• Journal of Wetlands Research
• /
• v.4 no.1
• /
• pp.51-61
• /
• 2002

The wetland is a biologically integrated system consisting of water, soil, bacteria, plants, and animals. The wetland helps sustain the ecosystem, control the micro-climate and flood, maintain the ground water level, and provide fishing grounds. From the environmental standpoint, the wetland plays a vital role in reducing water pollution by filtering out sand and other polluted matters, producing oxygen, absorbing chemicals and nutrients. For these reasons, interest in restoring the wetlands has been steadily increasing. Artificial wetland, which is also referred to as created wetland or constructed wetland, is an alternative to natural wetland. Like natural wetland, artificial wetland is environmentally friendly and can effectively lower pollutant levels. The Korea government is actively reviewing the construction of artificial wetlands in mining and water supply areas to decrease nonpoint pollutant sources. This paper attempts to develop a pollutant removal model for the water quality improvement function of artificial wetlands. Artificial wetland can improve the quality of the water; however, depending on the type of water inflow, vegetation and hydrology, its effect can be different.

• Journal of Biomedical Engineering Research
• /
• v.32 no.3
• /
• pp.251-256
• /
• 2011

Virtual colonoscopy is favored over conventional colonoscopy because its non-invasive procedure can avoid complications that may happen in a conventional approach and because it can cleanse colon electronically instead of uncomfortable conventional colon cleansing. Electronic Colon Cleansing(ECC) has to deal with not only removing tagged fecal material but also recovering Partial Volume Effect(PVE) due to tagging material. This paper proposes an ECC method restoring inherent natural PVE while previous approaches focused only on reducing PVE due to tagged fecal material. The proposed method reduces PVE using 3-dimensional adaptive density correction and then replaces tagged fecal material into air. Next, it generates natural PVE for the replaced air adjacent to soft tissue and finally makes smooth transition of gray values for soft tissue adjacent to the replaced air. The proposed method applied to eleven patient data, and showed promising results.

• Environmental Engineering Research
• /
• v.21 no.1
• /
• pp.52-57
• /
• 2016

Sediment is a useful natural source but deteriorated continually by anthropogenic and industrial sources. Therefore, it is imperative to search a suitable method for improving or restoring sediment quality. Sediment has been tested to identify the effects of some external agents on a polluted area for 28 days. Chemical analysis and total viable counts (TVC) test have been conducted for 4 days interval to assess their performance. The analyses of chemical oxygen demand (COD), acid volatile sulfide (AVS), total phosphorous (T-P), total nitrogen (T-N) indicate that the chemical agents was more efficient to improve sediment quality whereas the microbial agent was more efficient for nutrient releasing from sediment. Oxygen releasing property of the chemical agent was thought to be providing with more congenial environment for the higher growth of the bacterial community than the direct application of microbial agents.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.23 no.1
• /
• pp.3-12
• /
• 1986

This paper investigates the static configurations and the dynamic behaviors of a single point mooring line. To obtain the static configuration and static tension distribution along the mooring line, including the effect of fluid nonlinear drag and the elasticity of the line, the Runge-Kutta fourth order numerical method was used. The relationship between the horizontal excursion and the horizontal restoring force component of the mooring line, which is very important to a mooring line design, and the effect of a subsurface buoy on the static configuration are presented. In nonlinear dynamic analysis including nonlinear fluid drag acting on the line and geometrical nonlinearity for large deflections, finite element method using updated Lagrangian was used to obtain the solution. In the case of upper end harmonic excitation of the mooring line, the dynamic motion and the tension were also presented.

• Journal of the Society of Naval Architects of Korea
• /
• v.30 no.4
• /
• pp.39-45
• /
• 1993

In order to analyze the rolling motion of a ship in random beam waves we have used the equivalent linearization method. The quadratic nonlinear damping, the cubic and quintic nonlinear restoring moments were added to a single degree of freedom linear equation of roll motion. The irregular excitation moment was assumed to be the Gaussian white noise. The statistical characteristic of the response by the equivalent linearization method was compared with the simulation result.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.28 no.6
• /
• pp.480-483
• /
• 2002

Treatments for restoring the function and esthetics of missing teeth include fixed bridge, partial denture, orthodontic movement, implantation and autotransplantation. However, there is no absolute indications for each techniques. Due to undevelopment of root and root resorption after autotransplantation, the success rate of autotransplantation over the past decades have been low. Recently. with the study on biological principles of the healing of periodontal ligament, the success rate of autotransplantation began to improve. We report the cases of successful autotransplantation which resulted in ideal healing of periodontal ligament, gingiva and alveolar bone.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2004.11a
• /
• pp.212-219
• /
• 2004

The effect of frequency and amplitude of the OWC (Oscillating Water Column) motion on the nonlinear reaction forces in an air duct arc studied experimentally. Experimental OWC model is idealized as a simple circular cylinder with an orifice type air duct located at the middle of the top rid. Reaction forces due to forced heave oscillation are measured and analyzed. By subtracting the effect of inertia forces and restoring forces, pneumatic damping force and added spring force are deduced. The effects of the frequency and amplitude of the heave motion are discussed. Also, the effects of solidity of the duct on the reaction forces are discussed.

• Journal of Families and Better Life
• /
• v.31 no.4
• /
• pp.65-82
• /
• 2013

This study focuses on the roles of family and parents as primary environments for character education of children and adolescents, examines surrounding micro and macro environments in a bioecological model, and explores parent support methods for restoring character education in family. For this study, we had interviews with 54 parents(44 mothers & 10 fathers). Through the interviews we found difficulties of character education in family and analyzed them in children and teenagers, parents, school, and social-cultural dimensions based on the bioecological model. On the basis of the parents' perception for these difficulties, we proposed how to support the roles of family and parents for recovering character education in family. The policy methods were propsed in family, school, and society dimensions. This study is meaningful in that it suggests evidence base for making the parent support policy.

• Journal of Navigation and Port Research
• /
• v.33 no.9
• /
• pp.629-634
• /
• 2009

Vessels stability problems need to resolve the nonlinear mathematical models of rolling motion. For nonlinear systems subjected to random excitations, there are very few special cases can obtain the exact solutions. In this paper, the specific differential equations of rolling motion for intact ship considering the restoring and damping moment have researched firstly. Then the partial stochastic linearization method is applied to study the response statistics of nonlinear ship rolling motion in beam seas. The ship rolling nonlinear stochastic differential equation is then solved approximately by keeping the equivalent damping coefficient as a parameter and nonlinear response of the ship is determined in the frequency domain by a linear analysis method finally.

• Proceedings of the KIEE Conference
• /
• 1998.11b
• /
• pp.569-571
• /
• 1998

In this paper, we propose a method of restoring blurred images by an edge-sensitive adaptive filter. The direction of the edge is estimated using the properties of 2-D block FFT. Reduction of blurring due to the added noise during image transfer and the focus of lens caused by shooting a fast moving object is very important. To remove this phenomenon effectively, we can use the edge information obtained by processing the blurred images. The proposed algorithm estimates both the existence and the direction of the edge. On the basis of the acquired edge direction information, we choose the appropriate edge-sensitive adaptive filter, which enables us to get better images than images obtained by methods not considering the direction of the edge. The performance of the proposed algorithm is shown in the simulation result.