• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2367-2375
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• 2022

In this work, we propose a new mechanistic model for the treatment of helium behaviour at the grain boundaries in oxide nuclear fuel. The model provides a rate-theory description of helium inter-granular behaviour, considering diffusion towards grain edges, trapping in lenticular bubbles, and thermal resolution. It is paired with a rate-theory description of helium intra-granular behaviour that includes diffusion towards grain boundaries, trapping in spherical bubbles, and thermal re-solution. The proposed model has been implemented in the meso-scale software designed for coupling with fuel performance codes SCIANTIX. It is validated against thermal desorption experiments performed on doped UO₂ samples annealed at different temperatures. The overall agreement of the new model with the experimental data is improved, both in terms of integral helium release and of the helium release rate. By considering the contribution of helium at the grain boundaries in the new model, it is possible to represent the kinetics of helium release rate at high temperature. Given the uncertainties involved in the initial conditions for the inter-granular part of the model and the uncertainties associated to some model parameters for which limited lower-length scale information is available, such as the helium diffusivity at the grain boundaries, the results are complemented by a dedicated uncertainty analysis. This assessment demonstrates that the initial conditions, chosen in a reasonable range, have limited impact on the results, and confirms that it is possible to achieve satisfying results using sound values for the uncertain physical parameters.

• Journal of Welding and Joining
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• v.32 no.1
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• pp.28-33
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• 2014

In this paper, I-butt welding with 6mm thickness using Plasma-GMA welding was carried out. And weld characteristics of the Al-5083 aluminium alloy for Plasma-GMA hybrid welding was evaluated. The orthogonal experimental design was used to investigate the influence of plasma-MIG welding parameters such as plasma current, wire feeding rate, MIG-welding voltage and welding speed on the weld bead geometry and tensile strength using the ANOVA(Analysis of Variation). Then we conducted evaluation of contribution for process parameters. ANOVA results show that bead dimensions are affected by wire feeding speed, welding voltage and welding speed and tensile strength is mainly affected by welding speed and plasma arc current. Tensile strength was decreased by rise in plasma welding current because GMA welding current was decreased by plasma arc.

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.1
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• pp.29-38
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• 2008

Print-through is one of the most important attributes of print quality and has long been a subject to study. However, some aspects of print through are still in need to be enlighten. In this paper, different kinds of evaluating methods for print through are compared using densitometry, brightness, and image analysis. Printing conditions including ink feed, drying condition, and emulsification rate are systematically changed to effect print-through both on uncoated and coated commercial papers. Also several inks from different makers are introduced and compared in terms of print-through propensity. From the results, densitometry is not a good indicator for print through on the papers in this study. Ink feed has a strong effect on print through, especially for uncoated paper and should be considered in a point of optimum ink feed level in real world. Contribution of faster ink(oil) absorption seems to be more competitive than that of ink(oil) evaporation resulting in severer print-through for hot drying process. It is shown that ink-water emulsification rate increases print through at mild level but easy to decrease it with lower density due to the increase of water contents in emulsion. It is believed that the effect of absorption overwhelms that of density drop at mild emulsification level. This study does not include the effect of ink attributes in detail but shows that distinctive differences in print through may be resulted from various ink-makers and is finalized with some suggestions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.289-299
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• 2016

Weapon systems require reliability in the development phase for efficient combat readiness. Improved reliability in various manufacturing processes have been achieved using data analysis. However, data analysis in the development phase is difficult due to problems such as the lack of data, high cost, and the importance of security. Therefore, Post Logistics Support (PLS) data collected following integration is analyzed for long-term quality improvement of weapon systems. In this study, we propose a methodology for examining the correlation between the failure rate and PLS data as follows: First, key variables affecting reliability were identified the correlation between variables on the failure rate examined. Second, corresponding analysis was conducted for determining the correlation between patterns of categorical data. Third, extract categories with the higher contribution and quality of representation, and find the highest variable correlated with failure period through visualization. Then, after selecting patterns which have shorter failure period, the cause of decreased reliability was confirmed through frequency analysis. This study will contribute to improving reliability when developing new weapon systems and will help to strengthen the combat readiness of military.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.347-355
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• 2006

A study was conducted to predict the rumen microbial protein production based on urinary excretion of purine derivatives in buffaloes fed a diet of wheat straw and concentrate (40:60) at four fixed levels of feed intake. (95, 80, 60 and 40% of preliminary voluntary feed intake) following experimental protocol of IAEA (Phase I). The buffaloes were allocated according to a $4{\times}4$ latin square design. The urinary allantoin, uric acid, total PD excretion (mmol/d) in treatments L-95, L-80, L-60 and L-40 was 20.13, 16.00, 12.96 and 9.17; 1.88, 2.12, 2.11 and 2.15; 22.01, 18.12, 15.07 and 11.32, respectively and were significantly (p<0.05) different among treatments except for uric acid. The rate of PD excretion (mmol/d) was positively correlated with the digestible organic matter intake. Variations were observed in PD and creatinine concentration in spot samples collected at 6-hour interval. However, daily PD:Creatinine ratio (PDC index) appears to be a reasonably good predictor of microbial-N supply. The contribution of basal purine excretion to total excretion of purine derivatives (PD) was determined in pre-fasting period followed by a fasting period of 6 d (Phase II). Daily PD and creatinine excretion (mmol/kg $W^{0.75}$) during fasting averaged 0.117 and 0.456 respectively for buffaloes. The excretion rates of PD decreased significantly (p<0.01) during fasting compare to pre-fasting period, the urinary creatinine excretion remained almost similar. Except for creatinine, plasma concentration of target parameters significantly (p<0.01) declined during fasting. Likewise, glomerular filtration rate (GFR) and renal clearance of allantoin and uric acid also decreased. Based on the PD excretion rates during fasting and at different levels of feed intake obtained in this study, a relationship between daily urinary PD excretion (Y-mmol) and microbial purine absorption (X-mmol) was developed for buffaloes as Y = 0.74X+0.117 kg $W^{0.75}$. The microbial N supply (g/kg DOMI) remained statistically similar irrespective of dietary treatment. The results showed that excretion of urinary purine derivatives is positively correlated with the levels of feed intake in Murrah buffaloes and thus, estimation of urinary purine derivatives and PDC index could be used to determine microbial nitrogen supply when there is large variation in level of feed intake.

• Journal of Biomedical Engineering Research
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• v.36 no.1
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• pp.1-6
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• 2015

This study aims to design a monolayer cell adsorption apparatus that would help to produce high-quality slides for Liquid-Based Cytology (LBC) of an early cancer diagnosis for human bodies. The LBC collects exfoliated cells of human bodies and spreads the cells on the slides. Through processes of dyeing and cytological examination, the LBC screens for cancers in early stage. In this study, both of a cell suction module and a cell adsorption module, which are the key elements of the monolayer cell adsorption apparatus, were developed, and using those modules, the study set, first, conditions to help both GYN and NON-GYN apply principal cells without de-endothelialization before conducting its own analysis on the utility. As a results, for GYN, apparatus was determined to be able to produce high-quality slides under the condition of 4 and for NON-GYN, the apparatus would come up with other slides of high-quality under the condition of 2. The study carried out a repetitive test on selected conditions and proved 96% of the repetitive success rate. By the results of what has been learned so far, the study presents that the apparatus has a possibility to replace device from South Korea as one of those other currently-applied systems to run the LBC and that the system will also present a new paradigm for cancer diagnosis as it makes a contribution to the improvement in the LBC.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.175-187
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• 1999

The notion of productivity has been extended from the quantitative change of input factors to the efficiency change meaning efficient use of resources, and to the technical change meaning the qualitative improvement of input resources. In this way, the technical change is termed as total factor productivity in the individual businesses or the manufacturing industries. They should efficiently respond to the variations of economic environment and at the same time, have to make the efforts to improve productivity by increasing managerial efficiency and rasing the level of technology change for the continuous growth. Considering the growing importance of productivity, this study closely examines the factors influctuation on the productivity, fluctuation using total factor productivity in korean manufacturing industries. For the objective this study investigates the methods of measurement about total factor productivity, establishes the hypotheses based on the preceding research and finding. The results are obtained through the examination on the outcoms of regression analysis and related data. The results can be summarized as follows, First, in the progress of korean industrialization, the qualitative growth does not depend on the total factor productivity of the technical advance, and does not lead to the industry expansion. That is, the contribution of total factor productivity turns out to be relatively low. Second, it is necessary for the manufacturing industry to improve the level of technology and to emphasize the innovation of business, since the capital investment does not completely become fixed in the growth rate of productivity. Finally, continuous R&D investment should be made to increase total factor productivity. Namely, the regulation of industrial structure with an intensive technical development is essential and should be based on scientific and technical knowledge.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.2
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• pp.99-105
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• 1974

According to the content of sugar and starch of each positional leaf sheath and internode at heading and 4 weeks after it using IR667-Suwon 214 (high yielding var. having tropical Indica parantage) and Jinheung (local leading var. temperate Japonica) rice grown in various cultivation seasons the suitability of grouping into the high sugar type (sugar>starch), sugar, tendency (increasing tendency in sugar content), high starh type (starch>sugar) and starch tendency (increasing tendency in starch) in carbohydrate metabolism was reexamined as follows. 1. Sugar tendency appeared strongly in IR667 than Jinheung, internode than leaf sheath, late season cultivation than early season, 4 weeks after than heading and high temperature than low temperature. Thus at heading, leaf sheath and internode of Jinheung in early and late season cultivation were high starch type, and lower internode in early season cultiattion and leaf sheath and internode in late season for IR667 were high sugar type. In very late season all internodes of both varieties except 1st internode of Jinheung at heading were high starch type. At four week after heading all leaf sheaths except 1st and 4th one of Jinheung and all internodes were high sugar type. High sugar type was intensified 4 weeks after heading in leaf sheaths than in internodes of IR667 in early season and of both varieties in late season. 2. The upper three leaf sheaths and internodes seem to work in the same way for carbohydrate translocation. Among them upper ones showed sugar tendency at heading and starch tendency 4 weeks after heading and it was clear in Jinheung. 3. The later the cultivation season, the higher the carbohydrate content (sugar+starch), and such tendency was clear 4 weeks after heading and in IR667, suggesting teanslocation inhibition by low temperature. 4. Grain filling rate (weight increase per day) was more rapid in early season cultivation and IR667 took shorter days to reach maximum rate. 5. The later the cultivation season, the greater the percent contribution of carbohydrate before heading to yield and it was always greater in IR667, a leaf sheath type. 6. Sugar and starch ratio appears to be determined principally by metabolic characteristics of variety according to growth process and secondly but considerably by environmental factors.

• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.53-69
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• 2011

Vision and voice-based technologies are commonly utilized for human-robot interaction. But it is widely recognized that the performance of vision and voice-based interaction systems is deteriorated by a large margin in the real-world situations due to environmental and user variances. Human users need to be very cooperative to get reasonable performance, which significantly limits the usability of the vision and voice-based human-robot interaction technologies. As a result, touch screens are still the major medium of human-robot interaction for the real-world applications. To empower the usability of robots for various services, alternative interaction technologies should be developed to complement the problems of vision and voice-based technologies. In this paper, we propose the use of accelerometer-based gesture interface as one of the alternative technologies, because accelerometers are effective in detecting the movements of human body, while their performance is not limited by environmental contexts such as lighting conditions or camera's field-of-view. Moreover, accelerometers are widely available nowadays in many mobile devices. We tackle the problem of classifying acceleration signal patterns of 26 English alphabets, which is one of the essential repertoires for the realization of education services based on robots. Recognizing 26 English handwriting patterns based on accelerometers is a very difficult task to take over because of its large scale of pattern classes and the complexity of each pattern. The most difficult problem that has been undertaken which is similar to our problem was recognizing acceleration signal patterns of 10 handwritten digits. Most previous studies dealt with pattern sets of 8~10 simple and easily distinguishable gestures that are useful for controlling home appliances, computer applications, robots etc. Good features are essential for the success of pattern recognition. To promote the discriminative power upon complex English alphabet patterns, we extracted 'motion trajectories' out of input acceleration signal and used them as the main feature. Investigative experiments showed that classifiers based on trajectory performed 3%~5% better than those with raw features e.g. acceleration signal itself or statistical figures. To minimize the distortion of trajectories, we applied a simple but effective set of smoothing filters and band-pass filters. It is well known that acceleration patterns for the same gesture is very different among different performers. To tackle the problem, online incremental learning is applied for our system to make it adaptive to the users' distinctive motion properties. Our system is based on instance-based learning (IBL) where each training sample is memorized as a reference pattern. Brute-force incremental learning in IBL continuously accumulates reference patterns, which is a problem because it not only slows down the classification but also downgrades the recall performance. Regarding the latter phenomenon, we observed a tendency that as the number of reference patterns grows, some reference patterns contribute more to the false positive classification. Thus, we devised an algorithm for optimizing the reference pattern set based on the positive and negative contribution of each reference pattern. The algorithm is performed periodically to remove reference patterns that have a very low positive contribution or a high negative contribution. Experiments were performed on 6500 gesture patterns collected from 50 adults of 30~50 years old. Each alphabet was performed 5 times per participant using $Nintendo{(R)}$ $Wii^{TM}$ remote. Acceleration signal was sampled in 100hz on 3 axes. Mean recall rate for all the alphabets was 95.48%. Some alphabets recorded very low recall rate and exhibited very high pairwise confusion rate. Major confusion pairs are D(88%) and P(74%), I(81%) and U(75%), N(88%) and W(100%). Though W was recalled perfectly, it contributed much to the false positive classification of N. By comparison with major previous results from VTT (96% for 8 control gestures), CMU (97% for 10 control gestures) and Samsung Electronics(97% for 10 digits and a control gesture), we could find that the performance of our system is superior regarding the number of pattern classes and the complexity of patterns. Using our gesture interaction system, we conducted 2 case studies of robot-based edutainment services. The services were implemented on various robot platforms and mobile devices including $iPhone^{TM}$. The participating children exhibited improved concentration and active reaction on the service with our gesture interface. To prove the effectiveness of our gesture interface, a test was taken by the children after experiencing an English teaching service. The test result showed that those who played with the gesture interface-based robot content marked 10% better score than those with conventional teaching. We conclude that the accelerometer-based gesture interface is a promising technology for flourishing real-world robot-based services and content by complementing the limits of today's conventional interfaces e.g. touch screen, vision and voice.

• Journal of Intelligence and Information Systems
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• v.27 no.4
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• pp.23-48
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• 2021

The Korean economy has achieved continuous economic growth for the past several decades thanks to the government's export strategy policy. This increase in exports is playing a leading role in driving Korea's economic growth by improving economic efficiency, creating jobs, and promoting technology development. Traditionally, the main factors affecting Korea's exports can be found from two perspectives: economic factors and industrial structural factors. First, economic factors are related to exchange rates and global economic fluctuations. The impact of the exchange rate on Korea's exports depends on the exchange rate level and exchange rate volatility. Global economic fluctuations affect global import demand, which is an absolute factor influencing Korea's exports. Second, industrial structural factors are unique characteristics that occur depending on industries or products, such as slow international division of labor, increased domestic substitution of certain imported goods by China, and changes in overseas production patterns of major export industries. Looking at the most recent studies related to global exchanges, several literatures show the importance of cultural aspects as well as economic and industrial structural factors. Therefore, this study attempted to develop a forecasting model by considering cultural factors along with economic and industrial structural factors in calculating the import volume of each country from Korea. In particular, this study approaches the influence of cultural factors on imports of Korean products from the perspective of PUSH-PULL framework. The PUSH dimension is a perspective that Korea develops and actively promotes its own brand and can be defined as the degree of interest in each country for Korean brands represented by K-POP, K-FOOD, and K-CULTURE. In addition, the PULL dimension is a perspective centered on the cultural and psychological characteristics of the people of each country. This can be defined as how much they are inclined to accept Korean Flow as each country's cultural code represented by the country's governance system, masculinity, risk avoidance, and short-term/long-term orientation. The unique feature of this study is that the proposed final prediction model can be selected based on Design Principles. The design principles we presented are as follows. 1) A model was developed to reflect interest in Korea and cultural characteristics through newly added data sources. 2) It was designed in a practical and convenient way so that the forecast value can be immediately recalled by inputting changes in economic factors, item code and country code. 3) In order to derive theoretically meaningful results, an algorithm was selected that can interpret the relationship between the input and the target variable. This study can suggest meaningful implications from the technical, economic and policy aspects, and is expected to make a meaningful contribution to the export support strategies of small and medium-sized enterprises by using the import forecasting model.