• Journal of Advanced Research in Ocean Engineering
• /
• v.2 no.1
• /
• pp.22-27
• /
• 2016

This experimental study deals with the mechanism of spoilers that cause scouring around pipelines. The design methodology was applied to spoilers for accelerating pipelines that undergo self-burial into the sand-bed and evaluated using approaching experimental analysis. The experimental study was conducted to investigate the self-burial ability of submarine pipelines with two types of sand-bed models: silt and sand. Spoilers of different heights were attached to the top of the pipeline for each experiment case. The relationship between the relative scour depth and spoiler height was evaluated by applying different flow velocities and sand diameters and comparative analysis was performed with values obtained from similarity experiments and theory. The experimental study will be useful in establishing a database for the design of spoilers.

• Journal of Ocean Engineering and Technology
• /
• v.30 no.4
• /
• pp.310-319
• /
• 2016

If a spoiler was attached to the pipeline investigated in a previous study, a strong flow and vortex at the lower part caused scouring and thus an asymmetric pressure distribution, which assisted in the analysis of the self-burial structure where a down force was applied to the pipe. However, only the fluid-pipe interaction was considered, excluding the medium (seabed), when practically burying the pipeline. Thus, this study applied a numerical model (LES-WASS-2D) to directly analyze the non-linear interactions among the fluid, pipe, and seabed in order to perform numerical simulations of a pipeline with a spoiler installed on the seabed. This allowed the self-burial mechanism of a pipeline with a spoiler to be analyzed in the same context as the previous study that considered only the fluid-pipe interaction. However, when a pipeline was installed on the seabed, a strong flow and vortex were found at the front of the bottom, and a spoiler accelerated the fluid resistances. This hydraulic phenomenon will reinforce the scouring and down force on the pipeline. In the general consideration of the numerical analysis results by the specifications and arrangements of the spoiler, a pipeline with a spoiler was found to be the most effective for the self-burial function.

• Ocean Systems Engineering
• /
• v.2 no.4
• /
• pp.257-269
• /
• 2012

This paper provides a practical stochastic method by which the maximum equilibrium scour depth around spherical bodies exposed to long-crested (2D) and short-crested (3D) nonlinear random waves can be derived. The approach is based on assuming the waves to be a stationary narrow-band random process, adopting the Forristall (2000) wave crest height distribution representing both 2D and 3D nonlinear random waves, and using the regular wave formulas for scour and self-burial depths by Truelsen et al. (2005). An example calculation is provided.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.28 no.3
• /
• pp.146-159
• /
• 2016

This study used Navier-Stokes Solver(LES-WASS-2D) for analyzing hydrodynamic characteristics with high order in order to analyze self-burial mechanism of pipeline with spoiler under steady flow. For the validity and effectiveness of numerical model used, it was compared and analyzed with the experiment to show flow characteristics around the pipeline with and without the spoiler. And the hydraulic(flow, vortex, and pressure) and force characteristics were numerically analyzed around the pipeline according to the incident velocity, and shape and arrangement of spoiler. Primarily, if the spoiler is attached to the pipeline, the projected area is increased resulting in higher flow velocity toward the back and strong vortex caused by wake stream in the back. Secondly, the spoiler causes vertically asymmetric flow and vorticity fields and thus asymmetric pressure field. It increases the asymmetry of force on the pipe and thus develops large downward fluid force. Both of them are the causes of selfburying of the pipeline with spoiler.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.107-108
• /
• 2007

Overhead transmission lines are completely exposed to the environment. This causes faults in transmission lines due to natural environmental conditions. In some cases, transmission towers are damaged by typhoons and snow, as well as sleet on the transmission lines. It takes a lot of time to repair the damaged towers. For emergency restoration purposes, steel poles are installed to temporarily supply power. Before 2003, emergency restoration steel poles were made of angled steel, which required a large number of beams, bolts, etc. In addition, the foundation of the steel pole and ground wire was constructed using excavation and burial methods, therefore it required a lot of manpower and time to construct temporary transmission lines. In September 2003, typhoon Maemi, whose maximum wind speed was 60m/s, hit Korea. 'Maemi' destroyed transmission lines in the Busan and Geojea area, causing long blackouts. To reduce the recovery time to the damaged transmission lines, self-build based emergency towers were developed. self-build based emergency towers reduced recovery time from 24 hours to 4 hours or less. However, the self-build based emergency tower had no arms, so the temporary transmission lines could only be constructed without curves in line routes. In this paper, solving these self-build based emergency tower limitations, using insulated arms(designed for use with the self-build based emergency tower), shall be explained.

• Geophysics and Geophysical Exploration
• /
• v.21 no.4
• /
• pp.244-254
• /
• 2018

The first geophysical technique applied to the agricultural sector in Korea was electrical resistivity sounding and conducted in purpose of groundwater exploitation in the 1970s. According to the diversity of agricultural activities since the 1990s, various geophysical methods including electrical resistivity, electromagnetic induction, and self-potential method were applied to several agricultural fields such as soil characterization with saline concentration in vast reclaimed area, delineation of seawater intrusion regions in costal aquifer, safety inspection of embankment dikes with leakage problem, detection of ground subsidence from overpumping and tracing of groundwater aquifer contamination by leachate from livestock mortality burial or waste burial site. This paper introduces representative geophysical techniques that have been utilized in various agricultural fields and suggests several ways to develop the geophysical methods required for the precision agriculture field in the near future based on the past achievements.

• Journal of Internet of Things and Convergence
• /
• v.8 no.1
• /
• pp.17-22
• /
• 2022

This paper is a study on the self-powered wireless bus information and disaster information system based on Internet of Things (IoT). The existing bus information system supplies power and communication by cable, which causes a problem of increased installation cost and limited installation site due to cable burial. To solve this problem, a self-powered wireless bus information and disaster information system was proposed. The proposed system provides bus arrival information. Furthermore, in the event of a disaster such as a natural disaster, it can also reduce confusion and damage by notifying the disaster information through the system's speaker. In this study, a self-powered system using a solar module was proposed. As data are transmitted and received through wireless WiFi or LTE, the installation cost can be reduced and the problem of installation location restrictions can be solved.

• Journal of English Language & Literature
• /
• v.58 no.1
• /
• pp.21-42
• /
• 2012

Gloria Naylor's second novel Linden Hills (1985) explores the issues of self-exploration, empowerment, history, and memory by delineating the communal and familial tragedies and the distortion of values prevalent in a prosperous African-American urban community called Linden Hills. Drawing upon the Freud's concept of "primal scene" and "family romance," this paper aims to focus upon the Nedeed family, the founder of Linden Hills, and investigate the compelling traumatogenic force within the family, which is inseparably intertwined with the inversion of values and moral corruption permeating the entire community. The "primal crime" committed by the Nedeed ancestors serves to preserve and perpetuate a tyrannical rule by ruthless patriarchs who reign by underhanded strategies of purposefully neglecting and abusing others, including their own wives. The imprisonment, by Luther Nedeed, of his wife Willa in the family morgue epitomizes the long legacy running in the family-the oppression and burial of the pre-Oedipal, maternal history. Willa's accidental encounter, at the nadir of the family estate and her personal despair, with the faded records of the forgotten and abused Nedeed women exposes the violence-ridden ground of the family's primal scene and the absurdity of family romance the Nedeeds pursued. As the several lines of poem composed by Willie, Willa's male double, show, the hidden, forgotten history of the Nedeed women, in a sense, is the real, which cannot be assimilated to the social symbolic governed by the inhumane patriarchy of the Nedeed family and the success-oriented Linden Hills society. By portraying a catastrophic downfall of the Nedeed family and the futile outcome of its family romance, the ending of Linden Hills conveys implicitly that the contingent symbolic order and its oppressive control, however solid and invincible they may seem, can be toppled down by the real, its nameless forgotten Other.

• The Korean Journal of Community Living Science
• /
• v.25 no.3
• /
• pp.401-415
• /
• 2014

To prepare for the changes in the future, this study considered people in their seventies and eighties in rural areas in the last decade. Based on a survey of rural life by the Rural Development Administration, all factors were analyzed using SAS ver. 9.3. The rate of rice farming decreased, and vegetable-cultivation increased from 8.4% in 2001 to and 26.6% in 2008 for people in their seventies and eighties. The number of family members decreased to 1.96 in 2010 from 2.04 in 2001, and annual income increased by KRW 20-29 million for those in their seventies and eighties, whereas it was more than KRW 30 million for those in their forties. Bathing with warm water increased to 88.9% from 69.8%, and household waste treated by self-incineration decreased from 86.4% to 40.0% in the last decade. Separate collection spread since 2008. Food waste disposal and the burial (46.0%) showed had for people in their seventies and eighties, and animal feed increased (50.7%) for those in their forties at 2001. The separate collection increased by 39.6% in 2010 for those in their seventies and eighties and by 53.5% for those in their forties(p<0.05). The manufacture of jang and kimchi showed were little annual changes for people in their seventies and eighties. Food storage processing was higher for those in their forties. For those in their seventies and eighties, food group intake over the 2004-2010 period increased from 3.3 times a week to 4.2 times a week for protein foods and from 4.9 times a week to 5.5 times a week for vegetables. There was no change in fruits, milk, and seaweeds for those in their seventies and eighties, but there was an increase for those in their forties. The results suggest the continued increase in the manufacture of jang and kimchi and protein and vegetable intake for those in their seventies and eighties. Some direction to welfare, mechanized rice planting and living with neighbors together would be continued with good nutrition for elderly residents.

• The Korean Journal of Community Living Science
• /
• v.25 no.1
• /
• pp.99-111
• /
• 2014

To verify welfare needs, rural health and environmental factors were compared between agricultural and nonagricultural groups over the past 10 years. Based on a survey of rural life by the Rural Development Administration, whose sample included agricultural (72.8%) and nonagricultural (27.2%) groups, all factors were analyzed using SAS ( 9.3). For rural home heating, the use of oil boilers (77.2%-78.0%) decreased (53.0%-53.7%) over the same period, whereas that of electric boilers increased (21.9% and 13.5% for agricultural and nonagricultural groups, respectively). The joint water- supply increased, and the use of flush toilets (52.4% to 84.5% in the agricultural group and 64.6% to 81.4% in the nonagricultural group) and hot-water bathing was higher in the agricultural group (79% to 92.6%) than in the nonagricultural group (72.2% to 87.6%) at the p<0.001 level. Incineration accounted for the largest portion of household waste until 2006, when it was replaced by other treatment methods such as the pay-per-treatment option (44.4% and 68.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). Garbage disposal in 2001 was mainly burial or animal feed, but separate collection increased in 2010 (42.2% and 64.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). The self-perception of health was lower in the agricultural group than in the nonagricultural group (2.96 to 2.74 on a five-point scale in the agricultural group and 3.07 to 2.98 in the nonagricultural group). Drinking decreased less in the agricultural group (criteria: one point once a week,; 1.48 to 1.20) than in the nonagricultural group (1.13 to 0.80) at p<0.001, and a similar pattern was found for smoking (p<0.001). Health screening decreased in the last 10 years (scoring based one point/1-2 times per year,: 0.94 to 0.64 in the agricultural group and 1.08 to 0.69 in the nonagricultural group;p<0.01). These results indicate that various health and environmental factors were less favorable to farmers except for bathing in comparison to nonagricultural living in the same area. This suggests that people in agriculture are less likely to live and work in favorable environments than those outside the sector and thus indicates a need for more attention to the national health welfare system for farmers for systematic realization.