• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.162-168
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• 2000

The influence of phenolsulfunate concentrations on electroplating characteristics and electrochemical behaviors was investigated with a viewpoint of electrolyte aging using the circulation cell and potentiostate And comparison of tinplate coating appearance such as glossiness and Image clarify has been also studied with varying of phenolsulfonic acid (PSA) solutions. As the aging of electrolyte proceeded, the limiting current density was moved to a lower current density region by the limitation of mass transfer, and higher phenolsulfunate concentrations resulted in the narrower optimum current density range and deterioration of coating surface of tinplates. The difference of the limiting current density was not remarkable with increasing electrolyte temperature. Thus the electrolyte aging was attributed to the limitation of thermally-activated process such as mass transfer of reducible ions. It has also been considered that the accumulation of phenolsulfonate suppressed normal electrotinning reaction by reducing the mobility of stannous ions, taking into account of the smaller effect of electrolyte aging. Experiments showed similar polarization behavior between the electrolyte of high phenolsufonate solution and the aged one, which comes to conclude that the accumulation of phenolsulfonate is one of the major causes of electrolyte aging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.608-615
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• 2017

The objective of this study was to evaluate the physicochemical, structural, and rheological properties of new domestic potato cultivars ('Goun', 'Sebong', and 'Jinsun') against the foreign potato cultivar 'Atlantic'. Based on the results obtained from scanning electron micrograph, X-ray, and Fourier transform infrared spectrum analyses, the structural properties of all potato flours were not considerably different. Rapid visco analyzer analyses showed that the setback viscosities of 'Goun', 'Sebong', and 'Jinsun' were significantly lower than that of 'Atlantic'. For steady shear rheological properties, potato flour dispersions showed shear-thinning behaviors (n=0.45~0.49) at $25^{\circ}C$. Apparent viscosity and consistency index of 'Atlantic' were similar to those of 'Sebong' and 'Jinsun'. For dynamic shear rheological properties, storage modulus (G′) and loss modulus increased, whereas complex viscosity (${\eta}^*$) was reduced with increasing frequency from 0.63 to 62.8 rad/s. G′ and ${\eta}^*$ values of 'Jinsun' were significantly higher than those of the other potato cultivars.

• Resources Recycling
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• v.11 no.6
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• pp.38-46
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• 2002

Fundamental investigations were conducted far the recovery process of waste organic solvent by fractional distillation in the aspects of equilibrium and kinetics. Mixture of toluene and xylene, which were both being used in the largest amount as industrial organic solvent, was taken as the artificial waste organic solvent and their distillation behaviors were studied. The purity of recovered solvent was investigated by Cir Chromatography and shown to be in the range of 94～98%. Based upon equilibrium calculations, the changes in the Gibbs free energy, standard enthalpy, and standard entropy for distillation reaction have been estimated. The standard enthalpy changes for toluene and xylene were shown to be 44.833 and 47.044 kJ $mol^{-1}$ respectively, which were similar to their molar heats of evaporation. The activation energies of distillation fur toluene and xylene obtained from kinetic studies were 3.281 and 2.699 kJ $mol^{-1}$ and they were about one tenths of the standard enthalpy changes of distillation reaction. The highness of the purity of recovered organic solvents suggested the possibility that the recovered waste organic sol-vent could partly replace the original solvent.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.1-14
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• 2007

Optimal design method of nonlinear damping system for seismic response control of adjacent structures is studied in this paper. The objective functions of the optimal design are defined by structural response and total amount of the dampers. In order to obtain a solution minimizing two mutually conflicting objective functions simultaneously, multi-objective optimization technique based on genetic algorithm is adopted. In addition, stochastic linearization method is embedded into the multi-objective framework to efficiently estimate the seismic responses of the adjacent structures interconnected by nonlinear hysteretic dampers without performing nonlinear time-history analyses. As a numerical example to demonstrate the effectiveness of the proposed technique, 20-story and 10-story buildings are considered and MR dampers of which hysteretic behaviors vary with the magnitude of the input voltage are considered as nonlinear hysteretic damper interconnecting two adjacent buildings. The proposed approach can provide the optimal number and capacities of the MR dampers, which turned out to be more economical than the uniform distribution system while maintaining similar control performance. The proposed damper system is verified to show more stable performance in terms of the pounding probability between two adjacent buildings. The applicability of the proposed method to the design problem for optimally placing semi-active control system is examined as well.

• Journal of the Ergonomics Society of Korea
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• v.28 no.1
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• pp.37-51
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• 2009

The nuclear power industry in the world has recognized the importance of integrating non-technical and team skills training with the technical training given to its control room operators to reduce human errors since the Three Mile Island and Chernobyl accidents. The Nuclear power plant (NPP) industry in Korea has been also making efforts to reduce the human errors which largely have contributed to 120 nuclear reactor trips from the year 2001 to 2006. The Crew Resource Management (CRM) training was one of the efforts to reduce the human errors in the nuclear power industry. The CRM was developed as a response to new insights into the causes of aircraft accidents which followed from the introduction of flight recorders and cockpit voice recorders into modern jet aircraft. The CRM first became widely used in the commercial airline industry, but military aviation, shipboard crews, medical and surgical teams, offshore oil crews, and other high-consequence, high-risk, time-critical industry teams soon followed. This study aims to develop a CRM training program that helps to improve plant performance by reducing the number of reactor trips caused by the operators' errors in Korean NPP. The program is; firstly, based on the work we conducted to develop a human factors training from the applications to the Nuclear Power Plant; secondly, based on a number of guidelines from the current practicable literature; thirdly, focused on team skills, such as leadership, situational awareness, teamwork, and communication, which have been widely known to be critical for improving the operational performance and reducing human errors in Korean NPPs; lastly, similar to the event-based training approach that many researchers have applied in other domains: aircraft, medical operations, railroads, and offshore oilrigs. We conducted an experiment to test effectiveness of the CRM training program in a condition of simulated control room also. We found that the program made the operators' attitudes and behaviors be improved positively from the experimental results. The more implications of the finding were discussed further in detail.

• Journal of the Korean Society of Costume
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• v.57 no.7
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• pp.30-44
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• 2007

The culture includes every possible objective forms created by humans and their shared aspects of ideas, feelings, and behaviors, beliefs and etc. The dress and its ornaments are part of the culture that expresses the relationships in objective ways and in formless immaterial ways. The school uniform represents significant meanings to the students in their school years, and it is the way of expressing their individuality and full filling their needs for self-presentation. Therefore, understanding and analyzing youth culture means understanding students' school uniform along with fast changing twenty first century civilization. Korea and Japan are very close nations to each other. Both Korean and Japanese girls' school uniform style were adopted western clothing style and went through many changes based on cultural differences between two countries. They are affected by different peculiarities between two nations and youth cultures from different cities. Therefore, this research is on analyzing how different visual values of girl's high school uniforms in Seoul and Tokyo and understanding youth cultures through macro-analysis. The youth cultures in Korea and Japan are mostly similar but there is special development on animation in Japan and possibly can find many styles of girl's high school uniform. Both nations are varying to be opened to sexual culture of adolescents but Japan is more uninhibited than Korea. In Japan, sailor-uniform can be found in fetish way in public culture. On one hand, because of most private girl's high schools in Tokyo takes an entrance examination, top-ranking students are very proud of their school uniforms and even students from other public high schools get private high school uniforms to attend school festival. This analysis showed that private girl's high school uniform in Seoul appealed as slim fitted silhouette which is close to modem woman's suit style while in Tokyo appealed as boxy style matched with short pleated skirt or sailor-uniform style. Comparing that to school uniform photos taken on the street, we can find that alikeness or more extreme styles as examples. These are influenced by different youth cultures in Seoul and Tokyo and cultural differences stands for different aesthetic norm being accepted or rejected.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.786-790
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• 2016

This paper discusses numerically explored orientation effects on the thermal performance of hollow hybrid fin heat sinks (HHFHSs) under natural convection. A HHFHS consists of an array of hollow pin fins concatenated with plate fins and having perforations near the fin bases. Orientation effects on the footprint-based and mass-based thermal performance of the HHFHS were numerically studied for orientation angles ranging from $0^{\circ}$ to $180^{\circ}$. The performance of the HHFHS was compared with that of a pin fin heat sink (PFHS) having similar physical parameters. The results show that the thermal resistance of the HHFHS did not vary considerably from $0^{\circ}$ to $45^{\circ}$. The thermal resistance increased from $45^{\circ}$ to $90^{\circ}$, reached its maximum at $90^{\circ}$, and decreased consistently from $90^{\circ}$ to $180^{\circ}$. Dissimilar behaviors of the thermal resistance of the HHFHS vs. the PFHS resulted mainly from the effect of heat pumping induced by the internal flows of the hollow fins. Despite various orientations, the mass-based thermal resistance of the HHFHS was found to be nearly 30% smaller than that of the PFHS. This result shows the feasibility of the HHFHS for the lightweight thermal management of electronics under natural convection.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.10
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• pp.771-782
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• 1991

In industrial multivariable plants, it is ofte the case that the plant outputs are measured in similar components not simultaneously but serially. In this paper, the problem of estimating the state vector of the plant based on the data obtained from such a measuring scheme is considered, and a special type of observer(referred to as a $'$multiple serial-sampling$'$ type observer) which renews its internal states whenever a new group of data is obtained is proposed. It is proved that such an observer can be constructed for almost every sampling period if the palnt is observable as a continuous-time multivariable system, and that the poles of the closed-loop system using the multiple serial-sampling type observer consist of the poles of the observer and those of the state feedback system. The behaviors of the observer and the closed-loop system are studied by simulation. The results of simulation indicate that a multiple serial-ampling type observer can estimate the state of the plant more accurately than the ordinary type observers and improve the closed-loop performance, especially, in the existence of measuring noise.ng noise.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.289-303
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• 2007

This report includes basic data on nutrition education for Chinese adolescents living in Korea. A total of 183 Chinese adolescents living in Incheon participated in the survey. Body composition was analyzed by the Inbody 4.0., and questionnaires on personal dietary behavior were administrated. When compared with the body measure indices of Korean adolescents, we found that height was similar, but weight greater ($5{\sim}12 kg$) among the participants. Regarding obesity, 30.0% of all students were obese (BMI>25), especially the high school boys (42.0%). But in the case of middle school boys, the rates of obesity and under weight (BMI<18.5) were the same (both of them at 22.9%). The average WHR (Waist Hip Ratio) of the female high school group (0.9) was over the normal range. The average percent body fat for each group was also over the normal range. The percentage of students having breakfast everyday was 52.2%, and the rate of skipping breakfast was 25.0%. In the obesity group, the rate of skipping breakfast was remarkably high (P<0.05). Because lunch service was not available at the schools, a lunch box from home was the most popular pattern (43.1 %), but eating out was also popular at 36.6%. For the male high school students, the eating out rate was 62.8%. Since many have-lived in Korea for a few generations, the students' eating practices were much closer to the Korean pattern. For their ordinary meal pattern, 96.0% of the students included Korean foods. however, for New Years Day, the rate of having Gyo-Ja was 75.2%, and having Wol-Byung at Choo-seok was 78.6%, showing that the Chinese tradition still remains. In the case of food preferences, the percentage having Kimchi everyday was 62.1 %, but those drinking green tea was 13.1 %. For cold drinks, the rate for drinking them more than twice per week was 71.6%. The most preferred cooking method was frying with oil (50.6%). Among the students who had visited China (or Taiwan), the rate for 'bad food familiarity' was 37.0%, and the rate for 'did not know Chinese traditional course menus' was 71.3%. As a result of combining eating practices from both China and Korea, and the absence of lunch service in Chinese schools, students are showing bad dietary behaviors. therefore, it is necessary to provide proper nutrition education and a system for lunch service in Chinese schools.

• Korean Journal of Community Nutrition
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• v.14 no.1
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• pp.22-30
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• 2009

This study aimed to examine nutritional status and similarities of diets between Vietnamese female immigrants and Korean spouses and dietary changes of Vietnamese females after immigration. Subjects were 608 couples visiting 13 medical centers for the Cohort of Intermarried Women in Korea from November 2006 to November 2007. Anthropometric and biochemical measurements were obtained and dietary intakes were assessed using one-day 24-hour recall. Sixty-eight percent of wives answered there have been changes in their diets and consumptions of meats, fish, dairy products, vegetables, and fruits increased after immigration. Energy intakes of wives and spouses were 1491.7 kcal and 1788.8 kcal, respectively, showing most couples (80.1%) consumed less than the Korean estimated energy requirements. More than half of the couples were below the Korean estimated average requirements of zinc, vitamin $B_2$, and folate. The correlation coefficients between couples ranged 0.15-0.38 for unadjusted, 0.22-0.35 for per 1000 kcal, and 0.21-0.40 for energy-adjusted, respectively. The proportions of couples in the same quartiles of each nutrient intake and in the same answers of each question of Mini Dietary Assessment were about 30% across nutrients and around 50% across questions. The length of residence is related to similarities of nutrient intakes between couples: similarities decreased after 3 years of residence in Korea. In conclusion, nutritional intakes of inter-married couples were inadequate although wives reported that their dietary intakes increased after immigration. Inadequate nutrient intakes of wives were partly explained by similar diets between couples because these wives without enough adjustment to Korean culture were more likely to follow what their spouses ate. Findings from this study may be helpful to improve the nutritional status of inter-married couples and make policies and programs for them. A follow-up study should identify factors affecting inadequate nutritional status of intermarried couples and similarities of their diets.