• Title/Summary/Keyword: L-curve

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Bioequivalence of Two Clarithromycin Tablets (클래리스로마애신 정제의 생물학적 동등성 평가)

  • 김종국;이사원;최하곤;고종호;이미경;김인숙
    • Biomolecules & Therapeutics
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    • v.6 no.2
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    • pp.219-224
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    • 1998
  • The bioequivalence of two clarithromvcin products was evaluated with 16 normal male volunteers (age 23-28 yr, body weight 57.5-75.517g) following single oral dose. Test product was ReYon Clarithromycin tablets (ReYon Pharm. Corp., Korea) and reference product was Klarici $d_{R}$ tablets (Abbott Korea). Both products contain 250 mg of clarithromucin. One tablet of the test or the reference product was administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). The determination of clarithromycin was accomplished using a modified agar well diffusion bioassay. As a result of the assay validation, the quantification of clarithromycin in human serum by this technique was possible down to 0.03$\mu$g/ml using 100$\mu$l of serum. The coefficient of variation (C.V.) was less than 10%. Average drug concentrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products P>0.05); the area under the curve to last sampling time (24 hr) (AU $Co_{24hr}$ (8.10$\pm$ 1.26 vs 8.22$\pm$ 1.627g . hr/ml), AUC from time zero to infinite (AU $Co_{\infty}$) (8.61 $\pm$ 1.28 vs 8.84$\pm$ 1.71 $\mu$g . hr/ml), maximum plasma concentration ( $C_{msx}$) (0.87$\pm$0.22 vs 0.88$\pm$0.19 $\mu$g/ml) and time to maximum plasma concentration ( $T_{max}$) (2.69 $\pm$0.48 vs 2.56$\pm$ 0.51 hr). The differences of mean AU $Co_{24h}$, $C_{msx}$ and $T_{msx}$ between the two products (1.44, 1.39, and 4.65%, respectively) were less than 20%. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $Co_{24hr}$, and $C_{max}$ were more than 0.8 and less than 0.2, respectivly. Although the power for $T_{max}$ was under 0.8, $T_{max}$. of the two products was not significantly different each other (p>0.05). These results suggest that the bioavailability of ReYon Clarithromycin tablets is not significantly different from that of Klarici $d_{R}$ tablets. Therefore, two products are bioequivalent based on the current results. results.sults.sults.s.s.s.s.s.s.s.

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Epidemiological Investigation for Outbreak of Food Poisoning Caused by Bacillus cereus Among the Workers at a Local Company in 2010 (2010년 일개 회사에서 집단발생한 바실루스 세레우스 식중독에 관한 역학조사)

  • Choi, Kum-Bal;Lim, Hyun-Sul;Lee, Kwan;Ha, Gyoung-Yim;Jung, Kwang-Hyun;Sohn, Chang-Kyu
    • Journal of Preventive Medicine and Public Health
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    • v.44 no.2
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    • pp.65-73
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    • 2011
  • Objects: In July 2 2010, a diarrhea outbreak occurred among the workers in a company in Gyeungju city, Korea. An epidemiological investigation was performed to clarify the cause and transmission route of the outbreak. Methods: We conducted a questionnaire survey among 193 persons, and we examined 21 rectal swabs and 6 environmental specimens. We also delegated the Daegu Bukgu public health center to examine 3 food service employees and 5 environmental specimens from the P buffet which served a buffet on June 30. The patient case was defined as a worker of L Corporation and who participated in the company meal service and who had diarrhea more than one time. We also collected the underground water filter of the company on July 23. Results: The attack rate of diarrhea among the employees was 20.3%. The epidemic curve showed that a single exposure peaked on July 1. The relative risk of attendance and non-attendance by date was highest for the lunch of June 30 (35.62; 95% CI, 2.25 to 574.79). There was no specific food that was statistically regarded as the source of the outbreak. $Bacillus$ $cereus$ was cultured from two of the rectal swabs, two of the preserved foods and the underground water filter. We thought the exposure date was lunch of June 30 according the latency period of $B.$ $cereus$. Conclusions: We concluded the route of transmission was infection of dishes, spoons and chopsticks in the lunch buffet of June 30 by the underground water. At the lunch buffet, 50 dishes, 40 spoons, and chopsticks were served as cleaned and wiped with a dishcloth. We thought the underground water contaminated the dishes, spoons, chopsticks and the dishcloth. Those contaminated materials became the cause of this outbreak.

The Hypoglycemic Effect of Saururus chinensis Baill in Animal Models of Diabetes Mellitus

  • Joo, Hee-Jeong;Kang, Ming-Jung;Seo, Tae-Jin;Kim, Hyun-A;Yoo, Sung-Ja;Lee, Soo-Kyung;Lim, Hwa-Jae;Byun, Boo-Hyeong;Kim, Jung-In
    • Food Science and Biotechnology
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    • v.15 no.3
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    • pp.413-417
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    • 2006
  • The purpose of this study was to investigate the hypoglycemic effect of Saururus chinensis Baill in vitro and in vivo. Methanol extract of S. chinensis Baill inhibited yeast ${\alpha}$-glucosidase activity by 49.8%, which was twice as strong as that of acarbose at a concentration of 0.5 mg/mL in vitro. The effect of S. chinensis Baill methanol extract on the postprandial increase in blood glucose levels was studied in streptozotocin-induced diabetic rats using a carbohydrate load test. Oral administration of S. chinensis Baill extract (500 mg/kg) significantly decreased incremental blood glucose levels at 60 and 90 min (p<0.05) after oral ingestion of starch (1 g/kg). The area under the glucose response curve of the S. chinensis Baill group was significantly decreased compared to that of the control group (p<0.05). The effect of prolonged feeding of S. chinensis Baill was studied in an animal model of type 2 diabetes. Three-week-old db/db mice were fed an AIN-93G diet or a diet containing 0.5% S. chinensis Baill extract for 7 weeks after 1 week of adaptation. Plasma glucose, insulin, and blood glycated hemoglobin levels of the mice fed S. chinensis Baill extract were significantly lower than those of the control group (p<0.05). Therefore, we conclude that S. chinensis Baill is effective in controlling hyperglycemia in animal models of diabetes mellitus.

Batch Variation and Pharmacokinetics of Oral Sustained Release Melatonin-loaded Sugar Spheres in Human Subjects

  • Lee, Beom-Jin;Ryu, Seung-Goo;Choi, Han-Gon;Kim, Chong-Kook;Parrott, Keith-A.;Ayres, James-W.;Sack, Robert-L.
    • Archives of Pharmacal Research
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    • v.20 no.6
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    • pp.555-559
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    • 1997
  • The three different batches of an oral sustained release melatonin (MT) delivery system were prepared by aqueous-based fluid-bed coating of the sugar spheres for the evaluation of in vitro release characteristics and plasma concentration profiles in human subjects. The MT contents in 20% coated sugar spheres of three batches (B1, B2 and B3) were $3.3{\pm}0.08$, $2.4{\pm}0.1$ and $2.5{\pm}0.13$ mg per gram of coated sugar spheres, respectively. The release profiles of three different batches had a very similar fashion. However, the release profiles of three different batches had a very similar fashion. However, the release half-lives $(T_{50%})$ of MT from B1, B2 and B3 was $3.70{\pm}0.2$, $5.2{\pm}0.2$ and $4.9{\pm}0.07h$, respectively. Plasma concentration profiles of sustained release 0.2mg melatonin-loaded sugar spheres containing 10% immediate release melatonin in gelatin capsules (B1 and B2) were then evaluated in human subjects. The in vivo plasma concentration profies of the two batches (B1 and B2) were very similar each other and located between the physiological endogenous ranges. The time to reach the peak concentration $(T_max)$ was more advanced in case of B1 when compared to B2. However, there was no statistically significant difference in the maximum concentration $(C_max)$ and the area under the curve (AUC) between B1 and B2. The AUC of melatonin-loaded sugar spheres containing 10% and 20% immediate release MT in human subjects had a good linearity between dose and AUC, regardless of the fraction of immediate release MT, indicating the first order elimination process of MT within these doses. The current oral sustained release MT delivery system may be utilized to treat circadian rhythm disorders if it is proven to be more clinically useful when compared to immediate release MT.

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Physiochemical characteristics and fermentation ability of milk from Czech Fleckvieh cows are related to genetic polymorphisms of β-casein, κ-casein, and β-lactoglobulin

  • Kyselova, Jitka;Jecminkova, Katerina;Matejickova, Jitka;Hanus, Oto;Kott, Tomas;Stipkova, Miloslava;Krejcova, Michaela
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.1
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    • pp.14-22
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    • 2019
  • Objective: The aim of the study was to find a possible association between the ${\beta}-$ and ${\kappa}-casein$ and ${\beta}-lactoglobulin$ genotypes and important milk physiochemical and technological characteristics such as acidity, alcohol stability, the contents of some minerals and the parameters of acid fermentation ability (FEA) in Czech Fleckvieh Cattle. Methods: Milk and blood samples were collected from 338 primiparous Czech Fleckvieh cows at the same stage of lactation. The genotypes of individual cows for ${\kappa}-casein$ (alleles A, B, and E) and ${\beta}-lactoglobulin$ (alleles A and B) were ascertained by polymerase chain reaction-restriction fragment length polymorphism, while their ${\beta}-casein$ (alleles $A^1$, $A^2$, $A^3$, and B) genotype was determined using melting curve genotyping analysis. The data collected were i) milk traits including active acidity (pH), titratable acidity (TA), alcohol stability (AS); calcium (Ca), phosphorus (P), sodium (Na), magnesium (Mg), and potassium (K) contents; and ii) yoghurt traits including active acidity (Y-pH), titratable acidity (Y-TA), and the counts of both Lactobacilli and Streptococci in 1 mL of yoghurt. A linear model was assumed with fixed effects of herd, year, and season of calving, an effect of the age of the cow at first calving and effects of the casein and lactoglobulin genotypes of ${\beta}-CN$ (${\beta}-casein$, CSN2), ${\kappa}-CN$ (${\kappa}-casein$, CSN3), and ${\beta}-LG$ (${\beta}-lactoglobulin$, LGB), or the three-way interaction between those genes. Results: The genetic polymorphisms were related to the milk TA, AS, content of P and Ca, Y-pH and Lactobacilli number in the fresh yoghurt. The CSN3 genotype was significantly associated with milk AS (p<0.05). The effect of the composite CSN2-CSN3-LGB genotype on the investigated traits mostly reflected the effects of the individual genes. It significantly influenced TA (p<0.01), Y-pH (p<0.05) and the log of the Lactobacilli count (p<0.05). Conclusion: Our findings indicate that the yoghurt fermentation test together with milk proteins genotyping could contribute to milk quality control and highlight new perspectives in dairy cattle selection.

Efficiency in the Password-based Authenticated Key Exchange (패스워드 기반 인증 키 공유 프로토콜에서의 효율성)

  • 황정연;홍석희;박혜영;장상운;박영호;류희수
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.12 no.6
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    • pp.113-124
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    • 2002
  • Proposals for a password-based authenticated key exchange protocol that have been published so far almost concentrated on the provable security. But in a real environment such as mobile one, efficiency is a critical issue as security. In this paper we discuss the efficiency of PAK which is secure in the random oracle model [l]. Among 4 hash functions in PAK the instantiation for $H_1$, which outputs a verifier of the password, has most important effect on the computational efficiency. We analyze two different methods for $H_1$ suggested in [1] and we show that $H_{lq}$ has merits in transforming to EC or XTR variants as well as in the efficiency. As an efficient variant. we propose PAK2-EC and PAK2-XTR which do not require any additional step converting a hash output into a point of elliptic curve or XTR subgroup when compared to the previous work on the PAK[2]. Finally we compare PAK2 with the password-based authenticated key exchange protocols such as SPEKE, SRP, and AMP.

A Study of Dyeing Properties of Cotton Fabrics Under Supercritical CO2 Depending on Dyestuff : by C.I. Disperse orange 155, C.I. Disperse red 167 (초임계 유체 염색용 염료에 따른 면 섬유의 염색 특성 : C.I. Disperse orange 155, C.I. Disperse red 167)

  • Choi, Hyunseuk;Kim, Hunmin;Jeon, Taeyoung
    • Textile Coloration and Finishing
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    • v.34 no.2
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    • pp.93-101
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    • 2022
  • In this study, the dyeing properties of supercritical fluid dyed cotton fabrics were investigated which use two types of dyes, such as C.I. Disperse orange and C.I. Disperse red 167. Dyeing temperature, pressure and leveling time were equally applied at 130 ℃, 250 bar, and 60 minutes with reference to the related literature, and experiments were performed at concentrations of 0.04, 0.1, 0.4 and 0.8 % o.w.f with different concentrations. Dyeability was confirmed through measurement of washing fastness and color coordinate, and a calibration curve of each dye was drawn up and the absorbance of the residual dye was measured to confirm the amount of residual dye and the dye exhaustion rate at the corresponding concentration. As a result of color difference measurement, as the concentration increased, the L* value decreased and the K/S value increased. However, as the concentration increased, the increase in K/S value decreased compared to the input amount, and this tendency was more obvious in C.I. Disperse red 167 than in C.I. Disperse orange 155. The dye exhaustion rate which was calculated by using the amount of residual dye in the pot was also C.I. Disperse orange 155 was 96.16 % and C.I. Disperse red 167 was 94.57 %. However, as the dyeing concentration increased, the dye exhaustion rate decreased, that C.I. Disperse orange was 95.33 % and C.I. Disperse red 167 was 90.63 %. As a result of the washing fastness test for both dyes, dyed samples of which concentrations were 0.4 and 0.8 % o.w.f decreased by 0.5 ~ 1.0 grade. This is predicted because the dye did not completely adhere to the amorphous region of the cotton fiber and the dye simply adsorbed. The fastness to rubbing also maintained at least grade 3-4 up to the 0.1 % o.w.f concentration, but at the concentration of 0.4 % o.w.f or higher, it fell to grade 1 or lower, showing a very poor friction fastness.

Full-Endoscopic versus Minimally Invasive Lumbar Interbody Fusion for Lumbar Degenerative Diseases : A Systematic Review and Meta-Analysis

  • Son, Seong;Yoo, Byung Rhae;Lee, Sang Gu;Kim, Woo Kyung;Jung, Jong Myung
    • Journal of Korean Neurosurgical Society
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    • v.65 no.4
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    • pp.539-548
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    • 2022
  • Objective : Although full-endoscopic lumbar interbody fusion (Endo-LIF) has been tried as the latest alternative technique to minimally invasive transforaminal lumbar interobody fusion (MIS-TLIF) since mid-2010, the evidence is still lacking. We compared the clinical outcome and safety of Endo-LIF to MIS-TLIF for lumbar degenerative disease. Methods : We systematically searched electronic databases, including PubMed, EMBASE, and Cochrane Library to find literature comparing Endo-LIF to MIS-TLIF. The results retrieved were last updated on December 11, 2020. The perioperative outcome included the operation time, blood loss, complication, and hospital stay. The clinical outcomes included Visual analog scale (VAS) of low back pain and leg pain and Oswestry disability index (ODI), and the radiological outcome included pseudoarthosis rate with 12-month minimum follow-up. Results : Four retrospective observational studies and one prospective observational study comprising 423 patients (183 Endo-LIF and 241 MIS-TLIF) were included, and the pooled data analysis revealed low heterogeneity between studies in our review. Baseline characteristics including age and sex were not different between the two groups. Operation time was significantly longer in Endo-LIF (mean difference [MD], 23.220 minutes; 95% confidence interval [CI], 10.669-35.771; p=0.001). However, Endo-LIF resulted in less perioperative blood loss (MD, -144.710 mL; 95% CI, 247.941-41.478; p=0.023). Although VAS back pain at final (MD, -0.120; p=0.586), leg pain within 2 weeks (MD, 0.005; p=0.293), VAS leg pain at final (MD, 0.099; p=0.099), ODI at final (MD, 0.141; p=0.093) were not different, VAS back pain within 2 weeks was more favorable in the Endo-LIF (MD, -1.538; 95% CI, -2.044 to -1.032; p<0.001). On the other hand, no statistically significant group difference in complication rate (relative risk [RR], 0.709; p=0.774), hospital stay (MD, -2.399; p=0.151), and pseudoarthrosis rate (RR, 1.284; p=0.736) were found. Conclusion : Relative to MIS-TLIF, immediate outcomes were favorable in Endo-LIF in terms of blood loss and immediate VAS back pain, although complication rate, mid-term clinical outcomes, and fusion rate were not different. However, the challenges for Endo-LIF include longer operation time which means a difficult learning curve and limited surgical indication which means patient selection bias. Larger-scale, well-designed study with long-term follow-up and randomized controlled trials are needed to confirm and update the results of this systematic review.

Simultaneous Estimation of the Fat Fraction and R2* Via T2*-Corrected 6-Echo Dixon Volumetric Interpolated Breath-hold Examination Imaging for Osteopenia and Osteoporosis Detection: Correlations with Sex, Age, and Menopause

  • Donghyun Kim;Sung Kwan Kim;Sun Joo Lee;Hye Jung Choo;Jung Won Park;Kun Yung Kim
    • Korean Journal of Radiology
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    • v.20 no.6
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    • pp.916-930
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    • 2019
  • Objective: To investigate the relationships of T2*-corrected 6-echo Dixon volumetric interpolated breath-hold examination (VIBE) imaging-based fat fraction (FF) and R2* values with bone mineral density (BMD); determine their associations with sex, age, and menopause; and evaluate the diagnostic performance of the FF and R2* for predicting osteopenia and osteoporosis. Materials and Methods: This study included 153 subjects who had undergone magnetic resonance (MR) imaging, including MR spectroscopy (MRS) and T2*-corrected 6-echo Dixon VIBE imaging. The FF and R2* were measured at the L4 vertebra. The male and female groups were divided into two subgroups according to age or menopause. Lin's concordance and Pearson's correlation coefficients, Bland-Altman 95% limits of agreement, and the area under the curve (AUC) were calculated. Results: The correlation between the spectroscopic and 6-echo Dixon VIBE imaging-based FF values was statistically significant for both readers (pc = 0.940 [reader 1], 0.908 [reader 2]; both p < 0.001). A small measurement bias was observed for the MRS-based FF for both readers (mean difference = -0.3% [reader 1], 0.1% [reader 2]). We found a moderate negative correlation between BMD and the FF (r = -0.411 [reader 1], -0.436 [reader 2]; both p <0.001) with younger men and premenopausal women showing higher correlations. R2* and BMD were more significantly correlated in women than in men, and the highest correlation was observed in postmenopausal women (r = 0.626 [reader 1], 0.644 [reader 2]; both p < 0.001). For predicting osteopenia and osteoporosis, the FF had a higher AUC in men and R2* had a higher AUC in women. The AUC for predicting osteoporosis was highest with a combination of the FF and R2* in postmenopausal women (AUC = 0.872 [reader 1], 0.867 [reader 2]; both p < 0.001). Conclusion: The FF and R2* measured using T2*-corrected 6-echo Dixon VIBE imaging can serve as predictors of osteopenia and osteoporosis. R2* might be useful for predicting osteoporosis, especially in postmenopausal women.

Influence of Microcrack on Brazilian Tensile Strength of Jurassic Granite in Hapcheon (미세균열이 합천지역 쥬라기 화강암의 압열인장강도에 미치는 영향)

  • Park, Deok-Won;Kim, Kyeong-Su
    • Korean Journal of Mineralogy and Petrology
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    • v.34 no.1
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    • pp.41-56
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    • 2021
  • The characteristics of the six rock cleavages(R1~H2) in Jurassic Hapcheon granite were analyzed using the distribution of ① microcrack lengths(N=230), ② microcrack spacings(N=150) and ③ Brazilian tensile strengths(N=30). The 18 cumulative graphs for these three factors measured in the directions parallel to the six rock cleavages were mutually contrasted. The main results of the analysis are summarized as follows. First, the frequency ratio(%) of Brazilian tensile strength values(kg/㎠) divided into nine class intervals increases in the order of 60~70(3.3) < 140~150(6.7) < 100~110·110~120(10.0) < 90~100(13.3) < 80~90(16.7) < 120~130·130~140(20.0). The distribution curve of strength according to the frequency of each class interval shows a bimodal distribution. Second, the graphs for the length, spacing and tensile strength were arranged in the order of H2 < H1 < G2 < G1 < R2 < R1. Exponent difference(λS-λL, Δλ) between the two graphs for the spacing and length increases in the order of H2(-1.59) < H1(-0.02) < G2(0.25) < G1(0.63) < R2(1.59) < R1(1.96)(2 < 1). From the related chart, the six graphs for the tensile strength move gradually to the left direction with the increase of the above exponent difference. The negative slope(a) of the graphs for the tensile strength, suggesting a degree of uniformity of the texture, increases in the order of H((H1+H2)/2, 0.116) < G((G1+G2)/2, 0.125) < R((R1+R2)/2, 0.191). Third, the order of arrangement between the two graphs for the two directions that make up each rock cleavage(R1·R2(R), G1·G2(G), H1·H2(H)) were compared. The order of arrangement of the two graphs for the length and spacing is reverse order with each other. The two graphs for the spacing and tensile strength is mutually consistent in the order of arrangement. The exponent differences(ΔλL and ΔλS) for the length and spacing increase in the order of rift(R, -0.08) < grain(G, 0.14) < hardway(H, 0.75) and hardway(H, 0.16) < grain(G, 0.23) < rift(R, 0.45), respectively. Fourth, the general chart for the six graphs showing the distribution characteristics of the microcrack lengths, microcrack spacings and Brazilian tensile strengths were made. According to the range of length, the six graphs show orders of G2 < H2 < H1 < R2 < G1 < R1(< 7 mm) and G2 < H1 < H2 < R2 < G1 < R1(≦2.38 mm). The six graphs for the spacing intersect each other by forming a bottleneck near the point corresponding to the cumulative frequency of 12 and the spacing of 0.53 mm. Fifth, the six values of each parameter representing the six rock cleavages were arranged in the order of increasing and decreasing. Among the 8 parameters related to the length, the total length(Lt) and the graph(≦2.38 mm) are mutually congruent in order of arrangement. Among the 7 parameters related to the spacing, the frequency of spacing(N), the mean spacing(Sm) and the graph (≦5 mm) are mutually consistent in order of arrangement. In terms of order of arrangement, the values of the above three parameters for the spacing are consistent with the maximum tensile strengths belonging to group E. As shown in Table 8, the order of arrangement of these parameter values is useful for prior recognition of the six rock cleavages and the three quarrying planes.