance, with special consideration given to conscious intentions and unconscious habits, as well as satisfaction. IN service of this goal, along with a review of the relevant literature regarding the effects of experiences and habit on continuous IS use, this study suggested a research model that represents the roles of experience: its moderating role in the relationships of IS continuance with both conscious intention and unconscious habit, and its antecedent role in the development of satisfaction. For the validation of this research model. Korean university student users of 'Cyworld', one of the most influential social network services in South Korea, were surveyed, and the data were analyzed via partial least square (PLS) analysis to assess the implications of this study. In result most hypotheses in our research model were statistically supported with the exception of one. Although one hypothesis was not supported, the study's findings provide us with some important implications. First the role of experience in IS continuance differs from its role in IS acceptance. Second, the use of IS was explained by the dynamic balance between habit and intention. Third, the importance of satisfaction was confirmed from the perspective of IS continuance with experience.

• Hwankyungkyoyuk
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• v.3 no.1
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• pp.55-62
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• 1992

In the orient, ancestor's perception to natural environment was related on the change of climate. Man had been a essence of the warm blood animal, which had suited in mild climate for living and acting. The weather of hot or cold was not only comfort in human life but influences negatively on human behavior. The most people of oriental was particularly interrelated to seasonal change of climate in earlier time. Because, there are elements such as temperature, humidity and wind in the category of climate, these elements differentiated seasonal change. The main methods of perception of natural environment were observed and classified. Although these methods were in the primitive stage, these coincided the tendency of modern science. For example, confucian was recognized the law of vertical air current that warm air rised and cold air sinked. And they could classify all elements nature based on the principles of 'Yin and Yang(陰陽論)' such as male and female, the sun and moon. shade and light etc. Thus results of the observation and the classification concerned with physical environment can be utilize a wisdom for progressive life of inhabitants. It was a origin of the education in natural environment. Commonness in the viewpoint of environment in the orient if recognized the law of circulation. Buddhism, originated in india, realized that all of phenomena in the world was changed slowly through the principles of cycle(輪廻說) such as male and female, the sun and moon, shade and light etc. Thus results of the observation and the classification concerned with physical environment can be utilized a wisdom for progressive life of inhabitants. It was a origin of the education in natural environment. Commonness in the viewpoint of environment in the orient if recognized the law of circulation. Buddhism, originated in India, realized that all of phenomena in the world was changed slowly through the principles of cycle(輪廻說). For example, whole of land is shifted from young stage to old stage as the life cycle of humanbeing. The theory of karma effects(葉報設) is so signify with the good result that good one's action is reap a sweet fruit. The most environmental problem in today must realized as a consequence of men's act. Then Taoism emphasized the pure nature without the artificiality. Because complexual environment was composed of several elements, It was maintained through the artificiality. Because complexual environment was composed of several elements, It was maintained through the interaction of cause and effects. The solution of environmental problem is maintenanced the harmony between cause and effects by a philosophical concept.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1069-1077
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• 2009

Lately, it is an important concern in water resources research to maintain a stable water supply according to a future climate change and an increase in water use. In Han-River basin, approximately 10 % of water resources that is provided the capital region (Gyeonggi, Seoul etc.) has been reduced as a consequence of the construction of Imnam Dam (storage volume: 27 billion $m^3$) located in the upper Hwacheon Dam upstream area. Therefore, streamflows have decreased in Bukhangang basin, but it could not be evaluated quantitatively. In this study, SWAT-K which is the physically based long-term runoff simulation model, was used in order to evaluate the effect of Imnam Dam on the reduced inflow to Hwacheon Dam according to the change of hydrological condition in the upstream area of Hwacheon Dam. For the model input data of North Korea area, meteorological data of GTS (Global Telecommunication System) were used, and soil maps by FAO/UNESCO (2003) were applied. Temporal variations of water resources is investigated with comparison of observed and simulated inflows at Hawcheon Dam site. Also, annual, monthly, seasonal decreases in water resources were evaluated using the flow duration analysis of simulated streamflows with or without Imnam dam.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1305-1313
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• 2006

Five male dairy goats (Saanen), 4.6 month old with a body weight of 21.4 ($SD{\pm}1.6$) kg, were used to examine 5 dietary urea treatments in a $5{\times}5$ Latin Square experimental design. The five levels of urea were 10, 20, 30, 40 and 50 g urea/kg DM of steam-treated oil palm fronds (OPF) and dry matter intake tended (p>0.05) to increase with increasing urea supplementation up to 30 g/kg OPF (77.7 g/kg $BW^{0.75}$), but decreased (p<0.05) with 40 and 50 g urea/kg OPF (67.4 and 63.7 g/kg BW0.75, respectively) supplementation. Similarly, dry matter, organic matter, crude protein, neutral detergent fiber and hemicellulose digestibilities increased (p<0.05) with the addition of urea to 30 g/kg OPF but thereafter decreased (p<0.05) with 40 and 50 g/kg OPF. Ruminal pH, ruminal $NH_3$-N concentration and plasma urea concentration increased linearly (p<0.01) and quadratically (p<0.01) as a consequence of addition of urea to the diet. Excretion of total purine derivatives (PD) by goats fed 30 g of urea/kg OPF was highest (p<0.05) followed by goats fed 20, 40, 10 and 50 g of urea/kg OPF. Microbial N (g N/day) and efficiency of microbial N supply expressed as g N/kg organic matter apparently digested in the rumen were higher (p<0.05) in goats fed 30 g of urea/kg OPF (5.5 g N/day and 22.0 g N/kg DOMR, respectively) than in goats on 10 and 50 g of urea/kg OPF treatments. However, the former did not differ from goats fed 20 g of urea/kg OPF (3.9 g N/day and 16.6 g N/kg DMOR, respectively). Ruminal VFA concentration, protein/energy ratio, N absorption and N retention increased (p<0.05) with the addition of urea to the diet up to 30 g/kg OPF but decreased (p<0.05) with 40 and 50 g/kg OPF. This implies that the optimal level of urea supplementation in an OPF based diet was about 30 g urea/kg OPF.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.1003-1010
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• 2008

The objective of the present study was to identify differences in the expression levels of liver proteins between healthy and ketotic cows, establish a liver metabolic interrelationship of ketosis and elucidate the metabolic characteristics of the liver during ketosis. Liver samples from 8 healthy multiparous Hostein cows and 8 ketotic cows were pooled by health status and the proteins were separated by two-dimensional-electrophoresis (2D-E). Statistical analysis of gels was performed using PDQuest software 8.0. The differences in the expression levels of liver proteins (p<0.05) between ketotic and healthy cows were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) tandem mass spectrometry. Five enzymes/proteins were identified as being differentially expressed in the livers of ketotic cows: expression of 3-hydroxyacyl-CoA dehydrogenase type-2 (HCDH), acetyl-coenzyme A acetyltransferase 2 (ACAT) and elongation factor Tu (EF-Tu) were down-regulated, whereas that of alpha-enolase and creatine kinase were up-regulated. On the basis of this evidence, it could be presumed that the decreased expression of HCDH, which is caused by high concentrations of acetyl-CoA in hepatic cells, in the livers of ketotic cows, implies reduced fatty acid ??oxidation. The resultant high concentrations of acetyl-CoA and acetoacetyl CoA would depress the level of ACAT and generate more ??hydroxybutyric acid; high concentrations of acetyl-CoA would also accelerate the Krebs Cycle and produce more ATP, which is stored as phosphocreatine, as a consequence of increased expression of creatine kinase. The low expression level of elongation factor Tu in the livers of ketotic cows indicates decreased levels of protein synthesis due to the limited availability of amino acids, because the most glucogenic amino acids sustain the glyconeogenesis pathway; thus increasing the level of alpha-enolase. Decreased protein synthesis also promotes the conversion of amino acids to oxaloacetate, which drives the Krebs Cycle under conditions of high levels of acetyl-CoA. It is concluded that the livers of ketotic cows possess high concentrations of acetyl-CoA, which through negative feedback inhibited fatty acid oxidation; show decreased fatty acid oxidation, ketogenesis and protein synthesis; and increased gluconeogenesis and energy production.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.15-19
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• 2007

This paper reports the effects of Ar ion beam surface treatment on a $SiO_2$ dielectric layer in organic thin film transistors. We compared the electrical properties of pentacene-based OTFTs, treated by $O_2$ plasma or Ar ion beam treatments and characterized the states of the surface of the dielectric by using atomic force microscopy and X-ray photoelectron spectroscopy. For the sample which received $O_2$ plasma treatment, the mobility increased significantly but the on/off current ratio was found very low. The Ar ion beam-treated sample showed a very high on/off current ratio as well as a moderately improved mobility. XPS data taken from the dielectric surfaces after each of treatments exhibit that the ratio of between Si-O bonds and O-Si-O bonds was much higher in the $O_2$ plasma treated surface than in the Ar ion beam treated surface. We believe that our surface treatment using an inert gas, Ar, carried out an effective surface cleaning while keeping surface damage very low, and also the improved device performances was achieved as a consequence of improved surface condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8776-8790
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• 2015

As a follow-up research of a qualitative study conducted by Lee(2015), this study needed to carry out a quantitative research targeting not a group of experts but of working-level staff and verify the validity of the assessment scales. As far as the study learned from an exploratory factor analysis of the preliminary research, these 12 questions that were incorrectly categorized or that presented outliers had to be removed and as a consequence, the researcher of the study was led to an outcome(75 Items) that would correspond to this factor structure which one had temporarily set up. For the next step, in order to carry out a confirmatory factor analysis, the study worked on verification on a four-stage structural equation model with each of the factors which the researcher had established applied by stage. In the end, a result to confirm how the model's goodness of fit eventually increases with the factors which the researcher had set up added was gained and lastly, another outcome to agree to the hair designers' expertise practice model which the researcher had created was obtained. In the meantime, in terms of the assessment scales which this study has discussed, the study assumes that since the scales accepted a self-rating method, it may lead not only to increase in expertise through self-reflection but also to establishment of a rational class system based on results of objective expertise measuring but not of subjective judgment by superiors.