• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.843-855
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• 2020

X-plane submarines show better maneuverability as they have much longer span of control plane than that of cross plane submarines. In this study, captive model tests were conducted to evaluate the maneuverability of an X-plane submarine using Computational Fluid Dynamics (CFD) and a mathematical maneuvering model. For CFD analysis, SNUFOAM, CFD software specialized in naval hydrodynamics based on the open-source toolkit, OpenFOAM, was applied. A generic submarine Joubert BB2 was selected as a test model, which was modified by Maritime Research Institute Netherlands (MARIN). Captive model tests including propeller open water, resistance, self-propulsion, static drift, horizontal planar motion mechanism and vertical planar motion mechanism tests were carried out to obtain maneuvering coefficients of the submarine. Maneuvering simulations for turning circle tests were performed using the maneuvering coefficients obtained from the captive model tests. The simulated trajectory showed good agreement with that of free running model tests. From the results, it was proved that CFD simulations can be applicable to obtain reliable maneuvering coefficients for X-plane submarines.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.175-187
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• 1998

The purpose of this study was to predict the prognosis of class III malocclusion treatments. 25 patients selected for this study were devided into two groups by the stability of dentitional, skeletal and soft tissue profile improvement. One was stable group which consisted of 12 children and the other was relapse group with 13 children. Various measurements in initial lateral cephalogram were calculated and analyzed by t-test, correlation coefficient and discriminant analysis. The results of this study were summarized as follows 1. In both stable and relapse groups, there was not distinct difference in the antero-posterior skeletal relationship (P<0.05). 2. As the result of wits, hn to occlusal plane angle and occlusal plane to mandubular plane angle, the occlusal plane of relapse group was stepper than that of the stable group. 3. In correlation coefficient analysis, the overjet and the occlusal plane to mandibular plane angle showed significant correlations (p<0.001, p<0.01). 4. The discriminant function was obtained from three major influential measurements; overjet, AB to occlusal plane angle and articular angle, and this function could discriminate correctly in 88% of these samples.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.2
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• pp.56-61
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• 2015

The effects of the growth temperature on the properties of a-plane GaN epi-layer on r-plane sapphire by HVPE were studied, when the constant V/III ratio and the flow rate of HCl for the Ga source channel was fixed at 10 and 700 sccm, respectively. Additionally the effects of V/III ratios for source gasses were studied when growth temperature and the flow rate of HCl for the Ga source channel was fixed at $1000^{\circ}C$ and 700 sccm, respectively. As the growth temperature was increased, the values of Full Width Half Maximum (FWHM) for Rocking curve (RC) of a-plane GaN (11-20) epi-layer were decreased and thickness of a-plane GaN epi-layer were increased. As V/III ratios were increased at $1000^{\circ}C$, the values of FWHM for RC of a-plane GaN (11-20) were declined and thickness of a-plane GaN epi-layer were increased. The a-plane GaN (11-20) epi-layer grown at $1000^{\circ}C$ and V/III ratio = 10 showed the lowest value FWHM for RC of a-plane GaN (11-20) for 734 arcsec and the smallest dependence of Azimuth angle for FWHM of (11-20) RCs.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.14 no.2
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• pp.1-15
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• 2008

Purpose : This survey was to investigate on the effect of each region changed in trunk through sagittal plane after Trunk Flexion-Extension Exercise. Methods : 18 students of Gimcheon College participated in this study for the period of July 9-30, 2007. Analyzed factor were 1) degree of pain 2) presence of Gillet test and 3) difference of right-left for 7 landmark region in trunk applying I.B.S.-2000 after Trunk Flexion - Extension Exercise. We used the SPSS $PC^+$ program for classifying into analysis of frequency, $x^2$-test, t-test and Simple Linear Regression analysis test. Results: Followings are concluded For degree of pain, 13(72.2%) of students answered "No pain" after Trunk Flexion-Extension Exercise and in the result 4 more students decreased the pain. In the Gillet test, 14(77.8%) of students answered "positive" after Trunk Flexion-Extension Exercise and in the result 4 more students increased mobility of Sacroiliac joint. In the differences of right-left for 7 landmark region in trunk by B.M.I. scale, Slim type was decreased both Acromion(0.45mm), both Iliac crest(0.44mm), and both ASIS(0.31mm) to anterior plane, Normal type was decreased both inferior angle of Scapular(0.02mm), both L4-5(0.07mm), and both PSIS(0.09mm) to posterior plane Fatness type was decrease both Acromion(0.05mm), both ASIS(0.05mm) to anterior plane. In the differences of right-left for 7 landmark region in trunk for degree of pain No pain group was decreased both Acromion(0.17mm), both Nipple(0.25mm) to anterior plane and both PSIS(0.13mm) to posterior plane Pain group was decreased both Acromion(0.04mm), both Iliac creast(0.03mm) to anterior plane and both inferior angle of Scapular(0.18mm) both PSIS(0.13mm) to posterior plane. In the difference of right-left for 7 landmark region in trunk for each of the exercises, Both iliac crest(0.1mm), both ASIS(0.12mm) to anterior plane were decreased after Flexion Trunk Exercise. Both acromion(0.27mm) to anterior plane, both inferior angle of scapular(0.14mm) and both PSIS(0.12mm) to posterior plane were decreased after Extension Trunk Exercise. Each of the exercises, The both inferior angle of Scapular showed high scores($0.65{\pm}0.23$) at Trunk Extension Exercise group and there was statistical significance between Trunk Flexion Exercise group and Extension exercise group(t :-2.502, p < 0.05). 7. At Pre-exercise group, Both inferior angle of Scapular showed low scores($0.23{\pm}8.27$) at Trunk Extension Exercise group and there was statistical significance between Pre- Exercise group and Trunk Extension Exercise group(t :-2.5430, p<0.05). Conclusion : The simple linear regression analysis was presented at Acromion(-0.243), L4-5(-0.753), PSIS(0.576) and there was statistical significance in BMI scale(p<0.01).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.8
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• pp.1-6
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• 2010

We report on the electrical properties of Ti/Al/Ni/Au (20 nm/ 150 nm/ 30 nm/ 100 nm) Ohmic contacts and the anisotropic conductivity of n-type ${\alpha}$-plane ([11-20]) GaN grown on $\gamma$-plane ([1-102]) sapphire substrates. The Ti/Al/Ni/Au Ohmic contacts and their sheet resistances are characterized by using the transfer length method (TLM) as a function of azimuthal angles. It is found that the specific contact resistance does not depend on the axis orientation and there are significant electrical anisotropy in ${\alpha}$-plane GaN films on $\gamma$-plane sapphire substrates, and the sheet resistance varies with azimuthal angles. The sheet resistance values in the direction parallel to m-axis [1-100] are 25% ~ 75% lower than those parallel to c-axis [0001] directions. Thus, Basal stacking faults (BSFs) are offered as a feasible source of the anisotropic mobility in defected m-axis direction because the band-edge discontinuities owing to the differential band gap structure.

• The korean journal of orthodontics
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• v.39 no.3
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• pp.136-145
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• 2009

Objective: CBCT has become popular for orthodontic diagnosis and treatment planning in recent times. The 3D pharyngeal airway space needs to be analysed using a 3D diagnostic tool. The aim of this study was to analyse the pharyngeal airway of different craniofacial morphology using CBCT. Methods: The sample compromised 102 subjects divided into 3 groups (Class I, II, III) and 6 subgroups according to normal or vertical craniofacial patterns. All samples had CBCT (VCT, Vatech, Seoul, Korea) taken for orthodontic treatment. The pharyngeal airway was assessed according to the reference planes: aa plane (the most anterior point on the anterior arch of atlas), $CV_2$ plane, and $CV_3$ plane (most infero-anterior point on the body of the second & third cervical vertebra). The intergroup comparison was performed with one-way ANOVA and duncan test as a second step. Results: The results showed the pharyngeal airway and anteroposterior width of group 2 (Class II) in aa plane, $CV_2$ plane, $CV_3$ plane were significant narrower than in group 3 (Class III). There was no significant difference between vertical and normal craniofacial patterns except for the anteroposterior pharyngeal width of Group 1 (Class I) in aa plane. Conclusions: Subjects with Class II patterns have a significantly narrower pharyngeal airway than those with Class III. However there was no difference in pharyngeal airway between vertical and normal craniofacial morphology.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.835-842
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• 2022

This study is aimed to evaluate the effects of a synthetic MR technique in reducing metal artifacts. In the experiment, the in-plane and through-plane images were acquired by applying a synthetic MR technique and a high-speed spin echo technique to a phantom manufactured with screw for spinal surgery. The area of the metal artifact was compared. The metal artifacts were measured by dividing the signal-loss and the signal pile-up areas, and the area of the final artifact was calculated through the sum of the two. As a result, the metal artifacts were relatively reduced when the synthetic MR techniques were applied to both in-plane and through-plane. Comparing by sequence, the in-plane T1 images decreased by 23.45%, T2 images by 20.85%, PD images by 19.67%, and FLAIR images by 22.12%. Also, in the case of the through-plane, the T1 image decreased by 62.95%, the T2 image decreased by 73.93%, the PD image decreased by 74.68%, and the FLAIR image decreased by 66.43%. The cause of this result is that when the synthetic MR technique is applied, the distortion is due to the signal pile-up and does not occur and the size of the entire metal artifact is reduced. Therefore, synthetic MR technique can very effectively reduce metal artifacts, which can help to increase the diagnostic value of images.

• The Pure and Applied Mathematics
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• v.19 no.4
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• pp.337-347
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• 2012

The taxicab distance and Chinese-checker distance in the plane are practical distance notions with a wide range of applications compared to the Euclidean distance. The ${\alpha}$-distance was introduced as a generalization of these two distance functions. In this paper, we study alpha circle, trigonometry, and the area of a triangle in the plane with ${\alpha}$-distance.

• Electronics and Telecommunications Trends
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• v.30 no.2
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• pp.87-94
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• 2015

인터넷 트래픽의 향후 5년간 연평균성장률(CAGR)은 24%(유선 트래픽이 21%, 모바일 트래픽이 68%)로 예상되지만, 인터넷 트래픽을 처리하는 칩셋의 성능 연평균성장률은 14% 정도로 예상되고 있다. 이에 따라, 증가하는 인터넷 트래픽과 이를 처리하는 칩셋의 성능 사이에 격차(Forwarding Gap)가 발생하고 있는 상황이다. 이런 격차를 줄이기 위해 시작된 연구기술이 데이터 플레인 가속화(DPA: Data Plane Acceleration) 기술이다. 본고에서는 데이터 플레인 가속화 기술로 최근 공개 소프트웨어로 발표된 인텔의 DPDK(Data Plane Development Kit)기술과 Linaro의 ODP(Open Data Plane)기술을 중심으로 고속 네트워크 패킷처리를 위한 데이터 플레인 가속화 기술동향을 소개한다.

• The Journal of the Acoustical Society of Korea
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• v.21 no.4E
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• pp.183-188
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• 2002

In this paper, the strong in-plane vibration has been experimentally observed at the end of a finite cylindrical shell. The strong in-plane vibration was generated by the evanescent wave field, which was excited along about half the length of the shell. The evanescent waves were generated due to mode conversion of elastic waves at the ends of the cylindrical shells. The results show that the strong in-plane end vibration can be generated in cylindrical shells.