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Bearing Capacity Analyses of Shallow Foundations in Reinforced Slopes

  • Kim, Hong-Taek;Choi, In-Sik;Sim, Young-Jong
    • Geotechnical Engineering
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    • v.12 no.3
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    • pp.127-148
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    • 1996
  • Recently, foundations of heavy structures such as bridge abutments have been built on slopes or near the crest of slopes at an increasing rate. Because the bearing capacity of such foundations is considerably lower than the bearing capacity of the same soil on a level ground, deep footings such as piles and caissons are often used. However, the costs of such methods are generally very high. One of the new techniques to overcome the problem is to place reinforcing members such as geosynthetics or metal strips horizontally at some depths beneath the footings. Rational methods of analysis to predict the bearing capacity of footings in reinforced slopes are therefore needed. This paper proposes an analytical method for estimating the increase in bearing capacity gained from the included horizontal strips or ties of tensile reinforcing in the foundation soil below the footing built near the crest of a slope. A failure mechanism, including the concept of'wide slab effect', adopted in the present study for analyzing the bearing capacity of foundations in reinforced slopes, is established through the observed model test behaviors described by Binquet SE Lee and Huang et al, and the Boussinesq solutions. The analytical results are then compared with the experimental data described in the paper by Huang et al. Also in order to properly evaluate the soil reinforcement interaction, typical pullout test values of the apparent friction coefficient, which usually vary with depths owing to both the increase of the shearing volume and the increase in local stress caused by soil dilatancy, are analyzed and related functionally. Furthermore, analytical parametric studies are carried out to investigate the effect and significance of various pertinent parameters associated with design of reinforced slope foundations. Keywords : Bearing capacity, Reinforced slope, Slab effect, Friction coefficient.

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A Study on Pseudolite-augmented Positioning Method for Automatic Docking (자동접안을 위한 의사위성 보강 측위기법에 관한 연구)

  • Park, Sang-Hyun;Cho, Deuk-Jae;Oh, Se-Woong
    • Journal of Navigation and Port Research
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    • v.30 no.10 s.116
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    • pp.839-845
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    • 2006
  • A laser docking system provides a centimeter-level accuracy distance from jetty mounted laser sensors in order to help a vessel to approach to a pier. It is very accurate & useful, whereas there are too many considerable problems. Laser sensors of the laser docking system need to be correctly positioned and installed on a jetty to allow for full range of vessels to be berthed and to consider loading condition and tidal variations. Above all, the laser docking system is expensive and its service coverage is limited. In order to solve these problems, CDGPS positioning method using GPS satellites has been proposed. This paper presents that, through RHDOP simulation, the previous CDGPS positioning method using only GPS satellites is not able to provide the continuous service with centimeter-level positioning accuracy. And this paper proposes a pseudolite-augmented positioning method for vessel docking in order to solve the problem of the continuous service on the previous CDGPS positioning method. In this paper, pseudolite is used to aid in CDGPS positioning. This paper shows that the proposed method can provides the continuous service through comparison analysis of RHDOP simulation results between the GPS satellite constellation and the pseudolite-augmented GPS satellite constellation. Furthermore, it is shown that the proposed positioning method satisfies the positioning performance required for vessel automatic docking at a test bed designed for performance evaluation.

Selection of Retaining Wall System for Underground Parking Lots Expansion of Apartments (거주중 공동주택의 지하주차장확대를 위한 흙막이공법 선정)

  • Ro, Young-Chang;Lee, Chan-Sik
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.2
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    • pp.99-107
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    • 2008
  • Rapidly increasing automobile supply rate according to improved economic level of life makes lack of parking space of apartments. Even though the initial design of parking space compiled with old regulations, it may not observe either new laws or requirement of inhabitants. Even if old apartments have no structural durability problem, outworn facilities and insufficient parking area may be a main reason for reconstruction. It causes waste of national resources and makes recycling issues. Additionally, irregularly parked cars make traffic obstruction to a fire engine and result in many fire accident victims. Parking problems of apartments are not only inconvenience but also serious safety issues. From these points of view, remodeling only for parking area expansion is necessary to avoid overall reconstruction of apartments. The purpose of this study is to suggest a retaining wall selection method for apartments underground parking lots expansion without evacuation of resident people. Effect factors to select retaining wall system are analyzed and weight values are calculated by applying AHP. One selection method of retaining wall is proposed by evaluating applicability and its sensitivity analysis is executed. This selection method is expected to help decision-making of retaining wall system selection.

Purification and Identification of Apoptosis Modulator Pipernonaline from Piper longum Linn. against Prostate Cancer Cells (필발(Piper longum Linn.)로부터 전립선암 세포사멸물질 pipernonaline의 분리 및 동정)

  • Kim, Kwang-Youn;Kim, Yun-Jin;Lee, Wan;Yu, Sun-Nyoung;Cho, Hyo-Jin;Lee, Sun-Yi;Lee, Han-Seung;Sohn, Jae-Hak;Oh, Hyuncheol;Ahn, Soon-Cheol
    • Journal of Life Science
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    • v.19 no.5
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    • pp.671-675
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    • 2009
  • Prostate cancer has been a critical health problem due to an increase of prostate cancer-related deaths worldwide. Also, a frequent treatment option for prostate cancer is androgen ablation, but this treatment has a limited scope, especially for hormone-refractory cancer. There is an urgent need for the identification of alternative therapeutic strategies for prostate cancer. Previously, over one hundred species of dried-plant methanol extracts were tested for inhibitory effects on proliferation. One of them, Piper longum Linn. was selected based on its potent anti-proliferation effect. The dried root of P. longum Linn. was extracted with 100% methanol for 2-3 days and its extract was fractionated using chloroform. The chloroform layer was then subjected to column chromatography on silica gel, reverse phase-18 (RP-18) and Sephadex LH-20, in turn. Finally, the pure compound was obtained and identified as pipernonaline by NMR spectroscopic and physico-chemical analysis. In this study, anti-proliferation and cell cycle arrest effects of pipernonaline on human prostate cancer PC-3 cells were investigated using the MTT and PI staining, respectively. Our findings suggest that pipernonaline represents a dose-dependent growth inhibition pattern on PC-3 cells and, moreover, its growth inhibition is associated with sub-G1 and G0/G1 cell cycle accumulation in PC-3 cells. Also, these results provide an anticancer candidate for human prostate cancer.

Factors affecting the turnover intention of Industrial Accident Hospital Employees by Job Category (산재병원 구성원들의 직종별 이직의사에 관련된 영향요인)

  • Bang, Yong-Joo
    • Korea Journal of Hospital Management
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    • v.8 no.3
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    • pp.92-117
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    • 2003
  • The purpose of this study was to analyze the characteristics of socio-demographic, organizational conflict and job satisfaction, and to examine the interrelation of influential factors in the intention of turnover. The data for this study were collected through a self-administrated survey with a structured questionnaire to 1,027 subjects from several medical doctor staff members, nursing staff members, administration staff members, pharmacist, and technical expert of eleven hospitals. The data were collected by self-reporting questionnaire from July 29 to September 7, 2002. In this analysis frequency test, t-test, ANOVA, multiple regression were used. The main results of this research is as following; 1. According to socio-demographic characteristics of the respondent's level of the intention of turnover was higher in a doctor staff members than others, for females than males, and had worked for 5-10 years in hospitals. Also, the intent to turnover was generally higher younger workers than long terms workers. 2. According to the organizational conflict characteristics as the respondents who got less conflict experience in the organization, their level of the intention of turnover was higher. And, technical conflict experiences were expressed greater than hierarchical conflict experiences. 3. According to the job satisfaction characteristics as his or her satisfaction that is about the promotion, working itself, salary, and fellowship in the organizational was higher, the level of the intention of turnover was lower. 4. According to the result of Multiple Regression for the doctor staff members in general hospitals rather than special hospitals was negatively correlated with the satisfaction of working itself while hierarchical conflict factors in the organizational conflict characteristics was positively correlated with the intention of turnover. For the nursing staff members the job satisfaction for the working itself, salary were negatively correlated with the intention of turnover. For the administration staff members as the job satisfaction for the working itself was negatively correlated with the intention of turnover. For medical and pharmacy staff members as more working experience, correlation with the intention of turnover was negative. Besides, as the job satisfaction for the working itself and the fellowship was negatively correlated with the intention of turnover. For the skill and technicians, the job satisfaction for the working itself, promotion were negatively correlated with the intention of turnover. The above indicate that job satisfaction and promote their ability and form a good relationship with organization members were very important to decrease the intention of turnover. This study identified the major effective factors of the intention of turnover and analyzed the differences among the job category. In that respect, it is significant for the study to be able to provide a reference for managing hospital of industrial accident and organizational development. However, this study has a problem, which is not to identify a valuable model for examining the relationship between organizational factors such as organizational conflict, job satisfaction, and intention of turnover. Therefore, further study is needed and strengthened in the field of intention of turnover for hospital for industrial accident.

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The Evaluation of an additional Weight Shoe's Function developed for the Improvement of Aerobic Capacity (유산소 운동능력 향상을 위한 중량물 부가 신발의 기능성 평가)

  • Kwak, Chang-Soo;Kim, Hee-Suk
    • Korean Journal of Applied Biomechanics
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    • v.14 no.3
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    • pp.67-82
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    • 2004
  • The purpose of this study was to evaluate the function and the safety of an additional weight shoe developed for the improvement of aerobic capacity, and to improve some problems found by subject's test for an additional weight shoe. The subjects employed for this study were 10 college students. 4 video cameras, AMTI force platform and Pedar insole pressure distribution measurement device were used to analyze foot motions. The results of the study were as follows: 1 The initial achilles tendon angle and initial rearfoot pronation angle of an additional weight shoe during walking were 183.7 deg and 2.33 deg, respectively, and smaller than a barefoot condition. Maximum achilles tendon angle and the angular displacement of achilles tendon angle were 185.35 deg and 4.21 deg respectively, and smaller than barefoot condition. Thus rearfoot stability variables were within the permission value for safety. 2. Maximal anterior posterior ground reaction force of additional weight shoe was appeared to be 1.01-1.2 B.W., and was bigger than a barefoot condition. The time to MAPGRF of an additional weight shoe was longer than a barefoot condition. Maximal vertical ground reaction force of additional weight shoe was appeared to be 2.3-2.7 B.W., and was bigger than a barefoot condition in propulsive force region. But A barefoot condition was bigger in braking force region. The time to MVGRF of an additional weight shoe was longer than a barefoot condition. 3. Regional peak pressure was bigger in medial region than in lateral region in contrast to conventional running shoes. The instant of regional peak pressure was M1-M2-M7-M4-M6-M5 -M3, and differed form conventional running shoes. Regional Impulse was shown to be abnormal patterns. There were no evidences that an additional weight shoe would have function and safety problems through the analysis of rearfoot control and ground reaction force during walking. However, There appeared to have small problem in pressure distribution. It was considered that it would be possible to redesign the inner geometry. This study could not find out safety on human body and exercise effects because of short term research period. Therefore long term study on subject's test would be necessary in the future study.

Impacts of Immigrant Workers on Regional Economy in S. Korea (이주노동자의 유입이 지역경제에 미치는 영향)

  • Choi, Byung-Doo
    • Journal of the Korean association of regional geographers
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    • v.15 no.3
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    • pp.369-392
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    • 2009
  • Recently international movements of labour as well as those of goods and other production elements such as capitals and technology have been increased rapidly under the process of glocalization. The huge amount of immigrant workers' in-flows makes increasing influences on regional economy in South Korea. This paper examines such impacts of immigrant workers on local labor markets, productivity. and industrial composition and innovation on the basis of analysis of empirical data and review of existing literature on the subject. Despite a problem of simplification, some reasoning can be listed as follows: First of all, the inflow of immigrant workers has an effect of job displacement among domestic simple workers, with duel effects on the status of native workers; secondly, Immigrant workers give a positive effect on local productivity, but only with low level of wage and of purchasing power; thirdly, the in-flow of immigrant workers seems to prevent existing industries from transformation towards new ones and/or from automation and innovation of production facilities, while there seems no clear relationship with foreign direct investments of local firms.

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QTL Mapping of Resistance to Gray Leaf Spot in Ryegrass: Consistency of QTL between Two Mapping Populations

  • Curley, J.;Chakraborty, N.;Chang, S.;Jung, G.
    • Asian Journal of Turfgrass Science
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    • v.22 no.1
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    • pp.85-100
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    • 2008
  • Gray leaf spot (GLS) is a serious fungal disease caused by Pyricularia oryzae Cavara, recently reported on the important turf and forage species, perennial ryegrass (Lolium perenneL.). This fungus also causes rice blast, which is usually controlled by host resistance, but durability of resistance is a problem. Few instances of GLS resistance have been reported in perennial ryegrass. However, two major QTL for GLS resistance have been detected on linkage groups 3 and 6 in an Italian x perennial ryegrass mapping population. To confirm that those QTL are still detectable in the next generation and can function in a different genetic background, a resistant segregant from this population has been crossed with an unrelated susceptible perennial clone, to form a new mapping population segregating for GLS resistance. QTL analysis has been performed in the new population, using two different ryegrass field isolates and RAPD, RFLP, and SSR marker-based linkage maps for each parent. Results indicate the previously identified QTL on linkage group 3 is still significant in the new population, with LOD and percent of phenotypic variance explained ranging from 2.0 to 3.5 and 5% to 10%, respectively. Also two QTL were detected in the susceptible parent, with similar LOD and phenotypic variance explained. Although the linkage group 6 QTL was not detected, the major QTL on linkage group 3 appears to beconfirmed. These results will add to our understanding of the genetic architecture of GLS resistance in ryegrass, which will facilitate its use in perennial ryegrass breeding programs.

Influences of Addition of Jellyfish Powder to Bed Soil and Bacterial Community Structure of Bed Soil (해파리 분말의 상토 첨가물로서의 효과 및 상토의 미생물 군집 변화에 대한 연구)

  • Beck, Bo-Ram;Choi, Jae-Ho;Kim, Young-Rok;Cha, Ha-Eun;Do, Hyung-Ki;Hwang, Cher-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.2
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    • pp.227-234
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    • 2012
  • Recently, the population of toxic and/or unusable jellyfish is increasing during summer along the east coast of Korea, causing massive economical and ecological damage to fisheries, nuclear power plant and marine environment. To solve this problem, this study was carried out using jellyfish as a potential soil additive for horticulture. The jellyfish was solidified and homogenized, then mixed with a commercial bed soil. Allium tuberosum ROTH was planted to control bed soil (BS) and jellyfish powder mixed bed soil groups (Mixed bed soil, MBS), and following parameters were measured during five weeks: water content, electrical conductivity and growth of leaves. At the end of the experiment, bacterial community structures of each pot were analyzed by DGGE. The relative water adsorption of jellyfish powder was about 2.5 times greater compared to its dry weight. The water content of MBS group was significantly higher than BS group 6.5 to 14.2%, and the electric conductivity of MBS group was measured around 2.8 dS/m where BS group was resulted average of 1.8 dS/m. However, the leaves of BS group were grown 30% longer compared to MBS group. DGGE analysis of MBS group was shown in high number of phylum Bacteroidetes and increased diversity of Sphingobacteriia compared to BS group. Jellyfish powder as a soil additive surely will be a good candidate as humectant and microbiota stimulator, although there are several obstacles such as high electrical conductivity and residual alum salt which used for solidification of jellyfish.

Determination of Exchangeable Cations in Soils Affected by Different Types of Salt Accumulation (염류집적 유형이 다른 토양의 교환성 양이온 측정)

  • Lee, Ye-Jin;Yun, Hong-Bae;Kim, Rog-Young;Lee, Jong-Sik;Song, Yo-Sung;Sung, Jwa-Kyung;Yang, Jae-E.
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.2
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    • pp.135-142
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    • 2012
  • Exchangeable cations are often overestimated especially in salt-affected soils due to the presence of high levels of soluble ions in soil solution. Thus, quantitative analysis of the soil exchangeable cation based on ammonium acetate extraction method {(Exch. Cation)$_{total}$} requires additional process to remove the free ions (pre-washing) in soil with distilled water or alcohol {(Exch. Cation)$_{pw}$} or subtraction of the soluble ion contents from the total exchangeable cations {(Exch. Cation)$_{ref}$}. In this research, we compared the three different methods for the determination of exchangeable cations in soils affected by different types of salt accumulation such as the soils from upland, plastic film house, and reclaimed tidal land. In upland soils, non-saline and non-sodic soils, the regular ammonium acetate extraction method did not have any problem to determine the content of exchangeable cations without any additional process such as the pre-washing method or the subtraction method. However, the contents of exchangeable cations in the salt-affected soils might be determined better with the pre-washing method for the plastic film house soils and with the subtraction method for the reclaimed tidal land soils containing high Na.