• Journal of the Society of Naval Architects of Korea
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• v.51 no.3
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• pp.259-264
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• 2014

Tip vortex cavitation (TVC) is important for naval ships and research vessels that require raising the cavitation inception speed to maximum possible values. The concepts for alleviating the tip vortex are summarized by Platzer and Souders (1979), who carried out a thorough literature survey. Active control of TVC involves the injection of a polymer or water from the blade tip. The main effect of such mass injection (both water and polymer solutions) into the vortex core is an increase in the core radius, consequently delaying TVC inception. However, the location of the injection port needs to be selected with great care in order to ensure that the mass injection is effective in delaying TVC inception. In the present study, we propose a semi-active control scheme that is achieved by attaching a thread at the propeller tip. The main idea of a semi-active control is that because of its flexibility, the attached thread can be sucked into the low-pressure region closer to the vortex core center. An experimental study using a scale model was carried out in the cavitation tunnel at the Seoul National University. It was found that a flexible thread can effectively suppress the occurrence of TVC under the design condition for a model propeller.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.368-374
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• 2015

On the basis of vegetation data by point quarter sampling method, the natural forest of Jirisan(Mt.) was classified into eight forest types by cluster analysis. They were Quercus mogolica forest type, Fraxinus mandshurica - Betula costata forest type, Mixed mesophytic forest type, Abies koreana forest type, Carpinus laxiflora forest type, Quercus serrata forest type, Pinus densiflora forest type, and Quercus variabilis forest type. Then, succession index was estimated for each forest type so as to evaluate succession process comparatively among forest types. The results showed that Carpinus laxiflora forest type had highest succession index of 219.7, followed by Mixed mesophytic forest type with little difference of the index of 218.3. Pinus densiflora forest type had lowest index. Succession indices were hardly correlated with species diversity indices of forest types. We presumed that the higher value of succession index a forest type had, the closer toward the climax forest. However, the estimated index was not supposed to be absolute level of successional stage, but it could play a role of comparative assessment in the position of the seral stage among forest types.

• Clinics in Shoulder and Elbow
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• v.1 no.2
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• pp.250-255
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• 1998

Purpose of the study was to analyze the supraspinatus outlet image of sagittal MRI in rotator cuff disease. We analyzed the sagittal views of the shoulder MRI of 78 cases without cuff tear. The cases were divided into 51 cases of rotator cuff disease group and 27 cases of control group. Six parameters of acromial tilt, coracoacromial ligament angle, length and height of coracoacromial triangle, length of acromial side of the baseline and distance of intrusion of the humeral head were compared for each group. The distance of intrusion of the humeral head was the most significantly different one, 0.52cm for rotator cuff disease group and 0.15cm for control group. Intrusion of the humeral head to the supraspinatus outlet space from the bottom may be a contributing factor developing rotator cuff disease. The intrusion may precede to tearing of the rotator cuff.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.523-528
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• 1998

The electrochemical characteristics of $V_2O_5$ as working electrode were studied in the cell (1-butene+$O_2$, $V_2O_5{\mid}YSZ{\mid}Ag$, $O_2$) with a YSZ solid electrolyte. The sintering of Ag as a counter electrode was occurred after calcination, and the structure which has the pores of over $3{\mu}m$ was achieved. In particular, the peak of (010) plane of the working electrode on the XRD spectrum which is responsible for selective oxidation appeared after calcination. The major product of 1-butene oxidation over $V_2O_5$ was butadiene. The technique of SEP (solid electrolyte potentiometry) was used to monitor the chemical potential of chemical species adsorbed on the working electrode. Over a wide range of gas compositions of 1-butene and oxygen, open circuit voltage (OCV) exhibited the mixed potential of surface oxygen activity.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.2
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• pp.171-177
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• 2014

A two-dimensional particle image velocimetry (2D PIV) system in a towing tank is employed to measure a wake field of a very large crude oil carrier model with rotating propeller in self propulsion condition, to identify characteristics of wake of a propeller working behind a ship. Phase-averaged and time-averaged flow fields are measured for a horizontal plane. Scale ratio of the model ship is 1/100 and Froude number is 0.142. By phase-averaging technique, trajectories of tip vortex and hub vortex are identified and characteristic secondary vortex distribution is observed in the hub vortex region. Propeller wake on the starboard side is more accelerated than that on the port side, due to the difference of inflow of propeller blades. The hub vortex trajectory tends to face the port side. With the fluctuation part of the phase-averaged velocity field, turbulent kinetic energy (TKE) is also derived. In the center of tip vortex and hub vortex region, high TKE concentration is observed. In addition, a time-averaged vector field is also measured and compared with phase-averaged vector field.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.1 no.2
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• pp.112-116
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• 2008

Ultrasonography of shoulder joint recently enlarges its utility since the knowledge of the shoulder disease is increased by numerous researches. Ultrasonography is not only noninvasive, safe, and relatively cheap, but also an unique modality that can monitor tendon movement during shoulder motion. Sonographic examination generally starts from the front side of the shoulder joint and finishes at back side in sitting position. Many structures in shoulder joint such as muscles, ligaments, glenoid labrum, bone, and especially rotator cuff tendon can be examined by ultrasonography. The rotator cuff is a motion unit consisted with subscapularis, supraspinatus, infraspinatus, and teres minor muscles. It functions as fulcrum and compresses the humeral head onto the glenoid, and steers for shoulder joint.

• Journal of Haehwa Medicine
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• v.26 no.1
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• pp.73-80
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• 2017

Objectives : The purpose of this research is to show the effectiveness of the Korean medical treatment on patients diagnosed with supraspinatus tendinosis, subacromial bursitis and subdeltoid bursitis treated by Korean medical treatment Including megadose shinbaro pharmacopuncture. Methods : We used megadose shinbaro pharmacopuncture on patients who received treatment at Bucheon Jaseng Korean medicine hospital from December, 2016 to January, 2017. Also we checked NRS, SPADI, range of motion(ROM) and shoulder physical examination to follow the scale showing the improvement of the symptoms of the patients. Results : All 4 patientes showed the improvement of NRS, SPADI range of motion(ROM) and shoulder physical examination. Conclusion : This research showed that megadose shinbaro pharmacopuncture was effective on the treatment of shoulder pain patients diagnosed with supraspinatus tendinosis, subacromial bursitis and subdeltoid bursitis.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.4
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• pp.161-167
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• 2015

Objectives The objective of this study is to report the improved case of Korean medicine treatment with Shinbaro3 pharmacopuncture for supraspinatus tendinitis and subdeltoid bursitis. Methods We used Shinbaro3 pharmacopuncture with other Korean medicine treatment (acupuncture, herbal medicine, cupping and chuna) for this patient. This case is measured and assessed by Numerical Rating Scale (NRS), shoulder range of motion (ROM) and shoulder physical examination. Results The NRS decreased from 10 to 2 and the patient showed nearly full shoulder range of motion. Also physical examination of shoulder was improved. Conclusions Korean medicine treatment with Shinbaro3 pharmacopuncture is proved to be helpful to relieve pain and recover function on shoulder joint.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.378-383
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• 2000

Pinus sylvestris plantations in the Eifel mountains, Germany, were studied and classified phytosociologically. Ecological characteristics(soil, natural regeneration & succession) of the plant communities classified were analyzed and described with emphasis on the forest management. According to soil and topographic characteristics, this plantations were divided into four categories ; Vaccinium myrtillus-Pinus sylvestris community of the adequate moisture area, Pteridium aquilium-Pinus sylvestris community of the moisture area, Molinia caerulea-Pinus sylvestris community of the hardened soil layer B and Festuca tenuifolia-Pinus sylvestris of the dry area. Tree species growing below the shrub layer was analyzed. The results were considered as Vaccinium mytillus-Pinus sylvestris, Pteridium aquline-Pinus sylvestris and Molinia caerulea-Pinus sylvestris will be changed into Fagus sylvatica forest following Quercus forest, and Festuca tenuifilia-Pinus sylvestris will be changed into Pinus sylvestris-dominated climax forest.

• Korean Journal of Environment and Ecology
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• v.4 no.1
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• pp.23-32
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• 1990

To investigate the structure of the pine forest community and the conservation of pine forest in Mt. Sokri, twenty plots of 500$m^2$ size set up by the clumped sampling method. The classification by TWINSPAN and DCA ordination were applied to the study area in order to classify them into several groups based on environmental variables. The plant community was not classified into several groups by above methods in this study area. The successional trends of tree species by both techniques seem to be from Pinus densiflora through Quercus serrata, Fraxinus sieboldiana, Q. aliena, Sorbus alnifolia, Prunus sargentii to Carpinus laxiflora, C. cordata in the canopy layer. and from Rhus trichocarpa, Lindera obtusiloba through Styrax obassia, Acer pseudosieboldiana, Symplocos chinensis for. pilosa to L. erythrocarpa, Viburnum erosum in the understory layer. Pinus densiflora community shall be conserved by the disclimax method, i. e. the broadleaf vegetation in the underlayer of the pine community should be cleared out.