• Title/Summary/Keyword: $L^2$-distance

Search Result 840, Processing Time 0.033 seconds

A study on the northern sea route safety convoy using ship handling simulation (선박조종시뮬레이션을 이용한 북극해 안전 호송에 관한 연구)

  • Kim, Won-Ouk;Kim, Jong-Su
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.40 no.9
    • /
    • pp.847-851
    • /
    • 2016
  • Due to global warming it is estimated that the arctic ocean route will be avaliable and traffic will increase by approximately year 2030. However, most navigation in the arctic is based on the ice breaker captains'orders, there is no exact measurement of convoy speed and distance between ships. So, this research was conducted to find out the minimum safe separation distance and minimum breaking distance via ship controling simulations, and the results are as stated. For breaking distances, for ships that have a lead distance which is 2~4 times the width of the ship and traveling less than 7 knots, crash astern and crash astern & hard rudder showed no significant difference. But ships traveling at 10 knots there was a decrease in breaking distance of 1L, from 3.5L to 2.5L. By analyzing 10 subject ships by crash astern the breaking distance for 5 knots is 0.98L~1.8L, for 8 knots is 1.9L~4.0L. The minimum safe separation distance in narrow sea-ways is 6L, but as the arctic sea-way is only one-way 3L is required. As the result, it is found that in the arctic the safe escort speed is less than 5 knots, if the escort speed is 8knots or more and by using crash astern & hard rudder to break the safe distance should be kept at 3.4L.

Nerve length measurement method in a radial motor nerve conduction study

  • Kim, Jae-Gyum;Kim, Yoohwan;Seok, Hung Youl;Kim, Byung-Jo
    • Annals of Clinical Neurophysiology
    • /
    • v.19 no.1
    • /
    • pp.28-33
    • /
    • 2017
  • Background: Previous studies of radial nerve conduction study (NCS) did not present how to measure the length of the radial nerve across the elbow, and did not even mention how to manage the spiral course of the nerve. This study aimed to applicate the most reliable method to measure the length of the radial nerve during NCS. Methods: Three points (A, B, and C) were determined along the relatively straight course of the radial nerve. The distance was measured using three different methods: L1) straight distance corresponding to the A-C distance, L2) sum of the distances corresponding to the A-B-C distance, L3) based on the L2, but the elbow is flexed at a $45^{\circ}$ angle. We compared the three methods of distance measurement and the calculated nerve conduction velocities (V1, V2, and V3) in normal healthy subjects. Results: 19 normal participants were enrolled. The mean value for method L1, L2 and L3 were $22.5{\pm}1.8cm$, $24.0{\pm}2.1cm$, and $23.2{\pm}2.1cm$ (p < 0.001). Calculated conduction velocities using those distance measurement methods as follows (p < 0.001): V1 ($60.9{\pm}2.7m/s$), V2 ($64.6{\pm}3.3m/s$), and V3 ($63.4{\pm}3.9m/s$). V2 was significantly greater than V1 and V3 (p < 0.001, p = 0.010, respectively). Conclusions: The distance measurement using a stopover point near the lateral epicondyle between two stimulus points in position of a fully extended elbow with forearm pronation is the most appropriate posture for radial motor NCS.

Facility Location Problem for Blood Logistics Center (혈액 물류센터 위치 선정 문제)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.12 no.2
    • /
    • pp.135-143
    • /
    • 2012
  • This paper suggests the optimal blood distribution center algorithm that satisfies the minimum total transportation cost and within the allowable distribution time $T^*$. Zhang and Yang proposes shifting the location of each point that has less than the average distance of two maximum distance points from each point. But they cannot decide the correct facility location because they miscompute the shortest distance. This algorithm computes the shortest distance $l_{ij}$ from one area to another areas. Then we select the $v_i$ area to thecandidate distribution center location such that $_{max}l_{ij}{\leq}L^*$ and the $v_i$ such that $l_{ij}-L^*$ area that locates in ($v_i,v_k$) and ($v_j,v_l$) from $P_{ij}=v_i,v_k,{\cdots},v_l,v_j$ path and satisfies the $_{max}l_{ij}{\leq}L^*$ condition. Finally, we decide the candidate distribution area that has minimum transportation cost to optimal distribution area.

Chest dimension in spontaneous pneumothorax (자연기흉 환자의 흉곽계측)

  • Kim, Jong-Won;Lee, Jong-Su
    • Journal of Chest Surgery
    • /
    • v.19 no.4
    • /
    • pp.750-759
    • /
    • 1986
  • Spontaneous pneumothorax is usually seen in young adult male. And typically, the patient is a tall, thin, 20- to 30-year-old male. Usually the pneumothorax results from rupture of a pulmonary bleb. Author reviewed 66 cases of spontaneous pneumothorax experienced in the Dept. of Thoracic & Cardiovascular Surgery, Pusan National University Hospital, since Jan., 1980 to Aug., 1986. The clinical data were summarized as follows: 1. The age distribution of spontaneous pneumothorax: 17 to 34 years old and mean age was 25.3 years. 2. The sex distribution of spontaneous pneumothorax: 52 in men, 14 in women and the ratio was 3.7:1. 3. Chest dimension in male patients: Maximum posteroanterior distance [MPA], MPA/Maximum width [MW]: Significantly smaller than control group. Distance from second to tenth rib on left [L2-10], Distance from second rib on right to diaphragm [R2-D], R2-D/MW: Significantly larger than control group. 4. Chest dimension in female patients: MPA, MW: Significantly smaller than control group. Distance from second rib on left to diaphragm [L2-D], Distance from second to tenth rib on right [R2-10], R2-D, L2-10/MW, L2-D/MW, R2-10/MW, R2-D/MW: Significantly larger than control group.

  • PDF

M-Estimation Functions Induced From Minimum L$_2$ Distance Estimation

  • Pak, Ro-Jin
    • Journal of the Korean Statistical Society
    • /
    • v.27 no.4
    • /
    • pp.507-514
    • /
    • 1998
  • The minimum distance estimation based on the L$_2$ distance between a model density and a density estimator is studied from M-estimation point of view. We will show that how a model density and a density estimator are incorporated in order to create an M-estimation function. This method enables us to create an M-estimating function reflecting the natures of both an assumed model density and a given set of data. Some new types of M-estimation functions for estimating a location and scale parameters are introduced.

  • PDF

The Minimum Squared Distance Estimator and the Minimum Density Power Divergence Estimator

  • Pak, Ro-Jin
    • Communications for Statistical Applications and Methods
    • /
    • v.16 no.6
    • /
    • pp.989-995
    • /
    • 2009
  • Basu et al. (1998) proposed the minimum divergence estimating method which is free from using the painful kernel density estimator. Their proposed class of density power divergences is indexed by a single parameter $\alpha$ which controls the trade-off between robustness and efficiency. In this article, (1) we introduce a new large class the minimum squared distance which includes from the minimum Hellinger distance to the minimum $L_2$ distance. We also show that under certain conditions both the minimum density power divergence estimator(MDPDE) and the minimum squared distance estimator(MSDE) are asymptotically equivalent and (2) in finite samples the MDPDE performs better than the MSDE in general but there are some cases where the MSDE performs better than the MDPDE when estimating a location parameter or a proportion of mixed distributions.

Algorithm for the Incremental Augmenting Matching of Min-Distance Max-Quantity in Random Type Quadratic Assignment Problem (랜덤형 2차원 할당문제의 최소 거리-최대 물동량 점진적 증대 매칭 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.22 no.3
    • /
    • pp.177-183
    • /
    • 2022
  • There is no known polynomial time algorithm for QAP that is a NP-complete problem. This paper suggests O(n2) polynomial time algorithm for random type quadratic assignment problem (QAP). The proposed algorithm suggests incremental augmenting matching strategy that is to set the matching set M={(li,fj)} from li with minimum sum of distance in location matrix L and fj with maximum sum of quantity in facility matrix F, and incremental augmenting of matching set M from M to li with minimum sum of distance and to fj with maximum sum of quantity. Finally, this algorithm performs swap strategy that is to reflect the complex correlations of distances in locations and quantities in facilities. For the experimental data, this algorithm, in spite of O(n2) polynomial time algorithm, can be improve the solution than genetic algorithm a kind of metaheuristic method.

Measurement of the local heat transfer coefficient on a convex hemispherical surface with round oblique impinging jet (볼록한 표면위에 분사되는 원형경사충돌제트의 국소열전달계수 측정에 관한 연구)

  • 최형철;이세균;이상훈;임경빈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.11 no.6
    • /
    • pp.846-854
    • /
    • 1999
  • Measurements of the local heat transfer coefficients were made on a hemispherically convex surface with a round oblique impinging jet. The liquid crystal transient method was used for these measurements. This method, which is a variation on the transient method, suddenly exposes a preheated wall to an impinging jet while video recording the response of liquid crystal for the surface temperature measurements. The Reynolds number used was 23000 and the nozzle-to-surface distance was L/d=2, 4, 6, 8, and 10 and the jet angle was $\alpha$=$0^{\circ}\; 15^{\circ}\;30^{\circ}C\; and \;40^{\circ}C$. In the experiment, the Nusselt number at the stagnation point decreases as the jet angle increases and has the maximum value for L/d=6. The X-axis Nusselt number distributions exhibit Secondary maxima at $0^{\circ}C\re $\alpha$\re 15^{\circ}C, L/d\le6$ for X/d<0(upstream) and at $0^{\circ}C\re $\alpha$40^{\circ}C,\;L/d\le4\;and\; at\; 30^{\circ}C\re $\alpha$$\leq$40^{\circ}C,\;L/d\le 6 $for X/d>0(downstream). The secondary maxima occurs at long distance from the stagnation point as the jet angle increases or the nozzle-to-surface distance decreases. The Y-axis Nusselt number distributions exhibit secondary maxima at Y/d=$\pm$2 for $0^{\circ}C\le a\le30^{\circ}C\; and\; L/d\le4, and \;for\;$\alpha$=40^{\circ}C$and L/d=2. The displacement of the maximum Nusselt number from the stagnation point increases as the jet angle increases or the nozzle-to-surface distance decreases and the maximum distance is about 0.67 times of the nozzle diameter. The ratio of the maximum Nusselt number to the stagnation Nusselt number increases as the jet angle increases.

  • PDF

Evaluation of the Sterilization Effect of a Plasma Generator with a Flexible Electrode Structure on Staphylococcus aureus and Pseudomonas aeruginosa (황색포도알균과 녹농균에 대한 유연전극 구조를 갖는 플라즈마 발생기의 멸균효과 평가)

  • Park, Chul;Lee, Hyeok Jae
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.52 no.4
    • /
    • pp.372-380
    • /
    • 2020
  • In this study, the sterilization ability of S. aureus and P. aeruginosa was evaluated using a plasma generator with a flexible electrode structure. Both strains were prepared at a concentration of 1.5×106 CFU/mL and inoculated and spread evenly on two medium plates. The medium were kept at a distance of 3 cm and 9 cm from the plasma generator and were plasma discharged from 30 sec to 10 minutes. The growth of colonies on the media, were subsequently compared with the control group. The mean colonies of S. aureus formed at a 3 cm distance were 9.2×102 (log value 2.96) CFU/mL for the 5 min discharge period and 8.0×10 (1.90) CFU/mL for the 10 min discharge period. When the medium was exposed for 5 min and 10 min at a 9 cm distance, the mean colonies of S. aureus formed were 2.16×103 (3.33) and 2.4×102 (2.38) CFU/mL, respectively. The medium containing P. aeruginosa kept at a 3 cm distance and exposed to 3, 5, 10-minute discharge, did not form any colonies. When kept at a 9 cm distance for 3 minutes, 6.0×102 (2.78) CFU/mL mean colonies were formed but no colonies were formed at exposure periods of 5 and 10 minutes. This enhanced sterilization effect was confirmed in experiments of S. aureus and P. aeruginosa using TiO2.