• Journal of information and communication convergence engineering
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• 제15권2호
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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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• 제11권4호
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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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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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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.

• 한국콘텐츠학회논문지
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• 제18권3호
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• pp.101-113
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• 2018

실시간으로 데이터를 획득하고 평가하는 것이 중요한 군용 점검 장비와 같은 시스템에서는 운영체제 레벨에서 실시간 처리가 가능해야 한다. 기술의 발전으로 기존 장비를 휴대용 단말로 대체하려는 요구가 있으나, 안드로이드가 적용된 휴대용 단말은 실시간성이 요구되는 시스템에 적합하지 않다. 안드로이드에서는 가비지 컬렉션을 통해 가용 메모리를 확보하는데, 이 작업이 수행되는 동안 다른 태스크가 중단되어 특정 태스크의 주기성을 보장할 수 없다. 본 논문에서는 이를 해결하기 위해 안드로이드의 가비지 컬렉션 실행을 제어하는 구조를 설계 및 구현하였다. 실시간 작업이 필요한 시간 동안 가비지 컬렉션을 제어하여 실시간 성능을 보장하며, 안드로이드에 실시간 성능 보장을 위한 RTiK을 적용하였다. 성능 평가를 위해 5ms 주기 태스크의 호출 주기를 측정하였으며, 제어 이전에는 태스크의 34.31%만 주기가 보장되었으나, 제어를 통해 98.18%의 태스크 주기가 만족되어 안드로이드에 실시간성을 제공하였다.

• Animal Bioscience
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• 제34권10호
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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.

• 패션비즈니스
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• 제23권3호
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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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• 제13권4호
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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.

• 자원ㆍ환경경제연구
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• 제9권5호
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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.

• 성인간호학회지
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• 제29권1호
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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.

• 한국정보통신학회논문지
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• 제21권4호
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• pp.731-736
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• 2017

본 논문에서는 능동형 RFID 시스템의 표준인 ISO/IEC 18000-7의 성능을 개선하기 위하여 간소화된 태그 수집 알고리즘을 제안한다. 제안한 알고리즘에서는 태그 수집 라운드의 시작을 나타내는 수집 명령을 수정하여, 이전 라운드의 LP 구간 응답에 대한 결과를 포함시킨다. 수집 명령을 수신한 태그는 자신이 응답한 슬롯의 충돌 여부를 확인하고, 별도의 점대점 읽기 명령과 슬립 명령 없이 자신의 데이터 슬롯으로 추가적인 데이터를 전송하고 슬립 상태로 천이한다. 표준에서의 수집 라운드는 일련의 수집 명령, 수집 응답, 읽기 명령, 읽기 응답, 및 슬립 명령으로 구성된다. 반면, 제안한 태그 수집 알고리즘은 표준과는 달리 하나의 수집 라운드가 수집 명령 및 수집 응답으로만 구성된다. 성능 분석결과, 태그의 수가 300개일 때 제안한 기법의 평균 식별지연은 표준에 비하여 16% 개선됨을 알 수 있었다.