• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.395-406
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• 2023

The first technological advance to improve the output and efficiency of the latest steam turbines operating in co-generation plants in Korea can be said to be progress in the field of materials that can use high-temperature, high-pressures steam. As a result of design efforts to improve the internal efficiency of steam turbines along with the development of materials, only a few manufacturers of steam turbine have produced high efficiency steam turbines. The internal efficiency of a steam turbine on the steam path operating for a long period of time is gradually lost owing to the limit of mechanical life, and efficiency and output decrease. Therefore, this study aims to develop a model that can analyze the steam flow path performance of HP (High Pressure) and IP (Intermediate Pressure) steam turbine for a co-generation plant using a commercial program and propose a performance calculation method. Owing to the complex performance calculation method of steam turbines, major variables are presented to serve as practically useful references for steam turbine practitioners. In addition, the thermal dynamic analysis(such as heat balance diagram calculation) and the the thermal dynamic calculation required for steam turbine performance calculation and the suitability of the steam turbine performance calculation results were compared with the performance test results.

• The Korean Journal of Woman Psychology
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• v.16 no.3
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• pp.303-329
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• 2011

In Korea, recent women's educational standard is more higher than any other period but rate of using human resources is the lowest level among the OECD nations. As the reason of this phenomenon, the career choice attract attention. Traditionally, job is classified female-dominated job from male-dominated job, and most women still avoid male-dominated job. If this unequal concentrated phenomenon is relieved, diversity using of human resource will be available. For the purpose, this study try to determine the experience structure and the career decision-making process of the female undergraduate who want the male-dominated job through the qualitative study method, and to determine factors that work negative or positive on the process to use for the career consult. Grounded theory based data analyses resulted in 61 concepts, 27 sub-categories, and 12 categories from the recorded data of 8 female undergraduates who want the male-dominated job. The core category was "For the special life, keeping challenging with the will". A paradigm model consist of the casual condition, central phenomenon, contextual condition, intervening condition, actions/reactions and the result was proposed. And the participants went through five stages with time in their career decision-making process: the stage of awareness about the trait and aspiration, the stage of internal determination, the stage of support and accept, the stage of challenge and overcome, and the stage of affirmation and confidence. Implications of the findings and suggestions for the future research are discussed.

• Anxiety and mood
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• v.18 no.2
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• pp.56-64
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• 2022

Objective : Creating a psychologically stable indoor environment is a significant factor in modern life. This study was conducted to confirm which type of wood interior decorating environment was beneficial for improving depression and anxiety. Methods : A total of 59 participants will randomly assign to each accommodation by dividing the rest of the three setting with the same structure with 0% wood interior decorating environment, 45% wood environment, and 90% wood environment. The Psychological evaluation measured at three time points, was before exposure to the wood environment (T1), 45 minutes after exposure to the wood environment (T2), and 20 hours after exposure to the wood environment (T3). Results : As a result of examining the effect of the wood interior use ratio on psychological variables, After about 20 hours (T3), there were significant differences in mood state_vigor-activity(𝛘²=7.253, p<0.05), mood state_tension-anxiety (𝛘²=7.041, p<0.05), mood state_anger-hostility(𝛘²=8.318, p<0.05), and state anxiety (𝛘²=7.680, p<0.05). State anxiety also showed a significant difference in T2 (𝛘²=8.811, p<.05). As a result of analyzing the effect on satisfaction and subjective impression, there was a significant difference in satisfaction (𝛘²=6.300, p<0.05) and 'pleasant (𝛘²=6.930, p<0.05), airy (𝛘²=6.628, p<0.05), masculine (𝛘²=6.906, p<0.05), ordinary(𝛘²=6.662, p<0.05), natural (𝛘²=13.924, p<0.001), calm (𝛘²=13.106, p<0.001), safe (𝛘²=7.755, p<0.05)'. Conclusion : The wood interior decorating environment had a positive effect on anxiety and mood, such as lowering depressive and anxious mood and increasing positive changes and as the ratio of wood decoration increased, it had a greater positive effect on emotions.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.321-321
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• 2022

Wheat was brought to solve food scarcity with aid from the United States caused by the Korean War. The Korean government launched a campaign to encourage mixed rice and wheat meals due to shortage of rice production in the 1960s, Wheat consumption began in earnest. However, it is difficult to rebuild the domestic wheat production base devastated by the Korean War with the technology at the time. Thus, wheat was mainly consumed from imported in the past. Since then, as wheat consumption has increased due to westernization and diversification of dietary life, wheat became the second staple grain in Korea. In this situation, the government enacted the Wheat Industry Promotion Act to create a basis for sustainable production and consumption of wheat in Korea. This study sought to improve the self-sufficiency of domestic wheat by examining the possibility of using "Ariheuk", a variety of new Korean wheat, as a rice supplement in the same context as the govemment's policy. Wheat has been used as a raw material for the processed food, such as noodles and bread. However, we approached it by using whole wheat as a nutritional grain. Participants were recruited from the agri-food consumer panel conducted by Rural Development Administration. We set a final sample of 525 consumer panels based on the age of census household heads. The experiment was conducted in such a way that participants cooked and ate 100% rice meal and rice containing 20% whole wheat meal. Participants completed the sensory evaluation questionnaire with online. For this experiment, all participants were given same whole wheat product. The sensory evaluation questionnaire consisted of color, glossiness, stickiness, aroma, chewing, sweetness, nuttiness, chewiness, softness, bursting, flavor, texture and swallowability. The sensory evaluation results were analyzed by giving -3 points to +3 points. The former points were given to the response that 100% rice meal is very superior to the response that rice containing 20% whole wheat meal. The latter points were given vice versa. Zero point was given to the response that they are similar each other. As a result, rice with 20% whole wheat meal was better than 100% rice meal in terms of color, aroma, chewiness, bursting and flavor. In case of sweetness and glossiness, there didn't exist significantly different. On the other hands, 100% rice meal was better in terms of softness and swallowability. As a result of ANOVA by age groups, from 30s or younger to 60s or more, there was significant difference among the groups in terms of color, chewiness and bursting. As a result of post-hoc analysis with Duncan's multiple range test (p < 0.05), 50s were evaluated to be significantly superior in color, chewiness and bursting compared to other age groups. In conclusion, it is appropriate to use whole wheat as a supplement to rice in order to improve the self-sufficiency of domestic wheat. As a strategy to promote domestic wheat consumption, in case of Ariheuk, it is necessary to provide an experience through whole wheat tasting and to establish a marketing strategy segmented by age groups.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.1077-1086
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• 2023

The searchable encryption model allows to selectively search for encrypted data stored on a remote server. In a real-world scenarios, the model must be able to support multiple search keywords, multiple data owners/users. In this paper, these models are referred to as Multi Ranked Searchable Encryption model. However, at the time this paper was written, the proposed models use fully-trusted trapdoor centers, some of which assume that the connection between the user and the trapdoor center is secure, which is unlikely that such assumptions will be kept in real life. In order to improve the practicality and security of these searchable encryption models, this paper proposes a new Multi Ranked Searchable Encryption model which uses random keywords to protect search words requested by the data downloader from an honest-but-curious trapdoor center with an external attacker without the assumptions. The attacker cannot distinguish whether two different search requests contain the same search keywords. In addition, experiments demonstrate that the proposed model achieves reasonable performance, even considering the overhead caused by adding this protection process.

• Convergence Security Journal
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• v.23 no.3
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• pp.13-20
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• 2023

This study conducted a digital forensic analysis of Signal and Telegram, two secure messengers widely used in the Android environment. As mobile messengers currently play an important role in daily life, data management and security within these apps have become very important issues. Signal and Telegram, among others, are secure messengers that are highly reliable among users, and they safely protect users' personal information based on encryption technology. However, much research is still needed on how to analyze these encrypted data. In order to solve these problems, in this study, an in-depth analysis was conducted on the message encryption of Signal and Telegram and the database structure and encryption method in Android devices. In the case of Signal, we were able to successfully decrypt encrypted messages that are difficult to access from the outside due to complex algorithms and confirm the contents. In addition, the database structure of the two messenger apps was analyzed in detail and the information was organized into a folder structure and file format that could be used at any time. It is expected that more accurate and detailed digital forensic analysis will be possible in the future by applying more advanced technology and methodology based on the analyzed information. It is expected that this research will help increase understanding of secure messengers such as Signal and Telegram, which will open up possibilities for use in various aspects such as personal information protection and crime prevention.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.627-636
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• 2023

This study was conducted to lay the basis of the need of the self-directed learning ability, critical thinking, communicative ability, problem solving skills for nursing students by confirming the effect of problem based learning classes of nursing students. The data collection period was from March 1 to June 7, 2022. It was provided problem based learning classes to 165 nursing students located at B city. Problem based learning classes were conducted at total of 14 times, and 100 minutes/time. The collected data were analyzed using the frequency and percentage, Cronbach's α, mean and standard deviation with the SPSS Win 21.0 program, and the effectiveness verification of problem based learning classes was analyzed with a paired t-test. As a result of the effectiveness of the problem based learning class, the self-directed learning ability(t=-2.08, p=.039), critical thinking(t=-2.49, p=.014), communicative ability(t=-4.90, p<.001), problem solving skills(t=-4.84, p<.001) of nursing students who took 14 weeks of problem based learning was enhanced. Based on the results of this study, by applying it in various ways to first-year nursing students, it will be possible to use them to improve their competence, major satisfaction, and adapt to college life.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.3
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• pp.166-171
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• 2023

Efficient energy management is a very important factor in sensor networks with limited resources, and cluster techniques have been studied a lot in this respect. However, a problem may occur in which energy use of the cluster header is concentrated, and when the cluster header is not evenly distributed over the entire area but concentrated in a specific area, the transmission distance of the cluster members may be large or very uneven. The transmission distance can be directly related to the problem of energy consumption. Since the energy of a specific node is quickly exhausted, the lifetime of the sensor network is shortened, and the efficiency of the entire sensor network is reduced. Thus, balanced energy consumption of sensor nodes is a very important research task. In this study, factors for balanced energy consumption by cluster headers and sensor nodes are analyzed, and a balancing distribution clustering method in which cluster headers are balanced distributed throughout the sensor network is proposed. The proposed cluster method uses multi-hop routing to reduce energy consumption of sensor nodes due to long-distance transmission. Existing multi-hop cluster studies sets up a multi-hop cluster path through a two-step process of cluster setup and routing path setup, whereas the proposed method establishes a hierarchical cluster routing path in the process of selecting cluster headers to minimize the overhead of control messages.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.231-240
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• 2006

This study conducts a questionnaire survey of 492 middle school students in Jeju islands about the rate of using glasses/contact lens, the place and time of visual acuity test, the period of changing the glasses, the purchase price, the mason to change the glasses, the interrelationship between wearing spectacles and residential district, etc. The results are as follows: 1. 45.33% of the object of investigation use the glasses or contact lens to correct their visual acuity. Among them, the student who wears only glasses is 93.27%, the student who wears glasses and contact lens together is 5.83%, the student who wears only contact lens is 0.90%. 2. As for the period of changing his(her) glasses, below 6 month is 20.18%, from 6 month to one year is 52.02%, from one year to two years is 20.18% and more than two years is 7.62%. 3. As for the purchase price to change his(her) glasses, below 30,000won is 13.45%, from 30,000won to 50,000won is 43.50%, from 50,000won to 70,000won is 23.77%, from 70,000won to 100,000won is 15.25% and more than 100,000won is 4.03%. 4. As for the reason of changing his(her) glasses, cause of change of visual acuity is 55.16%, by broken frame and lens is 27.35%, as want to just change his(her) spectacles is 14.80% and as the others is 2.69%. 5. As for the relative importance in purchasing glasses, the student who thinks more frame is 16.59%, the student who thinks more lens is 67% and the student who thinks both frame and lens is 58.74%. 6. As for the frist time of visual acuity test, 1 grade of elementary school is 37.2%, 3 grade of elementary school is 12.56%, 4 grade of elementary school is 11.66% and 6 grade of elementary school is 11.66%. 7. As for the place of visual acuity test to determine the Dptr. of glasses which wear now, opitican's shop is 57.85% and ophthalmic clinic is 42.15%. 8. As for the frist time of wearing the glasses or contact lens for correct his(her) visual acuity, the most of answer(21.97%) is at 6 grade of elementary school. 9. As for the reason why does not wear the glasses or contact lens though his(her) naked binocular vision is below 0.8, as does not feel any difficulty in daily life is 62.5%, as know that the more wear, the more decrease his(her) visual acuity is 15.65%, by economical circumstance is 6.24% and as not good externally is 15.63%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1619-1637
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• 2000

A review was undertaken to obtain information on the range of beak-trimming methods available or under development. Beak-trimming of commercial layer replacement pullets is a common yet critical management tool that can affect the performance for the life of the flock. The most obvious advantage of beak-trimming is a reduction in cannibalism although the extent of the reduction in cannibalism depends on the strain, season, and type of housing, flock health and other factors. Beak-trimming also improves feed conversion by reducing food wastage. A further advantage of beak-trimming is a reduction in the chronic stress associated with dominance interactions in the flock. Beak-trimming of birds at 7-10 days is favoured by Industry but research over last 10 years has shown that beak-trimming at day-old causes the least stress on birds and efforts are needed to encourage Industry to adopt the practice of beak-trimming birds at day-old. Proper beak-trimming can result in greatly improved layer performance but improper beak-trimming can ruin an other wise good flock of hens. Re-trimming is practiced in most flocks, although there are some flocks that only need one trimming. Given the continuing welfare scrutiny of using a hot blade to cut the beak, attempts have been made to develop more welfare friendly methods of beak-trimming. Despite the developments in design of hot blade beak-trimmers the process has remained largely unchanged. That is, a red-hot blade cuts and cauterises the beak. The variables in the process are blade temperature, cauterisation time, operator ability, severity of trimming, age of trimming, strain of bird and beak length. This method of beak-trimming is still overwhelmingly favoured in Industry and there appears to be no other alternative procedures that are more effective. Sharp secateurs have been used trim the upper beak of both layers and turkeys. Bleeding from the upper mandible ceases shortly after the operation, and despite the regrowth of the beak a reduction of cannibalism has been reported. Very few differences have been noted between behaviour and production of the hot blade and cold blade cut chickens. This method has not been used on a large scale in Industry. There are anecdotal reports of cannibalism outbreaks in birds with regrown beaks. A robotic beak-trimming machine was developed in France, which permitted simultaneous, automated beak-trimming and vaccination of day-old chicks of up to 4,500 chickens per hour. Use of the machine was not successful because if the chicks were not loaded correctly they could drop off the line, receive excessive beak-trimming or very light trimming. Robotic beak-trimming was not effective if there was a variation in the weight or size of chickens. Capsaicin can cause degeneration of sensory nerves in mammals and decreases the rate of beak regrowth by its action on the sensory nerves. Capsaicin is a cheap, non-toxic substance that can be readily applied at the time of less severe beak-trimming. It suffers the disadvantage of causing an extreme burning sensation in operators who come in contact with the substance during its application to the bird. Methods of applying the substance to minimise the risk to operators of coming in contact with capsaicin need to be explored. A method was reported which cuts the beaks with a laser beam in day-old chickens. No details were provided on the type of laser used, or the severity of beak-trimming, but by 16 weeks the beaks of laser trimmed birds resembled the untrimmed beaks, but without the bill tip. Feather pecking and cannibalism during the laying period were highest among the laser trimmed hens. Currently laser machines are available that are transportable and research to investigate the effectiveness of beak-trimming using ablasive and coagulative lasers used in human medicine should be explored. Liquid nitrogen was used to declaw emu toes but was not effective. There was regrowth of the claws and the time and cost involved in the procedure limit the potential of using this process to beak-trim birds.