• Proceeding of EDISON Challenge
• /
• 2013.04a
• /
• pp.393-397
• /
• 2013

관내의 유량을 제어하는 볼 밸브(ball valve)는 개폐각도(opening degree)가 커짐에 따라 출구에서 유속이 증가하고 밸브(valve)의 입 출구 간 압력강하(pressure drop)가 증가한다. 출구에서의 압력이 작동유체의 포화증기압보다 낮아질 때 공동현상(cavitation)이 발생한다. 관내에서의 공동현상은 배관시스템의 진동 및 소음, 부식 등에 있어서 악영향을 미칠 수 있으므로 설계에 매우 중요한 요소이다. 버터플라이 밸브를 비롯한 다른 밸브에서는 공동현상감소에 대한 연구가 많이 이루어졌다. 이에 본 연구에서는 볼 밸브 내 유동 특성(characteristic of flow)과 볼 밸브의 입출구간 압력강하를 줄이는 연구를 수행하였다. 개폐 각도와 그에 따른 압력강하와의 관계를 Edison_전산열유체를 사용하여 분석하고 공동현상을 감소시킨 볼 밸브의 설계를 제시 하였다.

• Journal of Korean Society on Water Environment
• /
• v.25 no.2
• /
• pp.281-287
• /
• 2009

Achieved monitoring regularly about fishway that is a intake dam belongings to Kyeongchon for 5 years. Result that achieve monitoring, discovered pressing issue of opening and closing degree of discharge control part in fishway. In this research, analyze discharge relation with fishway and intake sluice and presented operation plan of opening and closing of discharge control part. Investigated necessity intake discharge and benefited area to analyze relation of discharge that is flowed in fishway and discharge escaping by intake sluice. When opened discharge control part step by step gradually, analyzed discharge. Compared with survey discharge making ration curve of fishway and intake sluice using orifice and submerged weir formula. Because operation of intake dam is necessary intake discharge and upriver inflow discharge by time, operation uses by survey discharge and calculated opening discharge of fishway by opening discharge of intake sluice via monthly inflow discharge. To sum up, calculated floodgate opening height of fishway by water level to present maintenance standard of intake dam.

• Journal of Oral Medicine and Pain
• /
• v.15 no.1
• /
• pp.79-89
• /
• 1991

The author examined the patterns and various ranges of mandibular movements in TMJ lock closed patients in the frontal, sagittal and horizontal plane and obtained the following results. 1. In the frontal trajectory, the mean amount of maximum mouth opening was 24.4mm and the opening paths were deviated to the affected side in 87.1% of the patients. The mean amount of maximum laterotrusion to the affected side was 10.4mm and that of non-affected side was 7.5mm. There was a significant difference between them(p<0.001). 2. In the sagittal trajectory, the mean amount of the maximum protrusion was 7.0mm, the mean amount of the maximal retrusion was 1.0mm 3. In the horizontal trajectory, the pattern of laterotrusion showed asymmetry: the mean length of non-affected side was smaller than that of the affected side. Protrusive path were deviated to the affected side in 64.5% of the patients, the mean degree of deviation was 16.4$^{\circ}$. The mandibular movements of TMJ lock-closed patients can be characterized by decreased range of mouth opening, protrusive movement, and laterotrusive movement to the non-affected side and also characterized by deviated opening and protrusive path to the affected side.

• Journal of The Geomorphological Association of Korea
• /
• v.28 no.4
• /
• pp.1-13
• /
• 2021

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.

• Advances in concrete construction
• /
• v.6 no.3
• /
• pp.245-268
• /
• 2018

The numerical investigations have been carried out on deep beam with opening subjected to static monotonic loading to demonstrate the accuracy and effectiveness of the finite element based numerical models. The simulations were carried out through finite element program ABAQUS/CAE and the results thus obtained were validated with the experiments available in literature. Six simply supported beams were modelled with two square openings of 200 and 250 mm sides considered as opening at centre, top and bottom of the beam. In order to define the material behaviour of concrete and reinforcing steel bar the Concrete Damaged Plasticity model and Johnson-Cook material parameters available in literature were employed. The numerical results were compared with the experiments in terms of ultimate failure load, displacement and von-Mises stresses. In addition to that, seventeen beams were simulated under static loading for studying the effect of opening location, size and shape of the opening and depth, span and shear span to depth ratio of the deep beam. In general, the numerical results accurately predicted the pattern of deformation and displacement and found in good agreement with the experiments. It was concluded that the structural response of deep beam was primarily dependent on the degree of interruption of the natural load path. An increase in opening size from 200 to 250 mm size resulted in an average shear strength reduction of 35%. The deep beams having circular openings undergo lesser deflection and thus they are preferable than square openings. An increase in depth from 500 mm to 550 mm resulted in 78% reduced deflection.

• The Journal of Korean Medicine
• /
• v.20 no.1 s.37
• /
• pp.106-112
• /
• 1999

The purpose of this study is to investigate the effects of Bee Venom Herb-Acupuncture on the jaw opening reflex evoked by tooth pulp stimulation. Rats were anesthetized with thiopental sodium given intraperitoneally in an initial dose of 80mg/kg. Maintenance doses of 5mg/kg thiopental sodium were given through a cannular in the femoral vein as required to maintain light anesthesia. To apply noxious stimuli, a pair of enameled wires were inserted into the tooth pulp of the lower incisor. The effects of conditioning stimuli were estimated as an indicator of the degree of suppression of the digastric muscle electromyogram(dEMG) in the jaw opening reflex. Bee Venom Herb- Acupuncture(0.2% solution 0.1ml/rat) was injected to Hapgok(LI4) loci. In addition, Normal Saline (0.1ml/rat) was injected to Hapgok loci so as to compare the degree of suppression elicited from Bee-Venom. By administration of Bee Venom Herb-Acupuncture, the amplitude of dEMG was maximally suppressed to $67.5{\pm}3.38%$ ipsilaterally, 73.33{\pm}8.00%$ contralaterally. Generally, the dEMG activities caused by electrical stimulation were gradually suppressed during the stimulation and maximal suppressive effect showed at 15min after its onset. However the dEMG activities by Be Venom Herb-Acupuncture were immediately suppressed after its onset and the suppressive effect continued for a long time compared to electrical stimulation. In conclusion, Bee Venom Herb-Acupuncture may have a different mechanism of analgesia from that of electro-acupuncture and contribute to the modulation of pain analgesia.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.41
• /
• pp.44.1-44.7
• /
• 2019

Background: We evaluated the improvement of pain and the increase in mouth opening after temporomandibular joint arthrocentesis and the possible association with various factors such as previous splint treatment, medication, and diagnosis. Results: We studied 57 temporomandibular joint disorder patients who underwent arthrocentesis at Korea University Anam Hospital. These patients (24 males and 33 females, aged between 15 and 76 years) underwent arthrocentesis that was performed by one surgeon. The degree of mouth opening (assessed using the maximum mouth opening: MMO) and pain (assessed using the visual analog scale: VAS) were assessed pre- and post-arthrocentesis. The study also investigated whether treatment modalities other than arthrocentesis (medication and appliance therapy) were performed. Statistical analysis revealed that there was a significant difference in mouth opening and pain after temporomandibular joint arthrocentesis. Preoperative appliance therapy affected the results of arthrocentesis, but it was not statistically significant. With regard to pain relief, preoperative diagnosis did not show a significant difference. However, with regard to maximum mouth opening, patients with disc displacement without reduction with limited mouth opening (closed lock) showed the highest recovery (11.13 mm). Conclusion: The average of MMO increase after arthrocentesis was 9.10 mm, and patients with disc displacement without reduction with locking (closed lock) showed most recovery in maximum mouth opening and it was statistically significant. The average pain relief of patients after arthrocentesis was 3.03 in the VAS scale, and patients using anterior repositioning splint (ARS) preoperatively showed the most pain relief.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.1
• /
• pp.73-80
• /
• 2015

The valve device is installed in hazardous areas, such as a chemical plant explosion has been sealed with fire protection device to prevent the risk of explosion. In this paper, due to the explosion-proof devices using external power the device can not be used in infrared sensors and Zigbee sensor valve device by measuring the open degree of valve opening and closing of the danger zone to check whether. Valve opening and closing operation log screen time, we propose a low-power operation monitoring system administrators to manage and control the plant. Develop power control relay board apply an improved algorithm to apply the asynchronous LPL power management. The plant monitoring system and explosion-proof valve opening and closing the valve system with the intelligent device designed and implemented and tested it.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.17 no.1
• /
• pp.223-232
• /
• 1987

The author obtained the transcranial-oblique lateral radiograms from 78 patients(26 male, 52 female) with temporomandibular dysfunction problem. And then, the author analyzed the dimensional changes of the TMJ space on centric occlusion, horizontal condylar movement and antero-posterior positional relationship of condyle to the articular eminence on 2.54㎝ mouth opening with clicking, TMJ pain and mouth opening limitation repectively, which were the symptoms of the temporomandibular joint pain dysfunction problem, and compared these data with control group. The results were as follows: 1. In centric occlusion, anterior and posterior TMJ space of experimental group was slightly lesser than those of the control group, also superior TMJ space of experimental group was significantly lesser than that of the control group. (p<0.01) 2. In 2.54㎝ mouth opening, the condylar horizontal movement and the antero-posterior positional relationship to the articular eminence were significantly lesser than those of the control group. (p<0.01) 3. Examined experimental group, the degree of condylar horizontal movement of affected ide was lesser than that of the normal side in 2.54㎝ mouth opening.

• Journal of Industrial Technology
• /
• v.21 no.A
• /
• pp.7-14
• /
• 2001

In building structure, the story height can be minimized by providing openings in beams which serves for the utility equipments passing through. The dead space in false ceiling thus put to economical use in the form of a substantial reduction in materials and construction cost. In the case of steel structure, there is no critical risk in the structural strength because of reinforcing methods of stiffness and steel plate but in the case of reinforced concrete structure, proper provision should be made in designing these openings, otherwise there is a risk that these opening will possibly weaken the structural strength of the building frame to a critical degree. In this paper, for the numerical analysis of the reinforced concrete beams with circular opening in the web, expecting stress concentration of the circular opening, reinforcing methods were studied. Twenty test pieces with each different reinforcing methods were tested and their resisting forces were defined. From the numerical analysis and test results, the followings were founded;(1)high shear stress distributed around the openings reduce the shearing strength, (2)from the numerical analysis, the maximum tensile stress occurred at opening nodes 1,7, these phenomena were agreed with the test results, (3)reinforcing method around openings have to carried out for stopping diagonal cracks, and (4)both, by steel plate, and wire mesh, are effective reinforcing methods.