• Title/Summary/Keyword: 변수 해석

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백악기 미국 걸프만 퇴적층의 지구조적, 퇴적학적, 석유지질학적 고찰 (A Review of Tectonic, Sedinlentologic Framework and Petroleum Geology of the Cretaceous U. S. enlf Coast Sedimentary Sequence)

  • Cheong Dae-Kyo
    • The Korean Journal of Petroleum Geology
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    • v.4 no.1_2 s.5
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    • pp.27-39
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    • 1996
  • In the Cretaceous, the Gulf Coast Basin evolved as a marginal sag basin. Thick clastic and carbonate sequences cover the disturbed and diapirically deformed salt layer. In the Cretaceous the salinities of the Gulf Coast Basin probably matched the Holocene Persian Gulf, as is evidenced by the widespread development of supratidal anhydrite. The major Lower Cretaceous reservoir formations are the Cotton Valley, Hosston, Travis Peak siliciclastics, and Sligo, Trinity (Pine Island, Pearsall, Glen Rose), Edwards, Georgetown/Buda carbonates. Source rocks are down-dip offshore marine shales and marls, and seals are either up-dip shales, dense limestones, or evaporites. During this period, the entire Gulf Basin was a shallow sea which to the end of Cretaceous had been rimmed to the southwest by shallow marine carbonates while fine-grained terrigengus clastics were deposited on the northern and western margins of the basin. The main Upper Cretaceous reservoir groups of the Gulf Coast, which were deposited in the period of a major sea level .rise with the resulting deep water conditions, are Woodbinefruscaloosa sands, Austin chalk and carbonates, Taylor and Navarro sandstones. Source rocks are down-dip offshore shales and seals are up-dip shales. Major trap types of the Lower and Upper Cretaceous include salt-related anticlines from low relief pillows to complex salt diapirs. Growth fault structures with rollover anticlines on downthrown fault blocks are significant Gulf Coast traps. Permeability barriers, up-dip pinch-out sand bodies, and unconformity truncations also play a key role in oil exploration from the Cretaceous Gulf Coast reservoirs. The sedimentary sequences of the major Cretaceous reseuoir rocks are a good match to the regressional phases on the global sea level cuwe, suggesting that the Cretaceous Gulf Coast sedimentary stratigraphy relatively well reflects a response to eustatic sea level change throughout its history. Thus, of the three main factors controlling sedimentation (tectonic subsidence, sediment input, and eustatic sea level change) in the Gulf Coast Basin, sea-level ranks first in the period.

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An Electrical Conductivity Reconstruction for Evaluating Bone Mineral Density : Simulation (골 밀도 평가를 위한 뼈의 전기 전도도 재구성: 시뮬레이션)

  • 최민주;김민찬;강관석;최흥호
    • Journal of Biomedical Engineering Research
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    • v.25 no.4
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    • pp.261-268
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    • 2004
  • Osteoporosis is a clinical condition in which the amount of bone tissue is reduced and the likelihood of fracture is increased. It is known that the electrical property of the bone is related to its density, and, in particular, the electrical resistance of the bone decreases as the bone loss increases. This implies that the electrical property of bone may be an useful parameter to diagnose osteoporosis, provided that it can be readily measured. The study attempted to evaluate the electrical conductivity of bone using a technique of electrical impedance tomography (EIT). It nay not be easy in general to get an EIT for the bone due to the big difference (an order of 2) of electrical properties between the bone and the surrounding soft tissue. In the present study, we took an adaptive mesh regeneration technique originally developed for the detection of two phase boundaries and modified it to be able to reconstruct the electrical conductivity inside the boundary provided that the geometry of the boundary was given. Numerical simulation was carried out for a tibia phantom, circular cylindrical phantom (radius of 40 mm) inside of which there is an ellipsoidal homeogenous tibia bone (short and long radius are 17 mm and 15 mm, respectively) surrounded by the soft tissue. The bone was located in the 15 mm above from the center of the circular cross section of the phantom. The electrical conductivity of the soft tissue was set to be 4 mS/cm and varies from 0.01 to 1 ms/cm for the bone. The simulation considered measurement errors in order to look into its effects. The simulated results showed that, if the measurement error was maintained less than 5 %, the reconstructed electrical conductivity of the bone was within 10 % errors. The accuracy increased with the electrical conductivity of the bone, as expected. This indicates that the present technique provides more accurate information for osteoporotic bones. It should be noted that tile simulation is based on a simple two phase image for the bone and the surrounding soft tissue when its anatomical information is provided. Nevertheless, the study indicates the possibility that the EIT technique may be used as a new means to detect the bone loss leading to osteoporotic fractures.

The Study of Operating Conditions by Establishing Density Currents Generator for Improving of Water Quality on Lake Water - With Focus on DO and Water Temperature - (호소수의 수질개선을 위한 DCG 설치시 운전조건에 관한 연구 - DO와 수온을 중심으로 -)

  • Lee, Young-Shin;Han, Kyung-Hee;Kim, Young-Kyu;An, Hyung-Chul;Shin, Sung-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.4
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    • pp.286-294
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    • 2014
  • The purpose of this study is to investigate the effects of applying density current generator (hereafter referred to as DCG to large lakes on the operating conditions of DCG, de-stratification, water quality improvement and inhibition of algae occurrence. As a result of a survey conducted to derive the optimum operating parameters of DCG in a condition to minimize eco-toxicity, the following conclusions were obtained. During the survey period, a marked stratification appeared in September to October 2011 and May 2012. At this time, the average depth of water to form thermocline was found to be $5{\pm}2$ m, so the location of discharge port for the operation of DCG was determined to be about 5 m below from the surface. To minimize the adverse effects of benthos and obtain the effect of water mixture at the time of water circulation, the mixing ratio of surface water and deep water was designed to be 3:1 by means of ecotoxicological assessment on the DCG operating characteristics. To select the appropriate operating hours for DCG, DCG was operated by 12 hr, 24 hr, 36 hr and 48 hr. As its result, the formation of thermocline did not occur during the operation of 36 hr. Also, It was effected that start reoperating from 3rd day after stop 2days under the condition of operated during 36 hr with calculated power consumption. Under the above conditions, the results of DO and water temperature analysis during the operation of DCG showed that the stratification, which was distinct previously, appeared to be weak, and relatively lower levels than those before operation were found as a result of water quality analysis on COD and chlorophyll-a, which leads to the conclusion that the water body is maintained at a stable condition due to the circulation of water by the occurrence of density current resulting from the operation of DCG.

Yongdam Dam Watershed Flood Simulation Using GPM Satellite Data and KIMSTORM2 Distributed Storm Runoff Model (GPM위성 강우자료와 KIMSTORM2 분포형 유출모형을 이용한 용담댐 유역 홍수모의)

  • KIM, Se-Hoon;KIM, Jin-Uk;CHUNG, Jee-Hun;KIM, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.4
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    • pp.39-58
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    • 2019
  • This study performed the dam watershed storm runoff modeling using GPM(Global Precipitation Measurement) satellite rain and KIMSTORM2(KIneMatic wave STOrm Runoff Model 2) distributed model. For YongdamDam watershed(930㎢), three heavy rain events of 25th August 2014, 11th September 2017, and 26th June 2018 were selected and tested for 4 cases of spatial rainfalls such as (a) Kriging interpolated data using ground observed data at 7 stations, (b) original GPM data, (c) GPM corrected by CM(Conditional Merging), and GPM corrected by GDA(Geographical Differential Analysis). For the 4 kinds of data(Kriging, GPM, CM-GPM, and GDA-GPM), the KIMSTORM2 was calibrated respectively using the observed flood discharges at 3 water level gauge stations(Cheoncheon, Donghyang, and Yongdam) with parameters of initial soil moisture contents, stream Manning's roughness coefficient, and effective hydraulic conductivity. The total average Nash-Sutcliffe efficiency(NSE) for the 3 events and 3 stations was 0.94, 0.90, 0.94, and 0.94, determination coefficient(R2) was 0.96, 0.92, 0.97 and 0.96, the volume conservation index(VCI) was 1.03, 1.01, 1.03 and 1.02 for Kriging, GPM, CM-GPM, and GDA-GPM applications respectively. The CM-GPM and GDA-GPM showed better results than the original GPM application for peak runoff and runoff volume simulations, and they improved NSE, R2, and VCI results.

Experiment of Flexural Behavior of Prestressed Concrete Beams with External Tendons according to Tendon Area and Tendon Force (강선량 및 긴장력에 따른 외부 강선을 가진 PSC 보의 휨거동 실험)

  • Yoo, Sung-Won;Yang, In-Hwan;Suh, Jeong-In
    • Journal of the Korea Concrete Institute
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    • v.21 no.4
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    • pp.513-521
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    • 2009
  • Recently, the externally prestressed unbonded concrete structures are increasingly being built. The mechanical behavior of prestressed concrete beams with external unbonded tendon is different from that of normal bonded PSC beams in that the slip of tendons at deviators and the change of tendon eccentricity occurs as external loads are applied in external unbonded PSC beams. The purpose of the present paper is therefore to evaluate the flexural behavior by performing static flexural test according to tendon area and tendon force. From experimental results, before flexural cracking, there was no difference between external members and bonded members. However, after cracking, yielding load of reinforcement, ultimate load, and the tendon stress of external members was lower than that of bonded members. For the relationship of load-tendon stress, the increasing of tendon strain was inversely proportional to the initial tendon force. However, even if the initial tendon force was large, the tendon strain with small effective stress was smaller than that with large effective stress. The concrete compressive strain was proportional to the effective stress of external tendon. From the comparison between test results and codes, the ACI-318 could not consider the effect of tendon force or effective stress, and especially the results of ACI-318 were very small, so it was very conservative. And the AASHTO 1994 could be influenced on the tendon area, initial force and effective stress, but as it was made on the basis of internal unbonded tendon, its results were much larger than the test results. For this reason, the new correct predict equation of external tendon stress will be needed.

The Leisure Activity and the Degree of Satisfaction for the Life by Aged persons in a Rural Area (일부(一部) 농촌노인(農村老人)의 여가활동(餘暇活動)과 생활만족도(生活滿足度)와 관련성(關聯性))

  • Kim, Jae-Soog;Park, Jong;Ryu, So-Yeon;Lee, Chul-Gab;Kim, Hak-Ryul;Kim, Yang-Ok
    • Journal of agricultural medicine and community health
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    • v.24 no.1
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    • pp.131-143
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    • 1999
  • This study was attempted to find the mutual relationship between leisure activities and life satisfaction by the aged persons in a rural area. The data was obtained by interview with questionnaire and the data from 209 persons aged over 65, residing in Dohwa-myeon and Podu-myeon, Koheung-kun, Chollanam-do were analysed. The survey was carried out from Feb. 16th to May 3rd in 1998 and the results are as follows: 1. The survey showed that the major leisure activities were TV watching followed by talking with friends, club activities, taking a walk, visiting friends' or relatives' home and breeding domestic animals. 2. The types of leisure activities were classified into 8 patterns as active self-enlightenment, passive self-enlightenment, temporal amusements, passive self-activities, cozy introspective activities, friend oriented activities, family oriented activities and religious activities. Among the above 8 patterns active self-enlightenment type contributed most to the life satisfaction. 3. The major factors affecting leisure activities were sex, age, average income, religion and educational status. And the major factors affecting life satisfaction were sex, age average income, educational status and a state of health. In conclusion the more the aged persons participated in leisure activities, the better they felt life satisfaction.

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Shape Scheme and Size Discrete Optimum Design of Plane Steel Trusses Using Improved Genetic Algorithm (개선된 유전자 알고리즘을 이용한 평면 철골트러스의 형상계획 및 단면 이산화 최적설계)

  • Kim, Soo-Won;Yuh, Baeg-Youh;Park, Choon-Wok;Kang, Moon-Myung
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.89-97
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    • 2004
  • The objective of this study is the development of a scheme and discrete optimum design algorithm, which is based on the genetic algorithm. The algorithm can perform both scheme and size optimum designs of plane trusses. The developed Scheme genetic algorithm was implemented in a computer program. For the optimum design, the objective function is the weight of structures and the constraints are limits on loads and serviceability. The basic search method for the optimum design is the genetic algorithm. The algorithm is known to be very efficient for the discrete optimization. However, its application to the complicated structures has been limited because of the extreme time need for a number of structural analyses. This study solves the problem by introducing the size & scheme genetic algorithm operators into the genetic algorithm. The genetic process virtually takes no time. However, the evolutionary process requires a tremendous amount of time for a number of structural analyses. Therefore, the application of the genetic algorithm to the complicated structures is extremely difficult, if not impossible. The scheme genetic algorithm operators was introduced to overcome the problem and to complement the evolutionary process. It is very efficient in the approximate analyses and scheme and size optimization of plane trusses structures and considerably reduces structural analysis time. Scheme and size discrete optimum combined into the genetic algorithm is what makes the practical discrete optimum design of plane fusses structures possible. The efficiency and validity of the developed discrete optimum design algorithm was verified by applying the algorithm to various optimum design examples: plane pratt, howe and warren truss.

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Relationships between Fatty Acids and Tocopherols of Conventional and Genetically Modified Peanut Cultivars Grown in the United States (미국산 전통품종과 유전자 재조합 땅콩품종의 지방산과 토코페롤의 상관관계)

  • Shin, Eui-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.10
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    • pp.1618-1628
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    • 2013
  • Relationships between fatty acids and tocopherols in conventional and genetically modified peanut cultivars were studied by gas chromatography with flame ion detector and high performance liquid chromatography with fluorescence detection. Eight fatty acids and four tocopherol isomers in the sample set were identified and quantified. Oleic acid and linoleic acid are major fatty acids and the ratio of oleic and linoleic acids ranged from 1.11 to 16.26. Tocopherols contents were 6.76 to 12.24 for ${\alpha}$-tocopherol (T), 0.08 to 0.39 for ${\beta}$-T, 5.28 to 15.02 for ${\gamma}$-T, and 0.17 to 1.17 mg/100 g for ${\delta}$-T. Correlation coefficient (r) for fatty acids and tocopherols indicated a strong inverse relationship between oleic & linoleic acids (r=-0.97, P<0.05) and positive relationships between palmitic & linoleic acids (r=0.95, P<0.05) and ${\gamma}$-T & ${\delta}$-T (r=0.83, P<0.05). Principal component analysis (PCA) of fatty acids and tocopherols gave four significant principal components (PCs, with eigenvalues>1), which together account for 85.49% of the total variance in the data set with PC1 and PC2 contributing 45.27% and 21.33% of the total variability, respectively. Eigen analysis of the correlation matrix loadings of the four significant PCs revealed that PC1 was mainly contributed by palmitic, oleic, linoleic, and gondoic acids, while PC2 was by behenic acid, ${\beta}$-T, and ${\gamma}$-T. The score plot generated by PC1-PC2 identified sample clusters in the two spatial planes based on the oleic and linoleic acids. The score plot PC3-PC4 didn't separate sample groups.

Clinical Outcome after Treatment with the First-line Drugs in Patients with Persistent Positive Sputum Smear and Negative Sputum Culture Results (지속적인 객담 도말양성 및 배양음성인 폐결핵환자에서 일차항결핵제로 치료종결한 후의 임상성적)

  • Kwon, Eun-Su;Lee, Jong-Youk
    • Tuberculosis and Respiratory Diseases
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    • v.51 no.4
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    • pp.325-333
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    • 2001
  • Background : This study aimed to estimate the clinical outcome and identify the characteristics of a group of patients with pulmonary tuberculosis who completed anti-tuberculosis therapy with the First-line drugs in spite of having positive smear results with negative sputum culture results over the previous six months. Method : A retrospective chart review of 21 patients who fulfilled the above criteria between 1995 and 1999 was performed. The laboratory data as well as the clinical data of the patients with positive smear results and negative culture results over a six months period were reviewed. Results : The negative conversion of sputum culture results was achieved within $1.3{\pm}1.2$ months and the negative conversion of the sputum smear results was accomplished during $9.5{\pm}3.3$ months. Chest X-rays at 5 months following the institution of anti-tuberculosis therapy from all patients revealed improvements. Four out of 21 patients(19%) relapsed during the follow up, $15.2{\pm}13.4$ months after administering anti-tuberculosis therapy for $13.3{\pm}3.1$ months. Relapses were confirmed from between 3 months and 4 months after the treatment completion. Only one of the four relapses had no past history of anti-tuberculosis therapy and the others had prior treatment twice (p<0.01). The period of anti-tuberculosis treatment was extended to a mean of $4.6{\pm}2.6$ months in 12 patients. However, prolongation of anti-tuberculosis therapy had no affect on the relapse rate (odds ratio, 95% CI 0.18, 2.15). Conclusion : Prolongation of therapy with the First-line drugs is not necessary for patients with persistently positive smear results over 6 months and negative culture results. A patient who has had prior anti-tuberculosis therapy more than twice should be paid the closest attention.

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REE(rare earth element) contents for the Korean ginsengs from three different soils (3 토양에서 채취된 고려 인삼의 희토류 원소 함량)

  • Song, Suck-Hwan;Min, Ell-Sik;Chan, Song-Chae
    • Journal of Ginseng Research
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    • v.32 no.4
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    • pp.357-381
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    • 2008
  • REEs of ginsengs(2, 3, 4 years) from the granite, phyllite and shale areas, Keumsan, are analysed and compared with the their soils. In the weathered soils, high element contents are shown in the LREE of the granite and in the HREE of the phyllite. The granite dominantly show positive correlation relationships. In the field soils, the phyllite are high while the granite are low. Relationships of the contents and correlation relationships can be explained with mineral assemblages and contents within soils, and their solubilities. In the host rocks, high contents are found in the LREE of the granite and HREE of the phyllite. The rocks dominantly show positive relationships. In the ginseng, high contents are shown in the 2 year for the shale and granite, and the 4 year for the phyllite. Element pairs mainly show positive relationships. Comparing of the same ages, the granite are mainly high. In the ratios between the soils and the ginsengs, differences of the several hundred to ten times are found, but dominantly, of the several hundred times in the shale and phyllite, and of the several ten times in the granite. The differences are big in the 3 year, and small in all REE of the 2 year from the shale and granite. while, in the phyllite, big in the LREE of the 2 year and HREE of the 3 year. Based on the absorption of the leachate by the ginsengs within soils, contents and correlation relationships of the ginsengs from the different soils can be explained with mineral assemblages, solubilities of the constitutional minerals and phyio-chemical affects influenced on the solubility. Of the three different soils, the ginsengs of the granites are chemically more similar to their soils.