• The Korean Journal of Zoology
• /
• v.6 no.2
• /
• pp.11-15
• /
• 1963

A total of 220 adult male mice (18-20g) of the S.M. strain were divided into ten experimental and control groups. The total-body X-ray irradiation doses used were 50 r, 100r, 200r, 400r, 600r, 800r, 1,000r, 1,200r, 1,400r, and1,600r. The respiratory arrest (mortality) caused by each irradiation doses were observed for 30 days. Relationships between irradiation doses and survival time and percentage of response were examined. From this experiment, a formula was obtained to express the relationship among three factors, which may be presented as follows : {{{{{{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c) }} {{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c)

• Journal of the Korean Geotechnical Society
• /
• v.31 no.4
• /
• pp.13-18
• /
• 2015

Considering dredged ground is consolidated more than one meter, Compression index prediction is very important. But, UD-sampling and consolidation test are impossible because of high moisture content and weak shear strength. This paper demonstrates the compression index relation, $C_{c(d)}=F(e_d,C_c)$, between in-situ and dredged clay using N. Keith Tovey's Omega point and soil physical properties. Good relationship is confirmed between proposed formula and measured primary consolidation result on dredged ground in The Republic of Korea.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.23 no.3
• /
• pp.88-95
• /
• 1981

This study was carried out to investigate the relation between seepage losses and flow section area in earth canals. Totally 77 seepage measurement was gained by ponded method and the tested canals belong to the irrigation area of Farmland Improvement Association in each province, Korea. The results obtained from this study may be used as a reasonable criteria for the estimation of canal seepage losses in the design of irrigation systems. Obtained results are summarized as follows: 1. Average seepage rates in each Soils is 14cm/day in ML, 6. 3cm/day in CL and 24.9 cm/day in SM. 2. Water depth and water surface width in eath canals have little influenced on the seepage rate, while the seepage losses was increased in proportion as the water surface width lengthens. 3. A formula of S=C.An defining a relationship between seepage losses and flow section was derieved as follows. ML:S=O. 35 VA 1.20 (m$^3$/day/m) CL:S=O. 13 VA 0.84 SM:s=O.67VA-1.56 4. The average seepage loss rates per 1km of canal are as followings. Measured Time ML CL SM 0-4 hrs 2.2% 0.6% 4.5% 4-2 4hrs 1.0% 0.15% 2.0% In above table we may obtain the following results. The first row is suitable for the canal having short delivery time of irrigation, while the second row for the canal having long delivery time.

• Animal cells and systems
• /
• v.4 no.4
• /
• pp.319-324
• /
• 2000

Species boundaries among the Alcyonacean soft coral, the genus Dendronephthya, are often obscured by inter- and intraspecific morphological variations. In the present study, we attempted to infer the genetic relationships of eight dendronephthians based on their molecular characters, the internal transcribed spacer (ITS) regions of ribosomal DNA, and then compared this result together with the random amplified polymorphic DNA (RAPD) data from our previous investigation. Dendronephthya. putteri and D. suensoni formed a divaricate form - VI grade specific clade, whereas D. castanea, D. gigantea, D. aurea and D. spinifera, formed a umbellate and glomerate form - IV and III grade specific clade. Therefore, we confirmed that the main characters the growth form and the anthocodial grade and formula, are important in identification of the species in dendronephthians despite some problems. Also, the relationships of the growth form are clarified as the glomerate form is much closer to the umbellate form than to the divaricate form based on two sets of independent molecular data. However, we cannot determine the molecular markers which limit the species boundaries among this genus with ITS sequences.

• Journal of the Optical Society of Korea
• /
• v.16 no.4
• /
• pp.372-380
• /
• 2012

The optical method Digital Speckle Correlation Measurement (DSCM) has been extensively applied due its capability to measure the entire displacement field over a body surface. A formula of displacement measurement errors by the gradient-based DSCM method was derived. The errors were found to explicitly relate to the image grayscale errors consisting of sub-pixel interpolation algorithm errors, image noise, and subset deformation mismatch at each point of the subset. A power-law dependence of the standard deviation of displacement measurement errors on the subset size was established when the subset deformation was rigid body translation and random image noise was dominant and it was confirmed by both the numerical and experimental results. In a gradient-based algorithm the basic assumption is rigid body translation of the interrogated subsets, however, this is in contradiction to the real circumstances where strains exist. Numerical and experimental results also indicated that, subset shape function mismatch was dominant when the order of the assumed subset shape function was lower than that of the actual subset deformation field and the power-law dependence clearly broke down. The power-law relationship further leads to a simple criterion for choosing a suitable subset size, image quality, sub-pixel algorithm, and subset shape function for DSCM.

• Journal of Soil and Groundwater Environment
• /
• v.25 no.2_spc
• /
• pp.55-69
• /
• 2020

Permeability-analyzing methods commonly involve small-scale drilling, such as pumping or slug test, but it is difficult to identify overall distribution of permeability of the entire target sites due to high cost and time requirement. Spectral induced polarization (SIP) method is known to be capable of providing distributions of both the porosity and the pore size, the two major parameters determining permeability of the porous medium. The relationship between SIP variables and permeability has been studied to identify the hydrological characteristics of target sites. Kozeny-Carman formula has been improved through many experiments to better predict fluid permeability with electrical properties. In this work, the permeability prediction techniques based on SIP data were presented in accordance with the hydrogeological and electrical characteristics of a porous medium. Following the summary of the techniques, various models and related laboratory experiments were analyzed and examined. In addition, the field applicability of the prediction model was evaluated by field case analysis.

• Geomechanics and Engineering
• /
• v.18 no.6
• /
• pp.567-574
• /
• 2019

In order to study the effect of stress and water pressure on the permeability of fractured rock mass under three-dimensional stress conditions, a single fracture triaxial stress-seepage coupling model was established; By using the stress-seepage coupling true triaxial test system, large-scale rock specimens were taken as the research object to carry out the coupling test of stress and seepage, the fitting formula of permeability coefficient was obtained. The influence of three-dimensional stress and water pressure on the permeability coefficient of fractured rock mass was discussed. The results show that the three-dimensional stress and water pressure have a significant effect on the fracture permeability coefficient, showing a negative exponential relationship. Under certain water pressure conditions, the permeability coefficient decreases with the increase of the three-dimensional stress, and the normal principal stress plays a dominant role in the permeability. Under certain stress conditions, the permeability coefficient increases when the water pressure increases. Further analysis shows that when the gob floor rock mass is changed from high stress to unloading state, the seepage characteristics of the cracked channels will be evidently strengthened.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.12
• /
• pp.181-188
• /
• 2019

The maintenance of school building is pivotal issue. However, it is difficult to obtain basic analysis data for LCC(Lifecycle Cost) analysis and maintenance planning of school building. Therefore, this study proposed System Dynamics(SD) techniques to make maintenance decisions for school building. The interaction between the major parameters related to the aging of a building, maintenance activities, and cost were expressed in Causal Loop Diagram. Based on this, the formula for the relationship between causal maps was defined and converted to Stock and Flow Diagram. Through the completed SD model the 50-year plan of 214 educational building were tested by considered in account budget, maintainability, and budget allocation opinions. As a result, the integrated SD model demonstrated that it can support strategic decision making by identifying the status class and LCC behavior of school buildings by scenario. According to the scenario analysis, the rehabilitation action of preventive maintenance that primarily repairs the buildings in condition grade C showed the best performance improvement effect relative to the cost. Therefore, if the proposed SD model is expanded to consider the effects of other educational policies, the crucial performance improvement budget can be estimated in the long-term perspective.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.18 no.4
• /
• pp.53-68
• /
• 2008

We study on the practical privacy-preserving techniques by matrix-based randomization approach. We clearly examine the relationship between the two parameters associated with the measure of privacy breach and the condition number of matrix in order to achieve the optimal transition matrix. We propose a simple formula for efficiently calculating the inverse of transition matrix which are needed in the re-construction process of random substitution algorithm, and deduce some useful connections among standard error and another parameters by obtaining condition numbers according to norms of matrix and the expectation and variance of the transformed data. Moreover we give some experimental results about our theoretical expressions by implementing random substitution algorithm.

• Structural Engineering and Mechanics
• /
• v.77 no.1
• /
• pp.1-17
• /
• 2021

The influence of prestress force on the fundamental frequency and static deflection shape of uncracked Prestressed Concrete (PC) beams with a parabolic bonded tendon was examined in this paper. Due to the conflicts among existing theories, the analytical solutions for properly considering the dynamic and static behavior of these members is not straightforward. A series of experiments were conducted for a total period of approximately 2.5 months on a PC beam made with high strength concrete, subsequently and closely to the 28 days of age of concrete. Specifically, the simply supported PC member was short term subjected to free transverse vibration and three-point bending tests during its early-age. Subsequently, the experimental data were compared with a model that describes the dynamic behavior of PC girders as a combination of two substructures interconnected, i.e., a compressed Euler-Bernoulli beam and a tensioned parabolic cable. It was established that the fundamental frequency of uncracked PC beams with a parabolic bonded tendon is sensitive to the variation of the initial elastic modulus of concrete in the early-age curing. Furthermore, the small variation in experimental frequency with time makes doubtful its use in inverse problem identifications. Conversely, the relationship between prestress force and static deflection shape is well described by the magnification factor formula of the "compression-softening" theory by assuming the variation of the chord elastic modulus of concrete with time.