• Journal of the Korea Organic Resources Recycling Association
• /
• v.9 no.4
• /
• pp.89-98
• /
• 2001

Present vermicomposting technology needs the broad land. Because of the high land cost, the land saving technology such as multistage must be needed. And present operation practices are mostly based on human power, mechanization and automation is needed. Also, present control practices based on individual experience need the scientific base control system. Even though the rough estimation of organic waste treatment showed that vermicompostiong could obtain more benefits than costs. But, the estimation is based on an ideal case without considering the technical and market. Generally, vermicomposting is considered as the more expensive technology than composting. Therefore, the practical proof the economic factor would be the most important to the market increase. Vermicomposting as the recycling technology has better condition than incineration and landfill. Propagation and advocating focused on its environmentally sound aspects would be needed continuously. Especially, demonstration and distribution of household vermicomposting would be a good approach. Vermicomposting facilities area was becoming larger, and earthworm feeding materials were also expanding to various organic sludges. These trends showed that vermicomposting is being enlightened to treat and recycle the organic wastes.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.3
• /
• pp.267-272
• /
• 2012

Carbon emission generated by energy issues is one of the major problems which all countries concern. The International Energy Agency recommends to improve 15-30[%] of energy efficiency than now. Government has pushed the domestic energy saving policies and incentives and penalties were also given in that direction. Pumps are widely used to transfer fluids and they consume at least 20[%] power of each nation. Their loss of energy is huge if they have been operated at low efficiency for long time. Low efficiency of these pumps is often due to incorrect design or degradation. Pump efficiency can be measured to estimate energy loss. If it is low, the pump may be repaired or replaced with new one. This paper introduces thermodynamic method to measure pump efficiency using only two kinds of sensors for temperature and pressure. It can calculate best efficiency point(BEP) of actual systems easily and fast. Its values were compared with the real performance curve provided by pump maker and we got almost similar performance curves from the repeated experiment.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.3
• /
• pp.13-17
• /
• 2011

There was a transition from participatory irrigation management (PIM) to public irrigation management (PubIM) in Korea when Korea Rural corporation and Community (KRC) merged with Farm Land Improvement Associations (FLIAs), which had managed 60 % of irrigation areas. While making a number of achievements, some problems occurred in the public irrigation management, such as lack of farmers' participation, increased amount of water usage, and elevating operating costs. Accordingly, this paper suggested ways to increase efficiency in water usage and reduce operating costs under the public management through the motive power of farmers participation. First, WUGs replaced the discarded water management committee should be reorganized to revive the concept of PIM in the form of autonomously reinforced one and the roles and functions of WUGs and the board of representatives should be strengthened. The member of new type of WUGs should participate in the national and regional water management committees as a stakeholder of irrigation water user. And also new type of WUGs initiates not only the management of irrigation water but also the management of irrigation water quality and non-point source pollution in the watersheds. Those additional activities of WUGs should be properly compensated. Second, subsidies (direct payments) should be provided to faithful farmers as an incentive for their labor supply. Third, water fees could be charged to large scale agriculture companies. Fourth, professional managers could be hired, management targets would be adjusted, and incentives should be offered. These efforts are expected to improve the irrigation management by encouraging farmers' participation under public system.

• Journal of Biosystems Engineering
• /
• v.31 no.4 s.117
• /
• pp.342-348
• /
• 2006

Aerial application using an unmanned agricultural helicopter became necessary for both labor saving and timely spraying. In the previous paper, a rotor system was developed and lift capability was evaluated. The experimental results were compared with simulated predictions using the CFD-ACE program. From the simulation, the relative velocity on the top surface of the blade airfoil increased, resulting in the pressure drop. The CFD analyses were revealed that a drag resistance on the leading edge of the airfoil, a wake at the trailing edge, and a positive pressure underneath the bottom surface were observed. As the results of the simulation, total lifts of 56.8, 74.4 and $95.0kg_f$ were obtained at the 6, 8 and $10^{\circ}$ of AAT (angle of attack), respectively. The simulation results agreed reasonably up to $10^{\circ}$ of AAT. However, at a greater AAT $(<12^{\circ})$ the simulated total lift continuously increased to $105kg_f$, comparing with a decreasing experimental total lift due to the lack of engine power. At a stiff angle of $18^{\circ}$ AAT, a wake was observed at the trailing edge of the airfoil. A rated operating condition determined from the previous paper was also verified through the simulation.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.9 no.2
• /
• pp.52-57
• /
• 2001

ln this study, the questionnaire survey was performed to obtain the basic data on current situations and challengeable aspects of vermicomposting industries. The questionnaire contained the four main categories such as vermicomposting facilities, feeling marerials, earthworm breeding and cast handling. The results was summarized as followings: 1. Vermicomposting facilities area was becoming larger, and earthworm feed was also expending to various organic sludges. These trends showed that Vermicomposting is being enlightened to treat and recycle the organic wastes in Korea. 2. Present Vermicomposting technology needs the broad land. Because of the high cost of land in Korea, the land saving technology such as multistage must be needed. And present operation practices are mostly based on human power, mechanization and automation is needed. Also, present control practices are based on individual experience need the scientific base control system. 3. Considering situations of organic wastes management in Korea, the technical development and the practical improvement of Vermicomposting as the waste recycling will be needed.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.3
• /
• pp.6-12
• /
• 2011

Electric vehicles and robots are real-time distributed control systems composed of multiple drive subsystems using micro controller units. Each control subsystem should be modular, compact, power saving, interoperable and fault tolerable in order to be incorporated into the networked real-time distributed control system. Under the networked real-time distributed control the synchronization problem can be occurred to the position and orientation tracking control due to the load variance, mismatch and time delay between the multiple drive subsystems. This paper suggests two types of position synchronization control of the single link manipulators. One of them is composed of cross controller, Kalman filter and disturbance observer, and the other uses the generation of target trajectories to minimize the gradient vector of the scalar function which is composed of the sum of square errors between the reference input vector and the output vectors. The availability of the proposed control schemes is shown through the control experiments.

• Korea Journal of Hospital Management
• /
• v.7 no.3
• /
• pp.102-120
• /
• 2002

The purpose of study is to understand human-technology integration mechanism by using the study model that takes the core concept and motivation assumptions of technology acceptance model(TAM) into account. This study identifies three motivation mechanisms in adopting or using computer mediated communication(CMC) tool for work. The mechanism comprises with extrinsic, extrinsic motivation, and subjective norm pressure. One hospital with 430 beds and 367 human power was identified and we administered the questionnaire during their work hours. There is 32.4% response rate. The fitting index of the study model surpass the acceptable level, GFI = .980 for none-users, GFI =.986 for users, NNFI = .973 for none-users, and NNFI = .989 for users. In the case of none-users, perceived ease of use determines perceived usefulness that explains behavioral intention to use. As a result, adotpers' usage motivation is based on extrinsic motivation that does not consider their affective factor, attitude, in use of CMC. Users considers their attitudes as the mediating factor of all behavioral beliefs for using CMC continually. Thus, users are likely to depend their adoption behaviors on their affective factor. Moreover, users' behavioral intention is subject to pressures of use from other persons who are important to them, such as supervisor, director, or boss. Achieving human-technology integration in a hospital may cause cost saving and work efficiency. However, the success of information system should base on a profound understanding of employees' adoption behaviors in rejecting, adopting, using, continually using of IT, and organization culture in using IT.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.9
• /
• pp.1025-1031
• /
• 2019

This study proposes a PCS that enables efficient operation of seawater pumps for ships by implementing ML-based algorithms. Seawater temperature, RPM and power consumption data are acquired from two ships with PCS, analyzed with regression analysis method, and new algorithms are presented. Using the algorithms presented, Ship A saved about 36% compared to the PCS application, and ML-based algorithms in certain sea temperatures of 19 to 27 degrees Celsius and above 32 degrees Celsius were about 1% lower than Ship A's PCS. Ship B saved about 50% compared to PCS not applied, and about 2% more than Ship B's PCS in waters above $19^{\circ}C$, a specified sea temperature. The derived data can be used to suggest the optimum pump speed and sea route. In addition, the trend of acquired data can be used to infer the performance of the pump or the timing of elimination of the MGPS when efficiency becomes poor.

• Journal of Korea Society of Industrial Information Systems
• /
• v.14 no.5
• /
• pp.113-123
• /
• 2009

As environmental issues are emerging, many efforts are globally conducted to reduce waste of energies and resources for green growth, as well as low-carbon emitting and replacement of document papers with digital files and images. On the other hand, it may require much time and efforts for users to find the proper image files on the web, where enormous un-standardized digital files are flourishing. Therefore, power and resource consumption may also grow up again in searching and retrieving files. This paper suggests efficient system design and implementation for fast and precise massive image contents retrieval for saving the energies and resources. Eventually it will contribute to green growth in computing environment.

• Journal of IKEEE
• /
• v.23 no.4
• /
• pp.1461-1464
• /
• 2019

In this paper, we propose the development of embedded board for integrated radiation exposure protection fireman's life-saving alarm capable of location tracking and radiation measurement. The proposed techniques consist of signal processing unit, communication unit, power unit, main control unit. Signal processing units apply shielding design, noise reduction technology and electromagnetic wave subtraction technology. The communication unit is designed to communicate using the wifi method. In the main control unit, power consumption is reduced to a minimum, and a high performance system is formed through small, high density and low heat generation. The proposed techniques are equipment operated by exposure to poor conditions, such as disaster and fire sites, so they are designed and manufactured for external appearance considering waterproof and thermal endurance. The proposed techniques were tested by an authorized testing agency to determine the effectiveness of embedded board. The waterproof grade has achieved the IP67 rating, which can maintain stable performance even when flooded with water at the disaster site due to the nature of the fireman's equipment. The operating temperature was measured in the range of -10℃ to 50℃ to cope with a wide range of environmental changes at the disaster site. The battery life was measured to be available 144 hours after a single charge to cope with emergency disasters such as a collapse accident. The maximum communication distance, including the PCB, was measured to operate at 54.2 meters, a range wider than the existing 50 meters, at a straight line with the command-and-control vehicle in the event of a disaster. Therefore, the effectiveness of embedded board for embedded board for integrated radiation exposure protection fireman's life-saving alarm has been demonstrated.