• Membrane Journal
• /
• v.24 no.1
• /
• pp.31-38
• /
• 2014

Rainwater harvesting is a process by which rainwater collected from rooftop or other catchment is purified so that the water can be directly or indirectly used by human beings for beneficial uses. As rainwater is increasingly considered for high quality purposes, membranes have gained an important place in rainwater treatment. It has advantages such as the production of high quality water, small footprint, and affordable energy consumption. Nevertheless, membrane fouling is regarded as a serious problem similar to the cases of water treatment and wastewater reclamation. In this study, we applied microfiltration (MF) membranes for rainwater treatment. In addition, a low pressure ultraviolet (UV) process was also use as a pretreatment to control notonly. To quantify the effect of UV on organic matters, both total organic carbon (TOC) and UV absorbance (UVA) were measured. Moreover, the effect of UV pretreatment on membrane fouling was investigated. Experimental results indicated that the pretreatment of membranes using LPUV was effective to control fouling of MF membranes only when the rainwater was contaminated by algae. This was attributed the reduction and modification of organics after UV treatments. It is likely that the UV/MF process is a promising option for water treatment in decentralized water treatment such as micro water grid systems.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.1
• /
• pp.89-95
• /
• 2009

The current enforce decree of "The Act on the Promotion of Construction Waste Recycling" divides seventeen kinds of construction wastes by property and configuration. Mixed construction waste, one of them classified by the enforce decree, is composed two more than justified construction wastes except refuse soil and rock. In construction wastes justified by enforce decree of this law, most refuse concrete and asphalt concrete of construction wastes are recycled. As well as refuse metal is separated, sorted from bulk them, and merchandised for value. Finally this is used the secondary manufactured products. Even though combustible construction wastes like refuse wood, plastics, fiber can be recycled RDF(Refuse derived fuel) or RPF(Refuse plastic fuel) because of high caloric value and low heavy metal but most of them are discharged as mixed construction waste and then treated by treated by incineration and landfill. Therefore, to control construction waste flow efficiently, construction wastes are classifies first combustible, incombustible, mixed combustible, incombustible and etc. in this study. The combustible waste is consisted refuse wood, plastics, fiber and etc. and incombustible waste contains refuse concrete, asphalt, and etc. Mixed construction is construction waste that can not separate from mixed waste bulk with different kinds.

• Korean Journal of Ecology and Environment
• /
• v.47 no.3
• /
• pp.214-218
• /
• 2014

We introduce a technical equipment of GATe (Green (algae)-tide) water combine developed by K-water. The GATe water combine consists of five modules: main body and buoyant, transfer hopper, screen conveyer, sludge remover, and separator of algae and waste. Also a sprinkler, as the pre-treatment step if necessary, is equipped to the device to spread out environmental-friendly algaecide under the circumstance that the level of algal bloom does not reach to the scum-forming condition. The overall module system of this device is very simple. Based on the field test, the device covers surface area of ca. $500,000m^2day^{-1}$ during the period from May to July, and treats water volume as much as $500,000m^3day^{-1}$ in spite of some variation depending on the water quality condition. The removal efficiency of the device appeared to be over 90%. In addition, the operating duration of the device was able to expand to cover the period between March and November. We expect this new technology can be used to solve algal bloom problems in drinking water resource and public water area.

• Korean Journal of Optics and Photonics
• /
• v.27 no.3
• /
• pp.106-113
• /
• 2016

In this paper, we deal with the wavefront compensation capability of a silicon carbide (SiC) deformable mirror (DM) with 37 actuators for adaptive optics. The wavefront compensation capability of the SiC DM is predicted by computer simulation and examined by actual experiments with a closed-loop adaptive optics system consistsing of a light source, a phase plate, a SiC DM, a high speed Shack-Hartmann sensor, and a control computer. Distortion of wavefront is caused by the phase plate in the closed-loop adaptive optics system. The distorted wavefront has a peak-to-valley (PV) wavefront error of $0.3{\mu}m{\sim}0.9{\mu}m$ and root-mean-square (RMS) error of $0.06{\mu}m{\sim}0.25{\mu}m$. The high-speed Shack-Hartmann sensor measures the wavefront error of the distortion caused by the phase plate, and the SiC DM compensates for the distorted wavefront. The compensated wavefront has residual errors lower than $0.1{\mu}m$ PV and $0.03{\mu}m$ RMS. Consequently, we conclude that we can compensate for the distorted wavefront using the SiC DM in the closed-loop adaptive optics system with an operating frequency speed of 500 Hz.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.3
• /
• pp.47-57
• /
• 2014

LNG plant projects tend to be implemented in overseas owing to its characteristics, so their project management scheme is somewhat different from those of general projects. Value chain in a LNG plant project includes exploration/production of gases, physical liquefaction/chemical conversion processes, transportation and storage. Key factors in the chain include liquefaction process (including ultra-low temperature liquefaction) to convert natural gas into liquid materials or fuel, and Front End Engineering Design (FEED) package, as well as Engineering, Procurement and Construction (EPC) technology comprising control, operation and construction. Success of a complex LNG plant project implemented in overseas depends on decision-making process in project management. Accordingly, to develop a decision-making model in of plant construction, the study extracted none factors in project management by EPC stage and assessed importance of each factor. The result showed that items in both project management and project risk management are important. Especially, the study developed a decision-making model in the construction stage of a LNG plant project based on the project management factors and importance assessment. The developed decision-making model would lay groundwork in building a decision-making system in construction stage of project management.

• Journal of Biomedical Engineering Research
• /
• v.29 no.1
• /
• pp.32-39
• /
• 2008

This paper reports on a realtime OS based master-slave configuration robot control system for laparoscopic surgery robot which enables telesurgery and overcomes shortcomings with conventional laparoscopic surgery. Surgery robot system requires control system that can process large volume information such as medical image data and video signal from endoscope in real-time manner, as well as precisely control the robot with high reliability. To meet the complex requirements, the use of high-level real-time OS (Operating System) in surgery robot controller is a must, which is as common as in many of modem robot controllers that adopt real-time OS as a base system software on which specific functional modules are implemened for more reliable and stable system. The control system consists of joint controllers, host controllers, and user interface units. The robot features a compact slave robot with 5 DOF (Degree-Of-Freedom) expanding the workspace of each tool and increasing the number of tools operating simultaneously. Each master, slave and Gill (Graphical User Interface) host runs a dedicated RTOS (Real-time OS), RTLinux-Pro (FSMLabs Inc., U.S.A.) on which functional modules such as motion control, communication, video signal integration and etc, are implemented, and all the hosts are in a gigabit Ethernet network for inter-host communication. Each master and slave controller set has a dedicated CAN (Controller Area Network) channel for control and monitoring signal communication with the joint controllers. Total 4 pairs of the master/slave manipulators as current are controlled by one host controller. The system showed satisfactory performance in both position control precision and master-slave motion synchronization in both bench test and animal experiment, and is now under further development for better safety and control fidelity for clinically applicable prototype.

• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.739-742
• /
• 2019

In this paper, we propose enhanced DAP(Dose Area Product). The development of enhanced DAP proposed in this paper has optimized the area dose meter that was developed previously. The development of enhanced DAP performed Optimized design of charge integrator and ADC circuit, optimization of line transceiver for RS-485 communication, optimization of display circuit, and optimization of PC-based control program for interlocking and aging. As a result of evaluating the performance of the proposed system in an accredited testing laboratory, Radiation dose dependence and Radiation quality dependence were measured to be 4.2%, which is below ${\pm}15%$ of international standard. Energy range/Tube voltage was confirmed in the range of 30~150kV. The sensitivity difference between sensor field and sensor field area dose sensitivity was measured to be 4.3%, and it was confirmed that it operates normally under ${\pm}15%$ of international standard. In order to measure the reproducibility of the area dosimeter, it was confirmed that it was 0% and it was operated normally at less than 2% of IEC60580 recommendation. Digital resolution was confirmed to be a minimum unit of $0.01{\mu}Gy{\cdot}m^2$ within the error range for the reference dose per hour.

• Journal of IKEEE
• /
• v.23 no.3
• /
• pp.1096-1099
• /
• 2019

In this paper, we propose the protocol for construction of smart factory. The proposed protocol for construction of smart factory consists of an OPC UA Server/Client, a technology of TSN realtime communication, a NTP & PTP time synchronization protocol, a FieldBus protocol and conversion module, a technology of saving data for data transmit latency and synchronization protocol. OPC UA server/client is a system integration protocol which makes interface industrial hardware device and supports standardization which allows in all around area and also in not independent from any platform. A technology of TSN realtime communication provides an high sensitive time management and control technology in a way of sharing specific time between devices in the field of high speed network. NTP & PTP time synchronization protocol supports IEEE1588 standardization. A fieldbus protocol and conversion module provide an extendable connectivity by converting industrial protocol to OPC. A technology of saving data for data transmit latency and synchronization protocol provide a resolution function for a loss and latency of data. Results from testing agencies to assess the performance of proposed protocol for construction of smart factory, response time was 0.1367ms, synchronization time was 0.404ms, quantity of concurrent access was 100ea, quantity of interacting protocol was 5ea, data saving and synchronization was 1,000 nodes. It produced the same result as the world's highest level.

• Journal of Korean Society of Forest Science
• /
• v.100 no.1
• /
• pp.34-41
• /
• 2011

Vegetation structure, composition and diversity were quantified for 10 samples ($10m{\times}10m$) representing woody vegetation and for 30 samples ($1m {\times}3m$) representing understory vegetation in Pinus parviflora and Tsuga sieboldii forest of Taeharyeong, Ulleung-gun (Gyeongsangbuk-do). P. parviflora was limitedly advanced to sapling layer from seedling stage, and based on Mantel tests, composition of canopy layer was not established in ground woody vegetation. Non-metric multidimensional scaling revealed influence of biotic and abiotic factors in species composition of woody and understory vegetation. In the result of multiple regression model, abundance of P. parviflora (density and breast height area) and percent cover of woody debris were significant predict variables for understory diversity. These results suggest that relatively large disturbance is required for regeneration of P. parviflora and T. sieboldii forest, and control of expansion of monocultural understory species that monopolize resources such as Carex blepharicarpa and Maianthemum dilatatum, is necessary for maintenance of diversity.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.1
• /
• pp.167-175
• /
• 2019

To effectively deal with the fire in tunnel which is mostly the vehicle fire, it's more important to suppress the fire at early stage. In urban tunnel, however, accessibility to the scene of fire by the fire fighter is very limited due to severe traffic congestion which causes the difficulty with firefighting activity in timely manner and such a problem would be further worsened in underground road (double-deck tunnel) which has been increasingly extended and deepened. In preparation for the disaster in Korea, the range of life safety facilities for installation is defined based on category of the extension and fire protection referring to risk hazard index which is determined depending on tunnel length and conditions, and particularly to directly deal with the tunnel fire, fire extinguisher, indoor hydrant and sprinkler are designated as the mandatory facilities depending on category. But such fire extinguishing installations are found inappropriate functionally and technically and thus the measure to improve the system needs to be taken. Particularly in a double-deck tunnel which accommodates the traffic in both directions within a single tunnel of which section is divided by intermediate slab, the facility or the system which functions more rapidly and effectively is more than important. This study, thus, is intended to supplement the problems with existing tunnel life safety system (fire extinguishing) and develop the remote-controlled automatic fire extinguishing system which is optimized for a double-deck tunnel. Consequently, the system considering low floor height and extended length as well as indoor hydrant for a wide range of use have been developed together with the performance verification and the process for commercialization before applying to the tunnel is underway now.