• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.4
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• pp.295-306
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• 2010

Contrary to an intact rock, the jointed rock mass shows strain-dependent deformation characteristics (elastic modulus and damping ratio). The maximum elastic modulus of a rock mass can be obtained from an elastic wave-based exploration in a small strain level and applied to seismic analyses. However, the assessment and application of the non-linear characteristics of rock masses in a small to medium strain level ($10^{-4}{\sim}0.5%$) have not been carried out yet. A non-linear dynamic analysis module is newly developed for FLAC3D to simulate strain-dependent shear modulus degradation and damping ratio amplification characteristics. The developed module is verified by analyzing the change of the Ricker wave propagation. Strain-dependent non-linear characteristics are obtained from disks of cored samples using a rock mass dynamic testing apparatus which can evaluate wave propagation characteristics in a jointed rock column. Using the experimental results and the developed non-linear dynamic module, seismic analyses are performed for the intersection of a shaft and an inclined tunnel. The numerical results show that vertical and horizontal displacements of non-linear analyses are larger than those of linear analyses. Also, non-linear analyses induce bigger bending compressive stresses acting on the lining. The bending compressive stress concentrates at the intersection part. The fundamental understanding of a strain-dependent jointed rock mass behavior is achieved in this study and the analytical procedure suggested can be effectively applied to field designs and analyses.

• Education of Primary School Mathematics
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• v.26 no.4
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• pp.277-298
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• 2023

Despite the significance of teacher guidebooks as a support for teacher learning, there are few studies that address the educative features of teacher guidebooks. The purpose of this study is to develop a framework for analyzing the educative features of teacher guidebooks for elementary school mathematics. The framework developed by Fuentes and Ma(2018) for analyzing teacher guidebooks, "Teacher Learning Opportunities in Mathematics Curriculum Materials", was used as an initial framework by adding the unit development flow that reflects on the organizational features of teacher guidebooks in Korea for elementary mathematics. Then, the framework was modified and supplemented by testing 10 types of teacher guidebooks for Grades 3 and 4 per six units reflecting on different mathematical strands. As a result, the final framework expanded the initial framework and added elements related to each dimension of the framework according to the unit development flow. The analytical framework developed in this study can be used to closely analyze the educative features of teacher guidebooks of Korean elementary school mathematics in the future and to develop teacher guidebooks to promote teacher learning.

• Computers and Concrete
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• v.33 no.5
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• pp.497-507
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• 2024

In squat reinforced concrete walls, the displacement capacity for lateral deformation is low and the ability to resist the axial load can quickly be lost, generating collapse. This work consists of testing two squat reinforced concrete walls. One of the specimens is built with conventional detailing of reinforced concrete walls, while the second specimen is built applying an alternative design, including stirrups along the diagonal of the wall to improve its ductility. This solution differs from the detailing of beams or coupling elements that suggest building elements equivalent to columns located diagonally in the element. The dimensions of both specimens correspond to a wall with a low aspect ratio (1:1), where the height and length of the specimen are 1.4 m, with a thickness of 120 mm. The alternative wall included stirrups placed diagonally covering approximately 25% of the diagonal strut of the wall with alternative detailing. The walls were tested under a constant axial load of 0.1f'cAg and a cyclic lateral displacement was applied in the upper part of the wall. The results indicate that the lateral strength is almost identical between both specimens. On the other hand, the lateral displacement capacity increased by 25% with the alternative detailing, but it was also able to maintain the 3 complete hysteretic cycles up to a drift of 2.5%, reaching longitudinal reinforcement fracture, while the base specimen only reached the first cycle of 2% with rapid degradation due to failure of the diagonal compression strut. The alternative design also allows 46% more energy dissipation than the conventional design. A model was used to capture the global response, correctly representing the observed behavior. A parametric study with the model, varying the reinforcement amount and aspect ratio, was performed, indicating that the effectiveness of the alternative detailing can double de drift capacity for the case with a low aspect ratio (1.1) and a large longitudinal steel amount (1% in the web, 5% in the boundary), which decreases with lower amounts of longitudinal reinforcement and with the increment of aspect ratio, indicating that the alternative detailing approach is reasonable for walls with an aspect ratio up to 2, especially if the amount of longitudinal reinforcement is high.

• Sim-seong Yeon-gu
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• v.33 no.1
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• pp.61-80
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• 2018

We investigated whether the 81 items of the Gray-Wheelwright test correctly measure the concept of Jung's typology and aimed to refine the test. Participants (n=431) completed the Gray-Wheelwright test, and the results were analyzed using factor analysis with the varimax rotation and the maximum likelihood extraction method. A pair of opposing attitudes, introversion/extroversion, or one of the two pairs of opposing functional types, thinking/feeling or intuition/sensation, was labeled to the extracted factor according to the majority type of the items in the factor. The minority items or items not included in any factors were excluded from making a short form of the Gray-Wheelwright test with 45 items. We used intraclass correlation (ICC) coefficient and Cronbach's alpha for the test-retest reliability and internal consistency of the test, respectively. The newly developed short form of the Gray-Wheelwright test measured the Jung's personality types well, which was comparable to the original one while reducing time and effort required for the testing.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.92-97
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• 1994

An attempt was made to provide the most resonable fertilizer recommendation for sesame and peanut crops based on soil analytical data and yield response to the NPK fertilizer application, which were obtained from field experiments conducted during 1970 to 1993. 1. According to the analytical data of sesame and peanut soils obtained in 1985~1993, the contents of organic matter, available $P_2O_5$, exchangeable K, Ca and Mg were increased in sesame soils, but the those components were decreased in peanut soils. 2. The yield index of the plot without N, $P_2O_5$ and $K_2O$ fertilizer were 81-84, 84~92 and 81~92, respectively, as the yield of NPK plot was regarded as 100. 3. Linear or quadratic equations derived from the relationship between soil analysis data and fertilizer application rates were proposed for NPK recommendation. The parameters of soil analysis used in the equations for N, P and K were organic matter, available $P_2O_5$ and exchangeable K, respectively. 4. Revised fertilizer recommendation based on the soil chemical status enable to save the fertilizer application of sesame and peanut soils. The amounts of saved NPK fertilizers were 5.1kg N/10a(increase in 2.8kg N/10a for peanut), 0.9~2.9kg $P_2O_5/10a$, and 1.7~5.8kg $K_2O$/10a.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.158-167
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• 2016

The requirements for medical laboratories ISO 15189 is examined in organization and a quality management system, stressing the importance of evidence, document control, and control of records and clinical material. Medical services are provided from the areas of resource management, and pre-examination, examination and post-examination processes. The main goal of ISO 15189 accreditation is to improve the quality of laboratory services provided for patients and clinical users not only through compliance with consensually developed and harmonized requirements but also by adopting the philosophy of continual improvement using the Plan-Do-Check-Act cycle. Laboratory quality should be evaluated and improved in all steps of the testing process as the state-of-the art indicates that the pre- and post-analytical phases are more vulnerable to errors than the intra-analytical phase. The Korea Laboratory Accreditation Scheme (KOLAS), a national accreditation body, provides medical laboratory accreditations for appropriate approaches to evaluating the competence of a medical laboratory in providing effective services to its customers and clinical users. Adoption of ISO 15189 in 2010s as a government policy has been delayed, and only 5 laboratories have been accredited to date in Korea. The medical laboratories should seek the adoption of ISO 15189 with a positive attitude for quality improvement and strengthening of international competitiveness.

• Analytical Science and Technology
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• v.20 no.5
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• pp.434-441
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• 2007

The aim of this paper is to investigate composition of fatty acids in sweat on purpose of latent fingerprint detectant developing and crime evidence searching. Fingerprint from 5 male donors (aged 29-50 years) were collected. We identified fatty acid components on sweat using methylester mixture (37species) as standard fatty acid and analyzed them by GC-FID. As donor was aged, the level of total fat was found to decrease markedly (aged 20-30 years: 56.4-72.0 %, aged 50 years : 32.4-45.4 %). We identifided 28 species fatty acid, primarilly C16:0(palmitic acid), C16:1 (palmitoleic acid), C18:1n9c(oleic acid), C18:0 (stearic acid), C14:0 (tetradecanoic acid) and all sweats were found to contain C12:0 (lauric acid), C15:0 (pentadecanoic acid), C18:2n6c (linoleic acid), C18:2n6t (linolelaidic acid), C20:0 (arachidic acid), C24:0/C20:5n3 (lignoceric acid/eicosapentaenoic acid), but with differing frequencies and at varying levels. C14:1 (myristoleic acid), C15:1 (pentadecenoic acid), C21:0 (heneicosanoic acid), C22:1n9 (erucic acid) were often observed in sample. Ratio of saturated and unsaturated fatty acid was from 0.94:1 to 2.6:1. And decrease of total fatty acids components caused by loss of saturated fatty acid and monounsaturated fatty acid. In case of sweat amino acids, we detected serine ($0-31.9{\mu}L/mL$), threonine ($0-26.2{\mu}L/mL$), glycine ($0-18.9{\mu}L/mL$) and 20-30 years old, highly protein intake ratio individuals increased (10 times) than 50 years old. We observed greatly individual characterization of amino acid compounds in sweat.

• Analytical Science and Technology
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• v.22 no.4
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• pp.285-292
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• 2009

It has been observed that, after long term storage, some ammunitions are misfired by tamping (combustionstopping) due to aging of the chemicals loaded in the ammunitions. Used in ammunitions are percussion powder which provides the initial energy, igniter which ignites the percussion powder, and a delay system that delays the combustion for a period of time. The percussion powder is loaded first, followed by the igniter and then the delay system, and the ammunitions explode by the energy being transferred in the same order. Tamping occurs by combustion-stopping of the igniter or insufficient energy transfer from the igniter to the delay system or the combustion-stopping of the delay system, which are suspected to be caused by low purity of the components, inappropriate mixing ratio, size distribution of particulate components, type of the binder, blending method, hydrolysis by the humidity penetrated during the long term storage, and chemical changes of the components by high temperature. Goal of this study is to find the causes of the combustion-stopping of the igniter and the delay system of the ammunitions after long term storage. In this study, a method was developed for testing of the combustion-stopping, and the size distributions of the particulate components were analyzed with field-flow fractionation (FFF), and then the mechanism of chemical change during long term storage was investigated by thermal analysis (differential scanning calorimetry), XRD (X-ray diffractometry), and XPS (X-ray photoelectron spectroscopy). For the ignition system, M (metal)-O (oxygen) and M-OH peaks were observed at the oxygen's 1s position in the XPS spectrum. It was also found by XRD that $Fe_3O_4$ was produced. Thus it can be concluded that the combustion-stopping is caused by reduction in energy due to oxidation of the igniter.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.2
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• pp.65-70
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• 2005

Those specifications of the CLIA analytical tolerance limits are consistent with the performance goals in Six Sigma Quality Management. Six sigma analysis determines performance quality from bias and precision statistics. It also shows if the method meets the criteria for the six sigma performance. Performance standards calculates allowable total error from several different criteria. Six sigma means six standard deviations from the target value or mean value and about 3.4 failures per million opportunities for failure. Sigma Quality Level is an indicator of process centering and process variation total error allowable. Tolerance specification is replaced by a Total Error specification, which is a common form of a quality specification for a laboratory test. The CLIA criteria for acceptable performance in proficiency testing events are given in the form of an allowable total error, TEa. Thus there is a published list of TEa specifications for regulated analytes. In terms of TEa, Six Sigma Quality Management sets a precision goal of TEa/6 and an accuracy goal of 1.5 (TEa/6). This concept is based on the proficiency testing specification of target value +/-3s, TEa from reference intervals, biological variation, and peer group median mean surveys. We have found rules to calculate as a fraction of a reference interval and peer group median mean surveys. We studied to develop total error allowable from peer group survey results and CLIA 88 rules in US on 19 items TP, ALB, T.B, ALP, AST, ALT, CL, LD, K, Na, CRE, BUN, T.C, GLU, GGT, CA, phosphorus, UA, TG tests in chematology were follows. Sigma level versus TEa from peer group median mean CV of each item by group mean were assessed by process performance, fitting within six sigma tolerance limits were TP ($6.1{\delta}$/9.3%), ALB ($6.9{\delta}$/11.3%), T.B ($3.4{\delta}$/25.6%), ALP ($6.8{\delta}$/31.5%), AST ($4.5{\delta}$/16.8%), ALT ($1.6{\delta}$/19.3%), CL ($4.6{\delta}$/8.4%), LD ($11.5{\delta}$/20.07%), K ($2.5{\delta}$/0.39mmol/L), Na ($3.6{\delta}$/6.87mmol/L), CRE ($9.9{\delta}$/21.8%), BUN ($4.3{\delta}$/13.3%), UA ($5.9{\delta}$/11.5%), T.C ($2.2{\delta}$/10.7%), GLU ($4.8{\delta}$/10.2%), GGT ($7.5{\delta}$/27.3%), CA ($5.5{\delta}$/0.87mmol/L), IP ($8.5{\delta}$/13.17%), TG ($9.6{\delta}$/17.7%). Peer group survey median CV in Korean External Assessment greater than CLIA criteria were CL (8.45%/5%), BUN (13.3%/9%), CRE (21.8%/15%), T.B (25.6%/20%), and Na (6.87mmol/L/4mmol/L). Peer group survey median CV less than it were as TP (9.3%/10%), AST (16.8%/20%), ALT (19.3%/20%), K (0.39mmol/L/0.5mmol/L), UA (11.5%/17%), Ca (0.87mg/dL1mg/L), TG (17.7%/25%). TEa in 17 items were same one in 14 items with 82.35%. We found out the truth on increasing sigma level due to increased total error allowable, and were sure that the goal of setting total error allowable would affect the evaluation of sigma metrics in the process, if sustaining the same process.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.453-458
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• 2002

In order to search for reliable rapid methods of estimating bacterial counts in pork, this study was tried to measure resazurin reduction time which is simple in experimental method, low in analytical cost, able to estimate bacterial count within short time. The results were summarized as follows; Correlation coefficient between initial bacterial log count(25$^{\circ}C$/72hr, Y) and resazurin reduction time(X) from blue color to pink color during incubation at 25$^{\circ}C$ and 30$^{\circ}C$ was higher than other conditions as -0.95 and -0.94, respectively. Considering correlation coefficient and reduction time, incubation temperature was compatible at 30$^{\circ}C$, and regression equation(RE) was Y = -0.4386X + 7.7870. At a bacterial load of $10^2$cfu/$cm^2$, $10^3$cfu/$cm^2$ and $10^4$cfu/$cm^2$ in pork, reduction time was 13.2hr, 10.9hr and 8.6hr, respectively. Correlation coefficient between initial bacterial log count(30$^{\circ}C$/72hr, Y) and resazurin reduction time(X) from blue color to pink color during incubation at 30$^{\circ}C$ was highest among other conditions as -0.93, and RE was Y = -0.4171X + 7.5540. At a bacterial load of $10^2$cfu/$cm^2$, $10^3cfu/$cm^2$ and $10^4cfu/$cm^2$ in pork, reduction time was 13.3hr, 10.9hr and 8.5hr, respectively. Correlation coefficient between initial bacterial log count(35$^{\circ}C$/72hr, Y) and resazurin reduction time(X) from blue color to pink color during incubation at 30$^{\circ}C$ was highest among other conditions as -0.93, and RE was Y = -0.3514X + 6.7513. At a bacterial load of $10^2$cfu/$cm^2$, $10^3$cfu/$cm^2$ and $10^4$cfu/$cm^2$ in pork, reduction time was 13.5hr, 10.7hr and 7.8hr, respectively.