• Title/Summary/Keyword: Forward selection

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A Efficient Energy-Saving Forwarding Technique in Wireless Sensor Networks (무선센서네크워크에서 효율적인 에너지 절약 전송 기법)

  • Duc, Thang Le;Nguyen, Dang Tu;Shon, Min-Han;Choo, Hyun-Seung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2011.04a
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    • pp.158-159
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    • 2011
  • Energy efficiency in wireless sensor networks (WSNs) is one significant factor that needs to be considered when making any designs or doing any enhancements on the communication protocol stack. In WSNs using traditional geographic routing, when a sensor node receives a data packet that needs to be transmitted to the sink, it will forward the packet to the neighbor node which is closest to the sink. The traditional geographic routing assumes that the link quality is always 100%. This may cause a bad result as per which we waste too many energy for retransmissions between the two nodes. Thus, the problem here is how to select such node as forwarder at most efficiently in the aspect of both energy consumption and the distance toward the destination. The better node we choose, the more energy we can conserve for the whole network. In this paper, we propose a next-hop forwarding selection metric, called Energy Consumption for Transmission (ECT), which can resolve the above problem in the best way.

Lived Experiences in the Life World of Korean Emerging Adults with Foster Care Backgrounds: A Qualitative Meta-Synthesis (자립준비청년의 생활세계 속 실존 체험에 관한 질적 메타분석)

  • Boram Choi;Jaerim Lee
    • Human Ecology Research
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    • v.62 no.2
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    • pp.279-294
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    • 2024
  • The purpose of this study was to synthesize and interpret the findings of previous qualitative studies that investigated the lived experiences of Korean emerging adults who aged out of the foster care system. Based on our selection criteria, we extracted and analyzed 14 papers that were published between 2010 to 2023. Our meta-synthesis found that the emerging adults' life world consisted of seven domains: family experience, life tasks, education and work, financial issues, home and family, interpersonal relationships, and psychological and emotional issues. We restructured the emerging adults' lived experiences using van Manen's concepts of lived time, lived space, lived things, lived self-other, and lived body. Our meta-synthesis revealed that these emerging adults experienced multidimensional difficulties due to shortcomings of formal and informal social support after aging out of the foster care system. Their difficulties accumulated in their interaction with lived time. Based on the level of their accumulated difficulties, we categorized the emerging adults into stable, struggling, and isolated groups. However, it is important to note that many of them adapted to their own life world and strived to move forward. This qualitative meta-synthesis provides a comprehensive understanding and new interpretation of emerging adults who transition from foster care to independent living in the context of Korea.

Research on Financing the Aquaculture Industry through Participatory Equity Contracting (참여 지분형 계약거래를 통한 양식산업 금융지원 연구)

  • Hwa-Yong Lee;Byung-Suk Han;Hyoung-Koo Kang
    • The Journal of Fisheries Business Administration
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    • v.54 no.4
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    • pp.47-64
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    • 2023
  • The development potential of the aquaculture industry is very high, but there is no financial support for investment except for the government, policy funds, fishery funds, etc. Therefore, we would like to propose a contract transaction in the aquaculture industry. This refers to a forward contract between a producer (fish farmer) and a buyer (mainly a processor or marketer) that stipulates the production and supply of fish products at a predetermined price, but it also refers to an "equity participation type" contract in which both producers and buyers can participate. In other words, it is a model in which part of the fish farm is produced in a way that meets the conditions of the buyer, and part is produced by the producer. This study aims to establish the basic contract trading process. It provides an academic approach to prevent adverse selection and moral hazard due to information asymmetry. It also provides an idea to converge the aquaculture industry with the financial industry using Pecking Order theory. By doing so, we have made it possible for venture capitalists to invest with confidence and provided a process for investors to resolve their concerns, paving the way for the aquaculture industry and the financial industry to develop together.

A scoping review of cephalometric normative data in children

  • Tuan Khang Nguyen;Akanksha Cambala;Manuela Hrit;Elizabeth A. Zimmermann
    • The korean journal of orthodontics
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    • v.54 no.4
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    • pp.210-228
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    • 2024
  • Objective: Understanding the orofacial characteristics and growth patterns in children is essential for both orthodontics and research on children with orofacial abnormalities. However, a concise resource of normative data on the size and relative position of these structures in different populations is not available. Our objective was to aggregate normative data to assess the growth of the orofacial skeletal structures in children with a well-balanced face and normal occlusion. Methods: The MEDLINE, Embase, and Scopus databases were searched. Inclusion criteria included longitudinal and cross-sectional studies on cephalometric measurement of skeletal tissues and a study population ≤ 18 years with a well-balanced face and normal occlusion. Key study parameters were extracted, and knowledge was synthesized. A quality appraisal was performed using a 10-point scale. Results: The final selection comprised of 12 longitudinal and 33 cross-sectional studies, the quality of which ranged from good to excellent. Our results showed that from childhood to adulthood, the length of the cranial base increased significantly while the cranial base angle remained constant; both the maxilla and mandible moved forward and downward. The profile becomes straighter with age. Conclusions: Growth patterns in children with a well-balanced face and normal occlusion follow accepted theories of growth.

Limitations and Challenges of Game Regulatory Law and Policy in Korea (현행 게임규제정책의 한계와 과제 : 합리적인 규제를 위한 고려사항)

  • Kwon, Hun-Yeong
    • Journal of Information Technology Services
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    • v.13 no.3
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    • pp.149-164
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    • 2014
  • The laws and policies governing Korea's game regulations are becoming more and more topics for debate as we enter the Age of Internet. The nature of the basis for Internet regulations and policies are not rooted in freedom of speech or fundamental values of democracy, but rather focused on solving real-world problems such as protection of the youth. Furthermore, the reality is that regulatory devices for keeping the social order such as regulating gambling are being applied directly to games without consideration on the characteristics of Internet gaming, raising concerns that the expansion of constitutional values and innovative empowerment inherent to the Internet are being weakened. The Geun-Hye Park Administration which succeeded Myung-Bak Lee's Administration, even went so far as to implement the so-called "Shutdown Policy", which prohibits access to Internet games during pre-defined time zones and also instigated a time zone selection rule. In order to curb the gambling nature of Internet games, government-led policies such as the mandatory personal identification and prohibition of player selection or in other words mandatory random player selection are being implemented. These institutions can inhibit freedom of speech, which is the basis of democracy, violate the right of equality through unreasonable discrimination between domestic and foreign service providers, and infringe upon the principles of administrative law, such as laws, due process in policies, and balance in among policies and governmental bodies. Going forward, if Korea's Internet game regulations and polices is to develop in a rational manner, regulatory frameworks will need to be designed to protect the nature of the Internet and its innovative values that enable the realization of constitutional values; for example, the Internet acting as the "catalytic media for freedom of expression as a fundamental human right ", which has already been acknowledged by the Korea's Constitutional Court. At the same time, transparent procedures should be put into place that will allow diverse participation of stakeholders including game service providers, game users, the youth and parents in the legislation and enforcement process of regulatory institutions; policies will also need to be transformed to enable not only regulatory laws but also self-regulation system to be established. And in this process, scientific and empirical analysis on the expected effects before introducing regulations and the results of enforcing regulations after being introduced will need to be strengthened.

Effects of visual selection and rotation order on take-off and landing during sequential rotational jumping (연속 회전점프 시 시각선택과 회전순서가 도약과 착지에 미치는 영향)

  • Woo, Byung-Hoon
    • Journal of the Korean Applied Science and Technology
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    • v.39 no.5
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    • pp.701-709
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    • 2022
  • The purpose of this study was to compare the differences according to the visual selection and rotation order during sequential rotational jump for female dancers of a Korean ballet company by classifying them into take-off and landing sections. 10 subjects (age: 26.0±2.9 yrs, height: 163.4±3.3 cm, weight: 46.8±3.6 kg, ballet career: 12.3±5.9 yrs) participated in the study. Using a 3D motion analyzer and a force platform, the height of the body center and the ground reaction force during take-off and landing were measured. According to the visual condition (using both eyes, using left eye, using right eye) and rotation order (first rotation, second rotation), it was analyzed through repeated measurement two-way analysis. Height of the CM was higher in the first jump. In take-off, Fx was lateral force of left foot and medial force of right foot were strong in second rotation, and Fy was forward force was strong in first rotation of right foot. Fz was no significant. In landing, Fy showed backward force was strong when landing the second time from the left foot, and the backward force was strong when using the left sight from the right foot. Fz was strong on the second landing on the left foot and the first landing on the right foot.

A Comparative Study on Prediction Performance of the Bankruptcy Prediction Models for General Contractors in Korea Construction Industry

  • Seung-Kyu Yoo;Jae-Kyu Choi;Ju-Hyung Kim;Jae-Jun Kim
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.432-438
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    • 2011
  • The purpose of the present thesis is to develop bankruptcy prediction models capable of being applied to the Korean construction industry and to deduce an optimal model through comparative evaluation of final developed models. A study population was selected as general contractors in the Korean construction industry. In order to ease the sample securing and reliability of data, it was limited to general contractors receiving external audit from the government. The study samples are divided into a bankrupt company group and a non-bankrupt company group. The bankruptcy, insolvency, declaration of insolvency, workout and corporate reorganization were used as selection criteria of a bankrupt company. A company that is not included in the selection criteria of the bankrupt company group was selected as a non-bankrupt company. Accordingly, the study sample is composed of a total of 112 samples and is composed of 48 bankrupt companies and 64 non-bankrupt companies. A financial ratio was used as early predictors for development of an estimation model. A total of 90 financial ratios were used and were divided into growth, profitability, productivity and added value. The MDA (Multivariate Discriminant Analysis) model and BLRA (Binary Logistic Regression Analysis) model were used for development of bankruptcy prediction models. The MDA model is an analysis method often used in the past bankruptcy prediction literature, and the BLRA is an analysis method capable of avoiding equal variance assumption. The stepwise (MDA) and forward stepwise method (BLRA) were used for selection of predictor variables in case of model construction. Twenty two variables were finally used in MDA and BLRA models according to timing of bankruptcy. The ROC-Curve Analysis and Classification Analysis were used for analysis of prediction performance of estimation models. The correct classification rate of an individual bankruptcy prediction model is as follows: 1) one year ago before the event of bankruptcy (MDA: 83.04%, BLRA: 93.75%); 2) two years ago before the event of bankruptcy (MDA: 77.68%, BLRA: 78.57%); 3) 3 years ago before the event of bankruptcy (MDA: 84.82%, BLRA: 91.96%). The AUC (Area Under Curve) of an individual bankruptcy prediction model is as follows. : 1) one year ago before the event of bankruptcy (MDA: 0.933, BLRA: 0.978); 2) two years ago before the event of bankruptcy (MDA: 0.852, BLRA: 0.875); 3) 3 years ago before the event of bankruptcy (MDA: 0.938, BLRA: 0.975). As a result of the present research, accuracy of the BLRA model is higher than the MDA model and its prediction performance is improved.

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Presurgical Nasoalverolar Molding in Fraternal Twins with Bilateral Cleft Lip and/or Palate: A Case Report (양측성 구순/구개열을 가진 이란성 쌍둥이를 대상으로 한 술전 비치조정형술: 증례보고)

  • Kim, Jinsun;Kim, Youngjin;Nam, Soonhyeun;Kim, Hyunjung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.41 no.1
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    • pp.72-79
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    • 2014
  • Cleft lip and palate(CLP) is one of the most common craniofacial deformities that requires systemic management involving a multidisciplinary team approach. Although there has been great improvement in the field of cleft surgery, surgical approach alone cannot resolve the various problems in treating cleft lip and palate. Hence the need for presurgical treatment was appreciated and especially, the concept of presurgical nasoalveolar molding was applied to treat unilateral and bilateral cleft lip and palate patients. Presurgical nasoalveolar molding(PNAM) of unilateral cleft mainly aims to recover nasal symmetry while the objectives of pre-surgical nasoalveolar molding in the bilateral cleft are to elongate the columella, to erect the tip of nose, and to reposition the forward displaced premaxillary region. This report covers the case of fraternal twins diagnosed with bilateral cleft. Retraction of the premaxillary region and nasoalveolar molding were conducted for 70 days until cheiloplasty, using elastic bands and nasoalveolar molding appliances. After cheiloplasty, there had been improvements in the length of columella and the position of forward-displaced premaxilla for both patients compared to their initial states. The esthetics was also satisfactory for both the surgery and the parents. In order to maximize the efficacy of the appliance, three components should be in balance; patients' adaptation to the appliance, parents' cooperation and proper selection and careful adjustment of the appliance by the dentist.

A Study on the Nutritional Status of Lunch Box of Elementary School Students in Kyungnam Area (경남지역 국민학교 아동의 도시락 영양실태에 대한 조사연구)

  • 이성숙
    • Journal of the Korean Home Economics Association
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    • v.25 no.3
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    • pp.49-61
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    • 1987
  • The main purpose of these studies was the improvemen of nutritional supply and of the future physical coditions. The two groups which were regional difference were chosen and research for the nutritional status of elementary school students. The nutritional status of lunch-box between one elementary School of 98 students in the 6th year grade(hence-forward it was called "A-Group"), located at the center of Masan City, being provided the milk and the other elementary School of 134 students in the 6th year grade(hence-forward it was called "B-Group"), located in the small farm and fishing villages of Kusan-myun, Euichang-kun, Kyungnam province, were seweyed from the period of Nov. 20, 1986 to Dec. 4, 1986 and conclusion were as follows: 1. Nutritional status of lunch-box 1) It is indicated that in the case of A-Group, the nutirtional intake except animal protein and vitamin A were lower than the Recommended Daily Allowances of Korenas and in the case B-Group, was also lower than except vitamin A respectively and especially in both groups, the percentage of Fe was lowest and intended difference between A Group and B was that B-Group in the intake of calorie, fat, Ca, Fe and etc were lower than A-Group. 2) The total calorie-intake was short of the extent to approx. 83.8% as compared to the RDA. On the viewpoint at ratio of intake of caloric nutrients, A-Group appeared to be 69.5 : 16.5 : 14 and B-Group, 77.5 : 19.5 : 13 in order carbohydrate, protein and fat. As a result of the above ratio, B-Group depended upon carbohydrate as a staple food more than A-Group. It can be considered that the total calorie-intake is short, and that the amount of lunch-box was greatly insufficient for taking optimal nutrition. 3) Calorie, carbohydrate, vitamin B, and niacin were taken nutrition from a staple food and protein from at similar ratio of staple and subsidiary food and fat, Fe, vitamin A, vitamin B1, adn vitamin C were mainly taken from a staple food. It was indicated that B-Group was higher at the supply-ratio by a staple food than A-Group. 3. The realities of improvement of physical conditions The improvement of physical conditions of the two groups were lower in accordance with Korea Children's Growth Standard, but B-Group was inferior to A-Group. 4. Seeing that the total intake of nutrition being taken at lunch time was lower as campared to the RDA intakes between the two Groups were remakably different, a lot of efforts should be made to improve the calorie-intake for the purpose of the farm and fishing villages. For balanced intake of nutrition, selection of foods and various cooking ways are important, therefore, throughout the expansion of the lowest stratum of elementary schools for milk-supply, high-quality protein, fat, Ca, vitamin B2 and etc should be supplied to the growing students. That can narrow the gaps of the intake of nutrition and physical condition between the students who live in cities and the students who live in the country.

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The Effect of Wireless Channel Models on the Performance of Sensor Networks (채널 모델링 방법에 따른 센서 네트워크 성능 변화)

  • 안종석;한상섭;김지훈
    • Journal of KIISE:Information Networking
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    • v.31 no.4
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    • pp.375-383
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    • 2004
  • As wireless mobile networks have been widely adopted due to their convenience for deployment, the research for improving their performance has been actively conducted. Since their throughput is restrained by the packet corruption rate not by congestion as in wired networks, however, network simulations for performance evaluation need to select the appropriate wireless channel model representing the behavior of propagation errors for the evaluated channel. The selection of the right model should depend on various factors such as the adopted frequency band, the level of signal power, the existence of obstacles against signal propagation, the sensitivity of protocols to bit errors, and etc. This paper analyzes 10-day bit traces collected from real sensor channels exhibiting the high bit error rate to determine a suitable sensor channel model. For selection, it also evaluates the performance of two error recovery algorithms such as a link layer FEC algorithm and three TCPs (Tahoe, Reno, and Vegas) over several channel models. The comparison analysis shows that CM(Chaotic Map) model predicts 3-time less BER variance and 10-time larger PER(Packet Error Rate) than traces while these differences between the other models and traces are larger than 10-time. The simulation experiments, furthermore, prove that CM model evaluates the performance of these algorithms over sensor channels with the precision at least 10-time more accurate than any other models.