• Journal of information and communication convergence engineering
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• v.15 no.2
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• pp.79-84
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• 2017

In a cognitive radio network (CRN), cognitive radio users (CUs) should be powered by a small battery for their operations. The operations of the CU often include spectrum sensing and data transmission. The spectrum sensing process may help the CU avoid a collision with the primary user (PU) and may save the energy that is wasted in transmitting data when the PU is present. However, in a time-slotted manner, the sensing process consumes energy and reduces the time for transmitting data, which degrades the achieved throughput of the CRN. Subsequently, the sensing process does not always offer an advantage in regards to throughput to the CRN. In this paper, we propose a scheme to find an optimal policy (i.e., perform spectrum sensing before transmitting data or transmit data without the sensing process) for maximizing the achieved throughput of the CRN. In the proposed scheme, the data collection period is considered as the main factor effecting on the optimal policy. Simulation results show the advantages of the optimal policy.

• International Journal of Advanced Culture Technology
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• v.11 no.4
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• pp.202-209
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• 2023

In the 21st century, the dualistic worldview of the Cold War era collapsed and we entered an era of new creation and fusion. The fusion of different designs between East and West, the design activities of traditional clothing from the past, the use of new materials that are continuously being developed, and the mixing of unique items are being conducted in various fields. However, research is being conducted by combining fusion characteristics with hair. In addition, the period is short and the amount of research is small. Therefore, this study analyzed hairstyles of fusion images shown in hair collection using data of Juno Hair collection from 2013 to 2022 as analysis data and examined types of fusion images shown in the work of folk images, mixed images, and future images. Oriented images were divided into three categories and analyzed. In this study, we added Results of such research can be used not only as data for predicting future fashion trends, but also as basic data for exploring new design developments. In future research, it is expected that convergent research will be conducted, such as analyzing fusion images from an integrated perspective.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.13-18
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• 2009

Building is a major energy consumer, and now many efforts are made to save energy in the design and using equipments. The most noticeable achievement in those efforts is a building energy performance assessment program. But most programs are not satisfying enough to provide exact meteorological data, and data source and calculation, and data collection period are not clearly defined. That is common in most of domestic programs. This study collects typical meteorological data in 16 items and analyzes them with Visual DOE 4.0 to compare with existing data. The comparison found that revised data shows a 11% increase on average during cooling period from June to September, and a 13% decrease on average during heating period from December to February, in terms of building heating and cooling load in a monthly basis.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.101-113
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• 2018

Systems such as military inspection equipment which it is important to acquire and evaluate data in real-time should be able to real-time processing at the operating system level. As technology advances, there is a demand for replacing existing equipment with mobile device, but mobile devices with Android are not suitable for systems requiring real-time performance. On Android, garbage collection ensures free memory, while other tasks are interrupted while this task is performed, which cannot guarantee periodicity of particular tasks. In this paper, we designed and implemented a structure to control execution garbage collection of Android to solve this problem. Real-time performance is ensured by controlling garbage collection during the time required for real-time operation, and RTiK(Real-Time implanted Kernel) is applied to ensure real-time performance on Android. In order to evaluate the performance, we measured the call period of the 5ms period task, and, only 34.31% of the task was guaranteed before the control, but the task period of 98.18% was satisfied through control, providing real-time performance to Android.

• Animal Bioscience
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• v.34 no.10
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• pp.1632-1642
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• 2021

Objective: The hypothesis was that apparent ileal digestibility (AID), basal endogenous losses, and standardized ileal digestibility (SID) of amino acids (AA) are not affected by adding acid to collection containers or bags used to collect ileal digesta from pigs. Methods: Twenty-four growing barrows (initial body weight: 77.8±4.5 kg) that were fitted with a T-cannula in the distal ileum were fed diets for three 7-d periods. An N-free diet and 3 diets containing corn, soybean meal, or wheat middlings as the sole source of AA were used. Within each period, each of the 4 diets were fed to 6 pigs. Among the 6 pigs, digesta from 3 pigs were collected in bags containing no HCl, whereas 40 mL of 3 N HCl was included in the bags used to collect digesta from the remaining 3 pigs. Every other bag collected from each pig was emptied into a container without adding HCl, whereas the remaining bags were added to a container along with 40 mL of 3 N HCl for each bag. All digesta were stored at -20℃ immediately after collection. Data were analyzed using a model that included feed ingredient, HCl in bags, HCl in containers, and all 2-way and 3-way interactions as fixed effects. No 3-way interactions were significant, and data were, therefore, reanalyzed independently for each diet as a 2×2 factorial. Results: There were no interactions between adding HCl to collection bags and to containers, and no effects of adding HCl to collection bags or containers for AID, basal endogenous losses, or SID of most AA were observed. Conclusion: It is not necessary to add acid to digesta collection bags or collection containers if ileal digesta are stored at -20℃ immediately after collection.

• Journal of Fashion Business
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• v.23 no.3
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• pp.85-100
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• 2019

This study examines changes in consumer perceptions of fashion shows, which are critical elements in the apparel industry and a means to represent a brand's image and originality. For this purpose, big data in clothing marketing, text mining, semantic network analysis techniques were applied. This study aims to verify the effectiveness and significance of fashion shows in an effort to give directions for their future utilization. The study was conducted in two major stages. First, data collection with the key word, "fashion shows," was conducted across websites, including Naver and Daum between 2015 and 2018. The data collection period was divided into the first- and second-half periods. Next, Textom 3.0 was utilized for data refinement, text mining, and word clouding. The Ucinet 6.0 and NetDraw, were used for semantic network analysis, degree centrality, CONCOR analysis and also visualization. The level of interest in "models" was found to be the highest among the perception factors related to fashion shows in both periods. In the first-half period, the consumer interests focused on detailed visual stimulants such as model and clothing while in the second-half period, perceptions changed as the value of designers and brands were increasingly recognized over time. The findings of this study can be utilized as a tool to evaluate fashion shows, the apparel industry sectors, and the marketing methods. Additionally, it can also be used as a theoretical framework for big data analysis and as a basis of strategies and research in industrial developments.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.72-78
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• 2021

Currently, the Korean wave is not limited to popular culture, but has a significant impact not only on Korea's national image but also on the improvement of Korean companies' products and image of Korea. In this study, using Textom to confirm the change in foreign tourists' image of Korea, the data collection period was 1 year of 2020, when COVID 19 occurred, as a collection period for "Korea and foreigner" and related key words, each Hallyu content, and ranked in the top 80 keywords were derived. Centrality analysis for semantic network visualization was performed using UCINET6, and through CONCOR analysis, 7 groups 'K-Quarantine ', 'K-Drama', 'K-Movie', 'K-Beauty', 'K-Shopping', It was clustered into 'K-Tech' and 'K-Pop'. As a result of the analysis, the image of Korea abroad generally recognized the Korean Wave as cultural content, but after the outbreak of COVID 19, it is judged that it has been recognized as a country with a successful case of K-Quarantine.

• Environmental and Resource Economics Review
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• v.9 no.5
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• pp.903-924
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• 2000

This paper examines the alternative method to measure the state of overall economic activity. The macroeconomic variables, used for business cycle, take more than a month after a period for collection and aggregation. The electricity generation data is compiled in mechanical ways just after the period. Based on this fact, we develop the two stage estimation method for coincident economic indicators in order to detect the business cycle in an earlier period, using Stock-Watson's Dynamic Factor Model. Using monthly data from 1970 to 1999, it is found that the experimental coincidence economic indicators are well-fitted to data and also that the estimates of two stage estimation method have good explanatory power, equivalent to the experimental coincidence economic indicators. While the RMSE of coincidence economic indicators is found to be 1.27%, that of the experimental coincidence economic indicators is found to be 1.31% and that of the two stage estimation method is around 1.44%. If we take consideration into the fact that it measures the business cycle in one month earlier, we come to the conclusion that the two stage estimation is of great use.

• Korean Journal of Adult Nursing
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• v.29 no.1
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• pp.63-75
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• 2017

Purpose: This study was to explore and describe the reported experiences of elderly spouses who care their bedridden spouse in the home. Methods: The participants of this study were 14 male and female elderly spouses who live in B metropolitan city and have provided care for more than six months. Data were collected from July 3 to November 6, 2014. Data analysis was done simultaneously with data collection, using the analytical methods of Strauss and Corbin for Grounded theory. Results: The core category was identified as 'going together bearing a heavy burden of care in old age.' In this study, the caring process of elderly spouses can be explained in terms of three stages such as 'a period of trial and error,' 'a period of mastering a role,' and 'a period of role transcendence'. Conclusion: The results of this study can provide an intervention framework to reduce the heavy burden of caring for an elderly spouse.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.731-736
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• 2017

In this paper, we propose a simplified tag collection algorithm to improve the performances of ISO/IEC 18000-7, which is a standard for an active RFID system. The proposed algorithm modifies the collection command that enables to start a tag collection round. The modified collection command includes the results of the listen period response for the previous collection round. Tags that receive the collection command check the collision status for their responses. If there is no collision, tags transmit their additional data and go into the sleep mode without the point-to-point read command and sleep command. A collection round for the standard consists of a collection command and response, a read command and response, and sleep command. On the other hand, in the proposed algorithm, a collection round consists of a collection command and response. The simulation results showed that the proposed algorithm can improve the identification delay about 16% compared with the standard when the number of tags are 300.