• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.856-859
• /
• 2010

WSN is composed of a lot of small sensors with the limited hardware resources. In WSN, at the initial stage, sensor nodes are randomly deployed over the region of interest, and self-configure the clustered networks by grouping a bunch of sensor nodes and selecting a cluster header among them. Specially, in Mobile-WSN environment, in which the administrator's intervention is restricted, the self-configuration capability is essential to establish a power-conservative Mobile-WSN which provides broad sensing coverage and communication coverage. In this paper, we propose a self-configuration routing protocol for Mobile-WSN, which consists of step-wise novel protocols for initial deployment, effective joining and removal of sensor nodes, which result in reducing overall power consumption, and extending the lifetime of network.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.4
• /
• pp.77-83
• /
• 2016

Recently, interests for maintenance of transmission tower are increasing to extend life of structures and reduce maintenance cost. However, existing classical diagnosis method of corrosion deteriorated degree on the transmission tower steel members, visual inspection, has a problem that error often due to difference of inspector's individual knowledge and experience. In order to solve the problem, this study carried out to develop the corrosion deterioration inspection tool for transmission tower steel members. This tool is composed of camera equipment and computer-aided diagnosis system. We standardized the photographing method by camera equipment to obtain suitable pictures for image processing. Diagnosis system was designed to evaluate automatically degree of corrosion deterioration for member of transmission tower on the basis of the RGB color image processing techniques. It is anticipated that developed the corrosion deterioration inspection tool will be very helpful in decision of optimal maintenance time for transmission tower corrosion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.505-507
• /
• 2021

In a Wireless Sensor Network (WSN), the wireless data transmission environment plays an important role in system performance. In the proposed mobility model moving distance of sensor nodes has a great influences on communication performance. Transmission/receiving distance (d), path loss (L), sensitivity, Bit Error Rate (BER), Signal-to-Noise Ratio (SNR) are considerations when designing a wireless communication system. MANET is a form of network in which only wireless terminals communicate with each other independently and move without any assistance of an existing infrastructure network. This paper is research on the optimized power usage method which is study on the effect of the moving distance of mobile nodes on the overall energy efficiency of the system in WSN. The purpose of this study is to extend the life of the entire network by proposing the mobile distance of sensor nodes within the communication available range.

• Archives of design research
• /
• v.16 no.4
• /
• pp.173-184
• /
• 2003

As homenetwork has been built at general homes, users want to connect various types of devices and control them. To realize a new environment that most people dream, there have been many services developed, and the various types of devices have been proposed and then their usage and validity have been reviewed. However, as the technical design guideline seems to be prepared soon for the standardization under the situation that has been progressed mainly by technology-lead style so far, making homenetwork a product is expected to be advanced, and therefore now it is the time to discuss the design development at full stage, which is really valuable for users. We have to consider it not to make any alienated class in the society on the whole when considering these devices, and also we have to develop the design by differentiating it toward the direction that we accept users and use environment's special conditions. In addition, each devices should have reliability, no malfunction or error and long life span. At the same time, those products, which can be new changes we can joyfully accept as well as the habits we are already accustomed to, should be developed, and thereby they may naturally have to be absorbed into our present living. The design development direction for future homenetwork can vary depending on our expectation and needs, and it will become a good guidebook for the producer who have to invest much financially or in time. Therefore, this study intends to examine the present network trend and development direction and then suggest the product design direction for future homenetwork.

• Korean Journal of Construction Engineering and Management
• /
• v.14 no.4
• /
• pp.35-45
• /
• 2013

Facility Management is the longest in the building of life cycle. Because it occupies more than 80% of cost, the phase of Facility Management has to be managed and has to be perceived as important as design and construction phase. The method to manage building more efficiently is the introduction of Facility Management System used by CAD and database. But information Requirement is now input by hand in the most Facility Management System. This study aims to analyze the example of applying BIM in the Korea or abroad and the errors of this were deducted by many phase. Lastly, the possible solution is suggested in order to be used in the Facility Management System. This study's benchmarking is COBIE which is developed by the COE(Corps of Engineers) and now popular in the world. The suggestion in this study is the method that I have already mentioned is helpful for a designer to do modeling when a designer uses BIM S/W(software). To be more specific, the method plays a side role in helping data input considering the phase of Facility Management.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.6
• /
• pp.27-35
• /
• 2021

Generally, a proper evaluation method of the aging phenomenon of PV modules is required as the electrical performance and lifespan of PV modules can degrade significantly due to several environmental factors, while they are generally known as devices that are used semi-permanently for more than 20 years. On the other hand, there is a lack of objectivity in the existing evaluation method of the aging phenomenon, which compares the adjusted PV output based on STC with the initial PV module specifications due to the data distortion while adjusting the measured data. Therefore, this study implemented a test device for an aging diagnosis to measure and collect actual data from a PV module section and modeled the data for aging using MATLAB S/W to minimize the variability of the PV output, communication error, and delay. Furthermore, this study confirmed the usefulness of the presented test device for aging diagnosis of the PV modules by diagnosing the total period and yearly-basis degradation rate of aging PV modules as 25.73% and 1.55%, respectively, according to the on-site output characteristics of the PV modules by season.

• Tuberculosis and Respiratory Diseases
• /
• v.40 no.5
• /
• pp.584-594
• /
• 1993

Background: Among the respiratory diseases, there are a lot of cases of pleural effusion. The most common cause is tuberculosis. But the other cause such as lung malignancy is in an increasing tendency because of the development of diagnostic procedure, the decrease of the prevalence of the tuberculosis and the increase of the longevity. We need to know the accurate diagnosis as soon as possible for the correct therapy. Method: A clinical observation was made on 315 cases of pleural effusion seen at Pusan Adventist Hospital, from Jan, 1989 to Dec, 1992. For diagnostic procedure, thoracentesis, lymph node biopsy, bronchoscopy and percutaneous biopsy of the parietal pleura with Cope needle were performed. The following are parameters used in seperating the exudate from the transudate: pleural protein 3.0 g/dl, pleural protein/serum protein ratio 0.5, pleural LDH 200 IU, pleural LDH/serum LDH ratio 0.6, pleural cholesterol 60 mg/dl and pleural cholesterol/serum cholesterol ratio 0.3. Each parameters were compared, and misclassified rate and diagnostic efficiency were calculated. Results: The most common cause of exudate pleurisy was tuberculosis (82.3%) and malignancy was next (12.2%). The chief complaints of pleural effusion were noted as dyspnea (58.7%), chest pain (54.9%), coughing (50.2%) and fever (36.2%). Location of pleural effusion was noted as right side (51.4%), left side (41.3%) and both sides (7.3%). Amount of pleural effusion of the chest X-ray was minimum (46.8%), moderate (40.5%) and maximum (12.7%). Misclassified rates for each parameters in seperating the exudates from the transudates were as follows; protein: 5.2%, pleural protein/serum protein:7.6%, LDH: 13.9%, pleural LDH/serum LDH: 6.9%, cholesterol: 8.0%, pleural cholesterol/serum cholesterol: 5.6%. On the pleural biopsy, the tuberculosis granuloma was 60.8%, malignancy was 13.6%, infection was 2.3% and nonspecific inflammatory reaction was 23.3%. Conclusion: on the basis of the above results, the most common cause of exudative pleurisy was tuberculosis. We think that the plerual cholesterol/serum cholesterol ratio is the most useful supportive parameter in separating the exudates from the transudates. For accurate diagnosis, the pleural biopsy is the first procedure and repeated pleural biopsy of nonspedcific inflammatory reaction is required.

• Korean Chemical Engineering Research
• /
• v.60 no.3
• /
• pp.334-346
• /
• 2022

There is a lack of knowledge and information on the understanding and application of the Process Safety Management (PSM) system, recognized as a major cause of industrial accidents in small-and medium-sized workplaces. Hence, it is necessary to prepare a protocol to secure the practical and continuous levels of implementation for PSM and eliminate human errors through tracking management. However, insufficient research has been conducted on this. Therefore, this study investigated and analyzed the various violations in the administrative measures, based on the regulations announced by the Ministry of Employment and Labor, in approximately 200 small-and medium-sized PSM workplaces with fewer than 300 employees across in korea. This study intended to contribute to the prevention of major industrial accidents by developing a facility maintenance web program that removed human errors in small-and medium-sized workplaces. The major results are summarized as follows. First, It accessed the web via a QR code on a smart device to check the equipment's specification search function, cause of failure, and photos for the convenience of accessing the program, which made it possible to make requests for the it inspection and maintenance in real time. Second, it linked the identification of the targets to be changed, risk assessment, worker training, and pre-operation inspection with the program, which allowed the administrator to track all the procedures from start to finish. Third, it made it possible to predict the life of the equipment and verify its reliability based on the data accumulated through the registration of the pictures for improvements, repairs, time required, cost, etc. after the work was completed. It is suggested that these research results will be helpful in the practical and systematic operation of small-and medium-sized PSM workplaces. In addition, it can be utilized in a useful manner for the development and dissemination of a facility maintenance web program when establishing future smart factories in small-and medium-sized PSM workplaces under the direction of the government.

• Journal of radiological science and technology
• /
• v.32 no.4
• /
• pp.361-370
• /
• 2009

The image quality management of bone mineral density is the responsibility and duty of radiologists who carry out examinations. However, inaccurate conclusions due to lack of understanding and ignorance regarding the methodology of image quality management can be a fatal error to the patient. Therefore, objective of this paper is to understand proper image quality management and enumerate methods for examiners and patients, thereby ensuring the reliability of bone mineral density exams. The accuracy and precision of bone mineral density measurements must be at the highest level so that actual biological changes can be detected with even slight changes in bone mineral density. Accuracy and precision should be continuously preserved for image quality of machines. Those factors will contribute to ensure the reliability in bone mineral density exams. Proper equipment management or control methods are set with correcting equipment each morning and after image quality management, a phantom, recommended from the manufacturer, is used for ten to twenty-five measurements in search of a mean value with a permissible range of ${\pm}1.5%$ set as standard. There needs to be daily measurement inspections on the phantom or at least inspections three times a week in order to confirm the existence or nonexistence of changes in values in actual bone mineral density. in addition, bone mineral density measurements were evaluated and recorded following the rules of Shewhart control chart. This type of management has to be conducted for the installation and movement of equipment. For the management methods of inspectors, evaluation of the measurement precision was conducted by testing the reproducibility of the exact same figures without any real biological changes occurring during reinspection. Bone mineral density inspection was applied as the measurement method for patients either taking two measurements thirty times or three measurements fifteen times. An important point when taking measurements was after a measurement whether it was the second or third examination, it was required to descend from the table and then reascend. With a 95% confidence level, the precision error produced from the measurement bone mineral figures came to 2.77 times the minimum of the biological bone mineral density change. The value produced can be stated as the least significant change (LSC) and in the case the value is greater, it can be stated as a section of genuine biological change. From the initial inspection to equipment moving and shifter, management must be carried out and continued in order to achieve the effects. The enforcement of proper quality control of radiologists performing bone mineral density inspections which brings about the durability extensions of equipment and accurate results of calculations will help the assurance of reliable inspections.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.4
• /
• pp.881-893
• /
• 2007

IT(Information Technology)-based industries have caused a recent digital revolution and the appearance of various types' information service, being largely expanded toward info-communication device company, info-communication service company, software company etc.. Therefore, the needs to evaluate the company value of IT business for M&A or liquidation are growing tremendously. Unlike other industries, however, IT industry has a short lift cycle and so it doesn't have not only a company value-evaluating model for general businesses but the objective one for IT companies yet. So, this thesis analyzes various value-evaluating technique and newly rising ROV. DCF, the change method of company's cash flow including tangible assets into future value, had been applied during the past industrialization economy era and has been persuasively applied to the present. However, the DCF valuation has no option but to make many mistakes because IT companies have more intangible assets than tangible assets. Accordingly, it is ROV, recognized as the new method of evaluating companies' various options normally and quantitatively, that is brought up recently. But the evaluation on the companies' various options is too subjective and theoretical up to now and due to the lack of objective ground and options, it's not possible to be applied to reality. In this thesis, it is found that ROV is more accurate than DCF, comparing DCF and ROV through four examples. As the options applied to ROV are excessively limited, we tried to develop ROV into a new method by deriving five invisible value factors within IT companies. Therefore, on this occasion, we should set up the basic valuation methods on IT companies and should research and develop an effective and various valuation methods suitable to each company like an internet-based company, a S/W developing enterprise, a network-related company among IT companies.