• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.2
• /
• pp.153-159
• /
• 2016

Gwangyang traffic safety designated area is composed of 3 fairways (Deep water fairway, inbound fairway, and outbound fairway). However, inbound vessels can't use this passage because of Samyeo rock and artificial fishing banks in inbound route. The problem with the rocks and artificial fishing banks has been raised by ship navigators and authorities of the port. This research is about the safety evaluation and management plan of the passage, and we conducted maritime traffic simulation using a model based on a ship operator risks. As a result, assuming that future marine traffic volume is the same as the present, and if the ship operators use 3 fairways and not two, it showed risk reduction of 46.4 % (vessels over 50,000 DWT using DW route) and 57.1 % (vessels over 10,000 DWT using DW route). Also, in a traffic volume condition which is the same as the present, to induce vessels over 50,000 DWT to use DW route is effective in mitigating of risks. Meanwhile, in a condition which increased the traffic volume by 150 %, it is more effective to induce vessels to use DW route. This research is the result of analysis using the model based on ship operator risks, and not cost-effectiveness analysis on the removal of Samyeo rock and artifical fishing banks. This research is expected to be used on setting up the sea route and management plan (particularly, restriction on passing DW route).

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.1
• /
• pp.28-37
• /
• 2010

In this paper, the IC (Integrated Circuit) for multi-channel asynchronous communication was designed by using FPGA and VHDL language. The existing chips for asynchronous communication that has been used commercially are composed of one to two channels. Therefore, when communication system with two channels or more is made, the cost becomes high and it becomes complicated for communication system to be realized and also has very little buffer, load that is placed into Microprocessor increases heavily in case of high speed communication or transmission of high-capacity data. The designed IC was improved the function and performance of communication system and reduced costs by designing 8 asynchronous communication channels with only one IC, and it has the size of transmitter/receiver buffer with 256 bytes respectively and consequently high speed communication became possible. To detect errors between communications, it was designed with digital filter and check-sum logic and channel MUX logic so that the malfunction can be prevented and errors can be detected more easily and input/output port regarding each communication channel can be used flexibly and consequently the reliability of system was improved. It was composed and simulated logic of VHDL described by using Cyclone II Series EP2C35F672C8 and QuartusII V8.1 of ALTERA company. In order to show the performance of designed IC, the test was conducted successfully in QuartusII simulation and experiment and the excellency was compared with TL16C550A of TI (Texas Instrument) company and ATmegal28 general-purpose micro controller of ATMEL company that are used widely as chips for asynchronous communication.

• Journal of the Korea Concrete Institute
• /
• v.22 no.1
• /
• pp.19-27
• /
• 2010

Aging and severe environments are major causes of damage in reinforced concrete (RC) structures such as buildings and bridges. Deterioration such as concrete cracks, corrosion of steel, and deformation of structural members can significantly degrade the structural performance and safety. Therefore, effective and easy-to-use methods are desired for repairing and strengthening such concrete structures. Various methods for strengthening and rehabilitation of RC structures have been developed in the past several decades. Recently, FRP composite materials have emerged as a cost-effective alternative to the conventional materials for repairing, strengthening, and retrofitting deteriorating/deficient concrete structures, by externally bonding FRP laminates to concrete structural members. The main purpose of this study is to investigate the effectiveness of adaptive neuro-fuzzy inference system (ANFIS) in predicting behavior of circular type concrete column retrofitted with FRP. To construct training and testing dataset, experiment results for the specimens which have different retrofit profile are used. Retrofit ratio, strength of existing concrete, thickness, number of layer, stiffness, ultimate strength of fiber and size of specimens are selected as input parameters to predict strength, strain, and stiffness of post-yielding modulus. These proposed ANFIS models show reliable increased accuracy in predicting constitutive properties of concrete retrofitted by FRP, compared to the constitutive models suggested by other researchers.

• Journal of Korean Academy of Nursing
• /
• v.25 no.3
• /
• pp.472-484
• /
• 1995

The purpose of this study was to develop a home health care model in the public health system and to test the effectiveness of the model. Seven com-munity health practitioners in Yon- Cheon county. Kyunggi province, carried out home health care service for this research. The subjects of the home health care were a total of 111 community residents with chronic health problems and risk-prone infants and children; 29 persons with hypertension, 18 persons with diabetes, 12 persons with neurologic problems, 12 elderly, and 40 infants and children. During the period of study, from December, 1993 to March, 1995, a demonstrative home health care model was developed in the Yon-Cheon County community health centers with the cooperation of the Yon-Cheon Medical Center and Yon-Cheon Public Health Center for the first six months. A home care practice manual and recording system for home visits were also co-developed by the researchers and community health practitioners. Four workshops and monthly conferences were held for this purpose. Actual home care practice took place for two months, and on-going evaluation and replanning accompanied this process. The result of the evaluation of home care service were as follows. 1) For persons with hypertension, diabetes, neurologic problems, there was significant improvement in knowledge of disease and care, but no significant difference was seen in health behavior or symptoms after home care service. 2) No significant difference was seen in level of self esteem or depression after reminiscence therapy among 12 elderly subjects. 3) There were significant differences in satis-faction toward child rearing and parental sup-port, but no significant difference In education needs for parental role after home care service among parents of infants and children. 4) There was significant improvement in the quality of life among the subjects after the home care service. 5) Subjects responded that they were highly satisfied with the home care service given by the community health practitioners. Although, the actual implementation period was very short, and not all of the evaluation outcomes showed significant improvement, the home health care model of community health practitioners was, in general, positively evaluated. Through this re-search, the possibility of community health practitioners working as active home care personnel in the public health care system is supported. Further research with an expanded area and subjects for a longer period is recommended. Cost effectiveness research is also needed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.2B
• /
• pp.100-107
• /
• 2007

Recently, a study of BcN(Broadband convergence Network) is progressing continuously, and it is important to improve the quality of the service according to subscribers because a scale of network is about to be larger. It is more important to manage QoS(Quality of Service) of all subscribers in layer 2 than layer 3 network since managing it in layer 3 network cost both additional processes and large hardware. Moreover, QoS based on Best-Effort service has been developed because tots of subscribers should use limited resource in BcN. However, they want to be supplied with different service even though they pay more charge. Therefore, it is essential to assign the different bandwidth to subscribers depending on their level of charge. The method of current Rate Limiter limits the bandwidth of each port that does not offer fair service to subscribers. The Rate Limiter proposed in this paper limits bandwidth according to each subscriber. Therefore, subscribers can get fair service regardless of switch structure. This new Rate Limiter controls the bandwidth of subscribers according to the information of learning subscriber and manages maximum performance of Ethernet switch and QoS.

• Journal of the Korean institute of surface engineering
• /
• v.49 no.2
• /
• pp.166-171
• /
• 2016

Cathodic protection is widely recognized as the most cost effective and technically appropriate corrosion prevention methodology for the port, offshore structures, ships. When applying the cathodic protection method to metal facilities in seawater, on the surface of the metal facilities a compound of calcium carbonate($CaCO_3$) or magnesium hydroxide($Mg(OH)_2$) films are formed by $Ca^{2+}$ and $Mg^{2+}$ ions among the many ionic components dissolving in the seawater. And calcareous deposit films such as $CaCO_3$ and $Mg(OH)_2$ etc. are formed by the surface of the steel product. These calcareous deposit film functions as a barrier against the corrosive environment, leading to a decrease in current demand. On the other hand, the general calcareous deposit film is a compound like ceramics. Therefore, there may be some problems such as weaker adhesive power and the longer time of film formation uniting with the base metal. In this study, we tried to determine and control the optimal condition through applying the principle of cathodic current process to form calcareous deposit film of uniform and compact on steel plate. The quantity of precipitates was analyzed, and both the morphology, component and crystal structure were analyzed as well through SEM, EDS and XRD. And based on the previous analysis, it was elucidated mechanism of calcareous deposit film formed in the sacrificial anode type (Al, Zn) and current density (1, 3, $5A/m^2$) conditions. In addition, the taping test was performed to evaluate the adhesion.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.506-512
• /
• 2018

The fine dust generated in the home and restaurant business occupies a low ratio of about 4% of the total fine dust emissions. However, at the foodservice business, the rate of change of the pollutant concentration is very high, so that the temporary fine dust concentration can be measured up to 60 times. The pollutants generated from non-industrial combustion plants consist of particulate fine dust and gaseous organic compounds. To remove these pollutants, cleaning dust collection system, which is an effective system for simultaneous removal of gaseous and particulate matter, is applied. This is a method of increasing the probability of diffusion capture of the Brownian motion by pressurized liquid injection method using the atomizing nozzle. The dust removal efficiency of the fine dust collecting system was analyzed by nozzle spraying air pressure condition and angle using the manufactured fine dust removing system. As a result, it was confirmed that the efficiency of removal of fine dust and gaseous organic compounds was more than 90%. The developed system is expected to be highly usable in the future because it can remove particulate dust from the existing plant hood system without any installation cost.

• Journal of Korea Technology Innovation Society
• /
• v.22 no.3
• /
• pp.362-381
• /
• 2019

The purpose of this study is to examine how two factors among various affecting factors of technological innovation, i.e. sectoral system of innovation and R&D support service, were actually applied in the case of NUC Electronics. This company has achieved high level of innovation performance through change of injection port and improvement of extracting rate. This was possible because each component of sectoral system of innovation system was matched with the innovation activity. The improvement of the performance in NUC Electronics was attributable to its own innovation efforts and R&D support service of government research institute. In the process of technological innovation, the company could receive high-level services in areas such as product design and virtual experiments that companies can not solve themselves. It can be said that the role of government and public institutions to support the shortage of SMEs was important. In terms of each component of sectoral system of innovation, we found that there were many opportunities of new technology; sustainability was low; imitation was easy; appropriability was low but it has dualily; accumulation of technology was relatively high, availability of external knowledge was high. At the same time, both of the company and the network played an important role, and market conditions were very favorable. In terms of R&D support services, it is a direct effect that a great deal of time and cost savings have been achieved through virtual experiments on the material and shape of the screw. As an indirect effect, the core competence of the company has been greatly strengthened by utilizing the momentum of technology development through external support, hence the company could establish the structure of virtuous circle of innovation.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.5
• /
• pp.569-575
• /
• 2022

It is most desirable to build a crane training program in the same evvironment as the actual port, but it has problem such as time constraint and cost. To overcome these limitations, next-generation training programs based on AR/VR are receiving a lot of attention. In this paper, a prototype of a harbor crane training system based on virtual reality was designed and implemented. The system implemented in this paper consists of two elements: an Arduino-based IoT terminal and an HMD equipped with a Unity application program. The IoT terminal consists of 2 controllers, 2 toggle switches, and 8 button switches to process data generated according to the user's operation. The HMD uses Oculus Quest2 and is connected to the IoT terminal through wireless communication to provide user convenience. The training system implemented in this paper is expected to provide trainees with a training environment independent of time and place through virtual reality and to save time and money.

• Geophysics and Geophysical Exploration
• /
• v.25 no.3
• /
• pp.129-139
• /
• 2022

Analog-based streamers for ultra-high-resolution seismic surveys are capable of additional noise ingress in water, but the specifications cannot be expanded through interconnections. Foreign-produced digital streamers have been introduced and used primarily at domestic research institutes; however, the cost is high and smooth maintenance is challenging. This study investigates the localization of ultra-high-resolution digital streamers capable of high-resolution imaging of a geological structure. A digital streamer capable of 24-bit, 10 kHz digital sampling of up to 64 channel data was developed through research and development. Various quantitative specifications of the system were designed and developed close to the benchmark model, Geometrics' GeoEel streamer, and the number of modules that make up the system was drastically reduced, reducing development costs and making it easier to use. The field applicability of the developed streamer system was evaluated in an in situ experiment conducted in the waters around the Port of Yeong-il Bay in Pohang in April 2022.