• Communications of the Korean Mathematical Society
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• v.38 no.2
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• pp.331-340
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• 2023

In this paper, the concept of a maximal chain of ideals is introduced. Some properties of such chains are studied. We introduce some other concepts related to a maximal chain of ideals such as the n-maximal ideal, the maximal dimension of a ring S (M. dim(S)), the maximal depth of an ideal K of S (M.d(K)) and maximal height of an ideal K(M.d(K)).

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.499-508
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• 2004

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, autogenous bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of autogenous bone and xenogenic bone $(BBP^{(R)})$ grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, autogenous bone with PRP was inserted for 25 infrabony pockets as first test group, and $(BBP^{(R)})$ with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. There were significant differences between average probing pocket depth and clinical attachment level of 3, 6 months and minimal and maximal attachment level after 6 months each other. 2. There were significant differences in average probing pocket depth of control group and 2nd experimental group between 1 and 6 months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6 month of surgery. 3. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minimal and maximal probing attachment level. As the result, PRP with bone graft could be very effective for regeneration of periodontium and there was no difference between xenogenic bone and autogenous bone.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.737-747
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• 2001

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, synthetic bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of synthetic bone ($Biogran^{(R)}$) and xenogenic bone ($BBP^{(R)}$) grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, $Biogran^{(R)}$ with PRP was inserted for 25 infrabony pockets as first test group, and $BBP^{(R)}$ with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. 6 months after surgery, each difference of average probing pocket depth was $2.61{\pm}0.23$ for control, $3.40{\pm}0.30$ for 1st test, and $3.45{\pm}0.37$ for 2nd test group. 2. 6 months after surgery, each difference of clinical probing attachment level was $1.39{\pm}0.12$ for control, $2.88{\pm}0,24$ for 1st, and $2.86{\pm}0,27$ for 2nd test group. 3. 6 months after surgery, each difference of Maximal probing attachment level was $1.11{\pm}0.16$ for control, $3.28{\pm}0.30$ for 1st, and $3.27{\pm}0.35$ for 2nd test group. 4. There were significant differences for clinical change of each three group which were between average probing pocket depth and clinical attachment level of 3,6 months and minimal and maximal attachment level after 6 months 5. There were significant differences for average probing pocket depth which were only at control group and 2nd test group between 1 and 6months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6month of surgery. 6. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minima1 and maximal probing attachment level. As the result, PRP with bone graft is very effective for regeneration of periodontium and there is no difference between xenogenic bone and synthetic bone.

• ETRI Journal
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• v.21 no.3
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• pp.41-48
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• 1999

We have calculated differential reflection coefficient for isolated well structure of micro-scale, etched on dielectric surface. The differential reflection coefficient is computed using Green's second integral theorem. The purpose of our computation is to find a class of well profiles which give maximal diffusive scattering. To have such a maximal effect, we have concluded that the waist radius of Gaussian beam and its wavelength should be comparable to the well width and that well depth has to be larger than a wavelength. Exact calculation of differential reflection coefficients of dielectric surface with isolated structure on it may be used for the examination of dielectric surfaces and also in making simple but efficient diffuser.

• The Korean Journal of Pain
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• v.35 no.3
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• pp.345-352
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• 2022

Background: Optimal needle depth in transforaminal epidural injection (TFEI) is determined by body measurements and is influenced by the needle entry angle. Physician can choose the appropriate needle length and perform the procedure more effectively if depth is predicted in advance. Methods: This retrospective study included patients with lumbosacral pain from a single university hospital. The skin depth from the target point was measured using magnetic resonance imaging transverse images. The depth was measured bilaterally for L4 and L5 TFEIs at 15°, 20°, and 25° oblique angles from the spinous process. Results: A total of 4,632 measurements of 386 patients were included. The lengths of the left and right TFEI at the same level and oblique angle were assessed, and no statistical differences were identified. Therefore, linear regression analysis was performed for bilateral L4 and L5 TFEIs. The R-squared values of height and weight combined were higher than the height, weight, and body mass index (BMI). The following equation was established: Depth (mm) = a - b (height, cm) + c (weight, kg). Based on the equation, maximal BMI capable with a 23G, 3.5-inch, Quincke-type point spinal needle was presented for three different angles (15°, 20°, and 25°) at lumbar levels L4 and L5. Conclusions: The maximal BMI that derived from the formulated equation is listed on the table, which can help in preparations for morbid obesity. If a patient has bigger BMI than the one in the table, the clinician should prepare longer needle than the usual spinal needle.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.185-195
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• 1991

This study was undertaken to grope the correlation of the maximal bite force and tooth-craniofacial structure. The maximal bite force of 76 adult male, aged 18-28 (mean aged: $23.4{\pm}2.2$) years, was estimated and cephalometric headplates were measured, tabulated and statistically analyzed. The results were as follows. 1. 59.61kg of bite force in first molar, 45.38kg in premolar and 17.10kg in central incisor were arranged. 2. The bite force was negatively correlated to genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and positively correlated to posterior height of face, length of mandibular body, length of ramus, facial depth in craniofacial structure. 3. The group with strong bite force showed small genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and long posterior height of face, length of mandibular body, length of ramus, facial depth. So they manifested the tendency to brachycephalic pattern, on the other hand, the group with weak bite force manifested the tendency to dolichocephalic pattern. 4. There is no correlationships between bite force and mesial inclination of premolar axis in this subject. 5. It is considered bite force have an effect upon craniofacial pattern, especially upon the lower face.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.173-181
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• 2011

Purpose: Masseter muscle is an important muscle of mastication. Because it has a great influence on the shape of low facial contour, patients who have masseteric hypertrophy show square-shaped jaw appearance. As aesthetic procedures for the reduction of the masseter muscle volume, radiofrequency ablation or botulinum toxin injection is at the center of attention. Authors studied the anatomical measurement of the thickness and width of masseter muscle and the surface mapping of the maximal thickness point using computed tomography (CT) scan to identify the useful guide for the injection of botulinum toxin in masseteric hypertrophy patients. Methods: We analyzed 2 mm-thickness OMU (ostiomeatal unit) CT of 112 normal people (224 masseter muscles) taken from June 2009 to May 2010. First, we measured the thickness, width and depth of the masseter muscle from the skin surface and analysed each by side, sex and age, respectively. The distribution of the thickness of the muscle and the correlation of thickness and width of the muscle were studied also. Second, we underwent surface mapping of the maximal thickness point using CT analysis by means of checking the vertical and horizontal distance from the angle of the mandible. Results: The average thickness and width of the masseter muscle was 17.73 mm and 40.78 mm in the male patients and were 14.33 mm and 37.42 mm in the female patients. Statistically, both figures of the male patients were larger than those of the female patients. However, the depth of the muscle from the skin surface in female patients (7.37 mm) was larger than that of the male patients (6.15 mm). There were no statistical difference in side or age. The width and thickness of the masseter muscle were in the positive correlation. The location of maximal thickness point of the masseter muscle was 27.77 mm vertically and 27.68 mm horizontally in the male patients, and 25.19 mm vertically and 25.42 mm horizontally in the female patients from the angle of mandible. Conclusion: We were able to present statistical evidence of the diagnosis and treatment of the masseteric hypertrophy regarding the anatomical measurements such as the thickness and width. And the maximal thickness point of the masseter muscle may be a useful guide for the clinical procedures of botulinum toxin injection.

• Bulletin of the Korean Mathematical Society
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• v.51 no.2
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• pp.373-386
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• 2014

Let (R,m) be a commutative Noetherian local ring. In this paper we show that a finitely generated R-module M of dimension d is Cohen-Macaulay if and only if there exists a proper ideal I of R such that depth($M/I^nM$) = d for $n{\gg}0$. Also we show that, if dim(R) = d and $I_1{\subset}\;{\cdots}\;{\subset}I_n$ is a chain of ideals of R such that $R/I_k$ is maximal Cohen-Macaulay for all k, then $n{\leq}{\ell}_R(R/(a_1,{\ldots},a_d)R)$ for every system of parameters $a1,{\ldots},a_d$ of R. Also, in the case where dim(R) = 2, we prove that the ideal transform $D_m(R/p)$ is minimax balanced big Cohen-Macaulay, for every $p{\in}Assh_R$(R), and we give some equivalent conditions for this ideal transform being maximal Cohen-Macaulay.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.571-576
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• 2023

In this study, the harmless crack size(a_hml) according to the residual stress depth was evaluated using the fatigue limit of SCM440 steel by quenching-tempering(QT) and induction hardening(IH), and threshold stress intensity factor of QT steel. Because the residual stress increased rapidly as the crack depth increased, a_hml was determined at the depth of all the crack aspect ratio(As) regardless of Type I-III, and a_hml also increased according to the residual stress depth. a_hml was minimal at As=1.0 and maximal at As=0.1, but was almost similar on each Type. a_hml was small the dependence on As.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.57-66
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• 2009

Zigbee is a universal communication standard used in USN and is utilized in various applications. Zigbee protocol provides an address within a single PAN network, and at this time, it uses DAA. This is a method that divides a 16-bit address area into blocks with a fixed size according to the depth to assign one to each node. However, this method is limited because it has to assign addresses in 16 bits. As the depth increases, the number of nodes also increases exponentially to the maximal number of routers provided to each depth. Therefore, it is difficult to construct a huge network with numerous routers and large depth as in the places which are wide or have many shadow areas. Besides, since all the operations are performed in a single PAN network, it is hard to make several PANs into a single network. This article suggests new addressing and routing methods that can construct several PAN networks into a single network and combine broad area with less limitation in the number of routers and depth by extending the Zigbee-based network. Moreover, this paper has tested its performance and has verified its usability through substantive tests.