• Title/Summary/Keyword: wall-following

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Development of Evaluation Technique of Mobility and Navigation Performance for Personal Robots (퍼스널 로봇을 위한 운동과 이동 성능평가 기술의 개발)

  • Ahn Chang-hyun;Kim Jin-Oh;Yi Keon Young;Lee Ho Gil;Kim Kyu-ro
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.2
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    • pp.85-92
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    • 2003
  • In this paper, we propose a method to evaluate performances of mobile personal robots. A set of performance measures is proposed and the corresponding evaluation methods are developed. Different from industrial manipulators, personal robots need to be evaluated with its mobility, navigation, task and intelligent performance in environments where human beings exist. The proposed performance measures are composed of measures for mobility including vibration, repeatability, path accuracy and so on, as well as measures for navigation performance including wall following, overcoming doorsill, obstacle avoidance and localization. But task and intelligent behavior performances such as cleaning capability and high-level decision-making are not considered in this paper. To measure the proposed performances through a series of tests, we designed a test environment and developed measurement systems including a 3D Laser tracking system, a vision monitoring system and a vibration measurement system. We measured the proposed performances with a mobile robot to show the result as an example. The developed systems, which are installed at Korea Agency for Technology and Standards, are going to be used for many robot companies in Korea.

Total Spinal Block for Treatment of Post-traumatic Cervical Syndrome (외상성 경부 증후군의 치료를 위한 전척수신경차단의 효과)

  • Chang, Won-Young;Yoon, So-Young;Kim, Kyung-Bae;Choe, Kun-Chun
    • The Korean Journal of Pain
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    • v.6 no.1
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    • pp.109-116
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    • 1993
  • In March of l992, We performed two intentional total spinal blocks for the relief of pain. This was for 2 cases of post-traumatic cervical syndrome whose various symptoms were chronically unresponsive to the usual conservative treatments. We regularly checked the blood pressure, pulse rate, oxygen saturation and observed clinically the changes of respiration, consciousness, lid and light reflexes during the total spinal block. Pain relief was evaluated by using the Visual Analog Scale which is designed to measure the subjective intensity of pain. The results were as follows; 1) The effectiveness of total spinal block was 60% in case 1, 40% in case 2. 2) We observed two complications from the procedure. Firstly during the block, these were transient periods of hypotension. Following the block, accidental procedures related direct neural trauma resulted in anterior chest wall pain. In conclusion we believe that total spinal block is a satisfactory and reliable method for the treatment of post-traumatic cervical syndrome.

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Traumatic Displacement of the Globe into the Maxillary Sinus: Case Report (외상성 상악동 안구탈출의 치험례: 증례보고)

  • Lim, Chan Soo;Kang, Dong Hee
    • Archives of Plastic Surgery
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    • v.34 no.4
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    • pp.524-527
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    • 2007
  • Purpose: Globe displacement due to a blowout fracture is a rare clinical phenomenon. The authors present reduction of a globe displacement to the maxillary sinus due to trauma suffered in a fall and the reconstruction of a large defect left in the medial and inferior orbit. Methods: A 39-year-old male patient was unable to open his left eye after being struck on the periorbital area by a metal edge. Laceration was not noted in that area but we were unable to observe the intraorbital globe. A facial computed tomography (CT) scan showed that the globe was displaced through the maxillary sinus. A transconjunctival approach was used to access the infraorbital margin and the globe entrapped in the inferior margin of the orbit was successfully reduced. A large defect in the medial and inferior orbit was reconstructed using a graft from the iliac bone. Results: In 5 months after the operation, no atrophy of the globe was seen. Both sides retained a similar shape. A satisfactory functionality outcome in terms of improved extraocular muscle movement, and a satisfactory aesthetical outcome were achieved. Conclusion: The authors report the reduction of a globe displaced to the maxillary sinus following a fall and the reconstruction of the large defect left in the medial and inferior orbit.

Pre- and Postoperative Hemodynamic Studies in the Patients with Constrictive Pericarditis (수축성 심막염에 대한 심막절제술 전후의 수술방법에 따른 혈역학적 비교)

  • 조인택
    • Journal of Chest Surgery
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    • v.19 no.1
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    • pp.68-74
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    • 1986
  • 15 patients with constrictive pericarditis who underwent interphrenic pericardiectomy from January, 1981 to April, 1983 and 11 patients who underwent radical pericardiectomy from May, 1983 to September, 1984 were compared to the clinical improvement and the results of pre- and postoperative cardiac catheterization. In the group of partial pericardiectomy the pericardium was removed anteriorly from the left phrenic nerve to the right phrenic nerve and in the group of radical pericardiectomy the pericardium was removed from almost entire surface of the heart including diaphragmatic surface and posterior wall of the left ventricle. The following results were obtained. 1. Both group of the patients showed marked symptomatic improvement early after operation. 2. The central venous pressure was decreased significantly after operation in both group of the patients. 3. The right atrial mean pressure and pulmonary arterial mean pressure decreased significantly after operation in both group of the patients and there was no significant difference in the amplitude of decrease between the two groups. 4. The right ventricular end-diastolic pressure and left ventricular end-diastolic pressure were decreased postoperatively in both group of the patients and the patients of the radical pericardiectomy showed more decrease than the patients of interphrenic pericardiectomy, and in the group of radical pericardiectomy the right and left ventricular end-diastolic pressure were normalized postoperatively but in the group of partial pericardiectomy they showed abnormally high pressure persistently. 5. The ejection fraction showed normal level pre- and postoperatively in both group of the patients.

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A Case of Equine Uterine Angioleiomyoma

  • Jang, Seong-Hwan;Kim, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.33 no.5
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    • pp.316-319
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    • 2016
  • A 12-year-old thoroughbred mare with four days history of anorexia and high fever was submitted to the Equine Hospital. She failed to conceive in the following the breeding season in spring. In rectal palpation, mass could be palpable surrounding ovary. Because of the poor prognosis, full necropsy for mare was decided. The mass is located between right large and small colon, cranial to ovary using ultrasonography. Grossly, the mass was about $5{\times}3.5{\times}4cm$ in size, and the cut surface of mass showed brownish yellow in color with red-to orange granular areas Histopathologically, neoplastic cells were mixed with well differentiated spindle shape cells arranged in interlacing, interwoven pattern and poorly differentiated spindle cells. Neoplastic cells had abundant pink cytoplasm and bland and cigar-shaped nuclei with low mitotic figures. Many arteriole-like blood vessels with thick muscular wall were present throughout the mass. Masson's trichrome staining revealed muscle origin tumors in this case. Immunohistochemically, the neoplastic spindle cells showed positive reactions for smooth muscle actin and desmin. In our best knowledge, this is the first report of uterine angioleiomyoma in mare in Korea.

Condensation Heat Transfer Characteristics of Non-Azeotropic Refrigerant Mixture(NARMs) Inside Double Pipe Heat Exchangers (2중 관형 열교환기내 비공비혼합냉매 R-22+R134a의 응축열전달 특성에 관한 연구)

  • 노건상;오후규;권옥배
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.3
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    • pp.91-100
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    • 1996
  • Experimental results for forced convection condensation of non-azeotropic refrigerant mixtures inside a horizontal smooth tube are presented. The mixtures of R-22+R-134a and pure refrigerants R-22 and R-134a are used as the test fluids and a double pipe heat exchanger of 7.5mm ID and 4800mm long inside tube is used. The range of parameters are 100-300kg/h of mass flow rate, 0-1.0 of quality, and 0, 33, 50, 67, and 100 weight percent of R-22 mass fraction in the mixtures. The heat flux, vapor pressure, vapor temperature and tube wall temperature were measured. Using the data, the local and average heat transfer coefficients for the condensation have been obtained. In the same given experimental conditions, the liquid heat transfer coefficients for NARMs were considerally lower than that of the pure refrigerant of R-22 and R-134a. Local heat transfer characteristics for NARMs were different from pure refrigerant R-22 and R-134a. In some regions, local heat transfer coefficients for NARMs were increased in the following order ; Bottom$\rightarrow$Top$\rightarrow$Side. The condensation heat transfer coefficients for NARMs increased with mass velocity, heat flux, and quality, but were considerably lower than that of pure refigerant R-22 and R-134a.

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The effect of infill walls on the seismic behavior of boundary columns in RC frames

  • Fenerci, Aksel;Binici, Baris;Ezzatfar, Pourang;Canbay, Erdem;Ozcebe, Guney
    • Earthquakes and Structures
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    • v.10 no.3
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    • pp.539-562
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    • 2016
  • The seismic behavior of a ${\frac{1}{2}}$ scaled, three-story three-bay RC frame with masonry infill walls was studied experimentally and numerically. Pseudo-dynamic test results showed that despite following the column design provisions of modern seismic codes and neglecting the presence of infill walls, shear induced damage is unavoidable in the boundary columns. A finite element model was validated by using the results of available one-story one-bay frame tests in the literature. Simulations of the examined test frame demonstrated that boundary columns are subjected to shear demands in excess of their shear capacity. Seismic assessment of the test frame was conducted by using ASCE/SEI 41-06 (2006) guidelines and the obtained results were compared with the damage observed during experiment. ASCE/SEI 41-06 method for the assessment of boundary columns was found unsatisfactory in estimating the observed damage. Damage estimations were improved when the strain limits were used within the plastic hinge zone instead of column full height.

Delayed-type retrobulbar hematoma caused by low temperature after reconstruction of inferior blow-out fracture

  • Lee, Da Woon;Kim, Tae Hyung;Choi, Hwan Jun;Wee, Syeo Young
    • Archives of Craniofacial Surgery
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    • v.22 no.2
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    • pp.110-114
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    • 2021
  • Retrobulbar hemorrhage is a disastrous condition that can lead to permanent blindness. As such, rapid diagnosis and treatment are critical. Here, we report a patient who presented with retrobulbar hemorrhage following an orbital floor fracture. Restoration of inferior orbital wall with porous polyethylene implant was underwent. Four days after the orbital floor reconstruction, the patient smoked a cigarette outdoors in -3℃ weather. Cold temperature and smoking caused an increase in his systemic blood pressure. The elevated blood pressure increased intraorbital pressure to the extent of causing central retinal artery occlusion and exacerbated oozing. During exploratory surgery, 3 mL of hematoma and diffuse oozing without arterial bleeding were observed. Prompt diagnosis and treatment prevented vision impairment. Few studies have reported on the risk factors for retrobulbar hemorrhage. This case showed that daily activities, such as exposure to cold weather or tobacco smoking, could be risk factors for retrobulbar hemorrhage.

Anatomical Structures and Fiber Quality of Four Lesser-Used Wood Species Grown in Indonesia

  • MARBUN, Sari Delviana;WAHYUDI, Imam;SURYANA, Jajang;NAWAWI, Deded Sarip
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.5
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    • pp.617-632
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    • 2019
  • This study aimed to investigate the anatomical structure and fiber quality of four lesser-used wood species namely Benuang (O. sumatrana), Duabanga (D. moluccana), Pisang Merah (H. hellwigii), and Terap (A. odoratissimus). This study evaluated its suitability for raw material in pulp and paper manufacturing. The anatomical structure was observed macro- and microscopically. Macroscopic structures were observed directly to the wood samples, while microscopic characteristics were observed through microtome specimens. Fiber dimension was measured through macerated specimens and fiber quality was analyzed following the Rachman and Siagian's method. Results showed that these four timber species have similarity in the indistinct growth ring, diffuse porous in a radial pattern, rounded solitary vessel outline, 1 to 3 cells of ray width, deposits within the rays, fiber length, and cell wall thickness. Differences were found on vessel diameter, vessel grouping, vessel frequency, tyloses existence, type of axial parenchyma, and ray height. Based on fiber length and its derived values, the wood fibers of all species studied are suitable for pulp and paper manufacturing. They belong to the II quality class. The produced pulp and paper would have good quality, especially in tensile, folding, and tear strength. To promote their utilization, silviculture aspect of these four species has to be well understood.

Wind loads and wind-resistant behaviour of large cylindrical tanks in square-arrangement group. Part 2: CFD simulation and finite element analysis

  • Liu, Qing;Zhao, Yang;Cai, Shuqi;Dong, Shilin
    • Wind and Structures
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    • v.31 no.6
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    • pp.495-508
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    • 2020
  • To investigate the structural behaviour of grouped tanks under wind loads, 2 problems need to be figured out, wind pressures on tank shells and critical loads of the shell under these pressure distribution patterns. Following the wind tunnel tests described in the companion paper, this paper firstly seeks to obtain wind loads on the external wall in a squarely-arranged cylindrical tank group by numerical simulation, considering various layouts. The outcomes demonstrate that the numerical method can provide similar results on wind pressures and better insights on grouping effects through extracted streamlines. Then, geometrically nonlinear analyses are performed using several selected potentially unfavourable wind pressure distributions. It is found that the critical load is controlled by limit point buckling when the tank is empty while excessive deformations when the tank is full. In particular, significant reductions of wind resistance are found on grouped full tanks compared to the isolated tank, considering both serviceability and ultimate limit state, which should receive special attention if the tank is expected to resist severe wind loads with the increase of liquid level.