• Journal of KIISE:Databases
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• v.36 no.3
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• pp.189-197
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• 2009

Top-k queries are important to many wireless sensor applications. Conventional Top-k query processing algorithms install a filter at each sensor node and suppress unnecessary sensor updates. However, they have some drawbacks that the sensor nodes consume energy extremely to probe sensor reading or update filters. Especially, it becomes worse, when the variation ratio of top-k result is higher. In this paper, we propose a novel Top-k query processing algorithm for energy-efficiency. First, each sensor determines its priority as the order of data gathering. Next, sensor nodes that have higher priority transmit their sensor readings to the base station until gathering k sensor readings. In order to show the superiority of our query processing algorithm, we simulate the performance with the existing query processing algorithms. As a result, our experimental results show that the network lifetime of our method is prolonged largely over the existing method.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.137-144
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• 2016

This paper proposes characteristics of management system for defense system development. This research shows how effectiveness of SBA (simulation-based acquisition) can be represented even necessity of SBA is recognized by researchers. To achieve this goal there are two key information, (1)the cost for modeling and simulation and (2) number of trial and error of a certain step in a phase. This paper presents user interface of gathering those two key information and a way of showing the effectiveness of SBA using those two information. In this work, all the data gathering for calculation of effectiveness should be considered as a saving logs. The contribution of this research is in presenting quantitative value representing effectiveness of SBA and proposing a system architecture for deriving the quantitative effectiveness.

• Journal of the Korea Society of Computer and Information
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• v.23 no.1
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• pp.75-84
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• 2018

In this study, the researchers attempted to automate the process of painting the characters on the road surface, which is currently done by manual labor, by using the information and communication technology. Here are the descriptions of how we put in our efforts to achieve such a goal. First, we familiarized ourselves with the current regulations about painting letters or characters on the road, with reference to Road Mark Installation Management Manual of the National Police Agency. Regarding the graphemes, we adopted a new one using connection components, in Gothic print characters which was within the range of acceptance according to the aforementioned manual. We also made it possible for the automated program to recognize the graphemes by means of the feature dots of the isolated dots, end dots, 2-line gathering dots, and gathering dots of 3 lines or more. Regarding the database, we built graphemes database for plotting information, classified the characters by means of the arrangement information of the graphemes and the layers that the graphemes form within the characters, and last but not least, made the character shape information database for character plotting by using such data. We measured the layers and the arrangement information of the graphemes consisting the characters by using the information of: 1) the information of the position of the center of gravity, and 2) the information of the graphemes that was acquired through vertical exploration from the center of gravity in each grapheme. We identified and compared the group to which each character of the database belonged, and recognized the characters through the use of the information gathered using this method. We analyzed the input characters using the aforementioned analysis method and database, and then converted into plotting information. It was shown that the plotting was performed after the correction.

• Korea journal of population studies
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• v.35 no.2
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• pp.185-208
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• 2012

This study examines how married immigrant women's social networks affect their life satisfaction in Korea. A multiple-regression analysis is conducted using data from Nationwide Multicultural Family Survey in 2009. The major findings are as follows. First, the frequency of keeping in touch with their family in the mother country significantly affects the level of satisfaction, while the family size in Korea is not making a significant difference. Second, the strength of "Korean Network" - strong bridging network - is highlighted. Third, family gathering variables affect the level of satisfaction. An interesting point is found from the nationality segmentation. The case of women from Japan, with the longest duration in Korea, shows that both of the family and the non-family gathering variables significantly affect the life satisfaction. It is interpreted that family network dominates in the earlier stage of marriage, but the other social networks also play the role as the duration extends.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.22-33
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• 2018

Recently domestic manufacturing companies have been experiencing worsening profitability and stunted growth due to the long-term economic recession and the rapid rise of developing countries such as China and Southeast Asia. These difficulties force many companies to concentrate their core competencies on new value creation and innovation in order to gain momentum for new growth. Enterprise Resource Planning (ERP) has been considered as one of viable solutions. Among the various modules in ERP, shop floor control function in the production management module is rather limited. In order to overcome this problem, Manufacturing Execution System (MES) has been used as a subsystem which has a strong information gathering power and flexibility. Both systems interact closely with each other. In particular, ERP requires fast, accurate shop floor information at MES. This paper describes how to synchronize relevant information between ERP and MES with theory of constraints (TOC). The processing time information transmitted from the MES workplace is received at the ERP workplace. In the process, the received processing time is causing information distortion in ERP, when the information gathering standard of MES is different from the ERP information interpretation standard. The Drum-Buffer-Rope theory of TOC was applied to resolve this problem, therefore, information synchronization between both systems was made. As a precondition, the standard time of the upper ERP system was rearranged according to the capacity constraints resource. As a result, standard time restructuring has affected changes in labor costs. Standard labor costs have come close to actual ones, and information synchronization of MES transmission data has improved the reliability of standard product costs, such that it enabled various company-wide restructuring actions to be much more effective.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.4
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• pp.1317-1341
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• 2021

Nowadays, the Internet of Things (IoT) is adopted to enable effective and smooth communication among different networks. In some specific application, the Wireless Sensor Networks (WSN) are used in IoT to gather peculiar data without the interaction of human. The WSNs are self-organizing in nature, so it mostly prefer multi-hop data forwarding. Thus to achieve better communication, a cross-layer routing strategy is preferred. In the cross-layer routing strategy, the routing processed through three layers such as transport, data link, and physical layer. Even though effective communication achieved via a cross-layer routing strategy, energy is another constraint in WSN assisted IoT. Cluster-based communication is one of the most used strategies for effectively preserving energy in WSN routing. This paper proposes a Bio-inspired cross-layer routing (BiHCLR) protocol to achieve effective and energy preserving routing in WSN assisted IoT. Initially, the deployed sensor nodes are arranged in the form of a grid as per the grid-based routing strategy. Then to enable energy preservation in BiHCLR, the fuzzy logic approach is executed to select the Cluster Head (CH) for every cell of the grid. Then a hybrid bio-inspired algorithm is used to select the routing path. The hybrid algorithm combines moth search and Salp Swarm optimization techniques. The performance of the proposed BiHCLR is evaluated based on the Quality of Service (QoS) analysis in terms of Packet loss, error bit rate, transmission delay, lifetime of network, buffer occupancy and throughput. Then these performances are validated based on comparison with conventional routing strategies like Fuzzy-rule-based Energy Efficient Clustering and Immune-Inspired Routing (FEEC-IIR), Neuro-Fuzzy- Emperor Penguin Optimization (NF-EPO), Fuzzy Reinforcement Learning-based Data Gathering (FRLDG) and Hierarchical Energy Efficient Data gathering (HEED). Ultimately the performance of the proposed BiHCLR outperforms all other conventional techniques.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.135-138
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• 2020

무선 센서 네트워크에서 모바일 싱크의 도입은 기존의 고정된 위치의 싱크를 사용하는 WSN에서 발생하는, 싱크 주변 노드들과 외곽 노드들 간의 에너지 불균형 문제(에너지 핫스팟 문제)를 어느 정도 해결할 수 있게 하였다. 그러나 모바일 싱크의 에너지 제약으로 인해 싱크가 모든 노드를 방문하여 데이터를 수집할 수 없기 때문에, 앵커(또는 헤드)라고 불리는 특정 노드에서 데이터를 모으고, 모바일 싱크는 이러한 앵커 노드들만을 방문하는 방법이 널리 사용되고 있다. 최근 연구에서는 모바일 싱크가 보다 효율적으로 에너지 불균형 문제를 해결하기 위하여 모바일 싱크 이동 경로 및 앵커 노드 선정 최적화 방법이 활발히 연구되고 있다. 본 연구에서는 태양 에너지 기반 센서 네트워크를 위한 영역 기반 앵커 선정 기법 및 모바일 싱크 이동 경로 선택 기법을 제안한다. 제안 기법은 각 노드가 수집하는 태양 에너지의 활용을 최대화하고, 에너지 핫스팟 문제를 완화하기 위해 두 개의 라인(영역)을 설정하고 이 라인을 따라 앵커 노드가 선정된다. 모바일 싱크는 데이터 수집을 위해 이 두 라인을 왕복 이동 경로로 택하여 라인 내의 앵커 노드를 방문한다. 실험을 통해 제안 기법이 기존 기법보다 에너지 불균형 문제가 완화되어 노드의 정전 시간이 줄어들고, 이에 따라 모바일 싱크에서 수집되는 데이터의 양이 증가하는 것을 확인하였다.

• Journal of Drive and Control
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• v.21 no.2
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• pp.23-29
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• 2024

Potatoes are one of the world's four major crops, and domestic consumption is currently increasing in Korea. However, the mechanization rate of potatoes is very low, and especially, harvesting is the most labor-intensive task in potato production. In Korea, potato-collecting work depends on manpower, so it is necessary to develop a gathering-type harvester that can be used for processes from digging to harvesting. Therefore, in this study, a self-propelled-type potato harvester was developed, and its performance was analyzed to mechanize harvesting. The potato harvester was developed to have a crawler-type driving part with a 60 hp diesel engine and consisted of a digging part that digs potatoes from the ground, a vertical transporting part that transfers the dug potatoes to the height of the collection bag, a separating part that separates debris, such as stones and soil, and a collecting part that loads the collection box. A field test of the potato harvester was conducted, and performance was evaluated by the damage, loss, and debris mixing proportions, which were 2.5%, 2.8%, and 2.6%, respectively. The working capacity was 1.2 h/10 a. The economic analysis results showed that the cost of harvesting work could be reduced by 12.7% compared to manual harvesting.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.6
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• pp.46-58
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• 1999

The purpose of this research was to find out the state of the nursing performance of the home care nurses in Seoul in order to provide the data for the practical work guide. The data were collected from fifty home care nurses working in 22 institutions located in Seoul. The research tool used for this research was modified and tested by Song Jong-Rye(1999) which was originally modified the standard tool of American Nurses Association (1998) and was partly supplement and adjusted for this research. The reliability of this tool was Cronbach's $\alpha$=.0982. The collected data were statistically processed using SAS for t-test, ANOVA. $Scheff\'{e}$ test. Among the surveyees, 50% have been working as a home care nurse more than three years and 74.0% of them were married. And 52% have B.S degree with certification of home care nurse from the certification program for Home Care Nurses affiliated at nursing schools. Half of the home care nursing organizations were based on the general hospitals, and most(78%) of the responsible senior personnels of those organizations were nurses. The following results are drawn from this research. 1) The level of nursing performance by the task sectors General performance level of home care nurses was relatively high in grade of 3.06 from total 4.00. Among the task sectors. the ethical field scored the highest points, and the next were nursing intervention, professional training, and data gathering, and the research sector scored the lowest point. 2) The level of nursing performance by general features of home care nurses Statistically relevant correlation between performance according to the duration of working experience as a nurse(p=0.8951) and performance according to the duration of working as home care nurse(p=0.2263) did not emerge. Also, performance by marriage status(p=0.2218), education(p=0.5733), and taking the certification program for home card nurse(p =0.1560) has no statistically meaningful correlation. 3) The level of nursing performance by the type of home care nursing organizations There exists a significant difference(p=0.002) between performances by the types of organizations. Most of the responsible senior personnels of the home care nursing organization were nurses. The level of nursing performance of the home care nursing organization under nurse management was relatively higher than that of home care nursing organizations led by medical doctors or non-medical professional, but this was not proved as statistically meaningful(p =0.3617). 4) The level of nursing performance by task sectors according to the characteristic of home care nursing service organization There exists a significant difference between nursing performances by task sectors according to the characteristics of home care nursing organization(p=0.002). In case of model research center of one College of Nursing, the nursing performance in the sectors of organization, theory, and data gathering were lower than that of in hospital based home care nursing service. And in case of local home care centers, performances in sectors of organization, theory, data gathering, nursing intervention. professional training, and research sectors were significantly low. Based on the obtained results, overall performance of home care nurses can be appraised as relatively good. Especially, performances in sectors of the nursing intervention, nursing plan. and data gathering including the in direct nursing were recorded high scores. From this, it can be concluded that high quality of nursing is relatively practicing for home patients at these days. Since the high quality of nursing for patients was directly related to the level of nursing performances of home care nurses, it is required to improve practical performance level of them by making constant evaluation and running continual education program and supplementing curriculum for the sectors with low scores.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1379-1381
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• 2002

Recently, environmental pollution by livestock excretion is gathering strength as livestock industry is advanced on a large scale. Bio-gas is generated more than about 70 precent if remove impurities in the course of extracting bio-gas to use livestock excretion. In this paper, we developed a device that can use it in heating after extracting bio-gas from livestock excretion collected in livestock farmhouse and can supply electricity by using generator developed in itself. Also, because this system is epoch-making no discharge system to solve smear of existing method, it is expected that we have effects to prevent environmental pollution and get alternation energy and burden on the institution to treat livestock excretion of a pig breeder is solved, if use it.