• Journal of Power Electronics
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• v.13 no.2
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• pp.296-303
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• 2013

This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.54-61
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• 2008

This paper proposes a new algorithm for detecting and recognizing overlapped objects among a stack of arbitrarily located objects using a signature representation scheme. The proposed algorithm consists of two processes of detecting overlap of objects and of determining the boundary between overlapping objects. To determine overlap of objects, in the first step, the edge image of object region is extracted and those areas in the object region are considered as the object areas if an area is surrounded by a closed edge. For each object, its signature image is constructed by measuring the distances of those edge points from the center of the object, along the angle axis, which are located at every angle with reference to the center of the object. When an object is not overlapped, its features which consist of the positions and angles of outstanding points in the signature are searched in the database to find its corresponding model. When an object is overlapped, its features are partially matched with those object models among which the best matching model is selected as the corresponding model. The boundary among the overlapping objects is determined by projecting the signature to the original image. The performance of the proposed algorithm has been tested with the task of picking the top or non-overlapped object from a stack of arbitrarily located objects. In the experiment, a recognition rate of 98% has been achieved.

• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.51-56
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• 2009

Purpose: This study examined the difference in the static balance ability according to the visual cues and postural tasks in normal subjects. Methods: Thirty participants (12 male, 18 female; mean age $24.63\pm1.43$ years) stood barefoot on a force platform in a one-legged stance, tandem Romberg stance and tandem Romberg with neck extension stance with a visual cue open and closes. The static balance was assessed by the center of pressure (CoP), surface electromyography root mean square (RMS) of the leg muscles according to the stance position. Results: In the CoP tests, the difference in the unit path length and circumference area was affected by the visual cue according to the stance posture (p<0.01). In the RMS tests, the difference in the tibialis anterior and medial gastrocnemius muscle was affected by visual cue in accordance with the stance posture (p<0.01). Conclusion: The visual cue and postural task affect the balance ability in normal subjects. Therefore, this study provides clinical evidence that the balance and postural control can be improved. Therapeutic intervention, such as an obstacle course, and a lower leg muscle performance program with a change in the base of support can affect the balance and postural control.

• Journal of fish pathology
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• v.22 no.2
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• pp.163-166
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• 2009

The ectoparasite ciliate Trichodina has been recorded from above 100 species of freshwater and marine fishes. In April 2009, we investigated the trichodia infection in 13 species of marine fishes captured by emplacement net and gill net in order to understand trichodina infection status among the natural fish populations along the Namhae-Gun coast area, the southen coast of Korea. Trichodina infection was observed in 10 out of 10 sea basses Lateolabrax japonicus, 2 out of 5 finespotted flounder Pleuronichthys cornutus and 1 out of a stone flounder Kareius bicoloratus. The sea bass infected with the parasite showed hypertrophy and exfoliation in gill epithelium. In addition, hyperplasia and lamellar fusion of gill filament were noticed among naturally affected sea bass.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.914-922
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• 2004

In this study, measurement and analysis of energy consumption of a research building have been conducted. The energy audit procedure includes monitoring of electricity and LNG consumption over a period of three yews from 2000 to 2002. Data acquisition system for collecting energy consumption data of HVAC equipment such as chillers, fan filter units, AHUs, cooling towers, boilers, pumps, fan coil units, air compressors and etc. has been installed in a building located in Seoul. Data collected at an interval of 1 minute are analyzed for studying the energy consumption pattern of a research building. Percentage of energy consumption of all HVAC equipment is $51.0\%$ in 2000, $55.4\%$ in 2001, and $62.3\%$ in 2002, respectively. Electricity consumption of chillers accounts for $17.6\%$ of the total energy consumption, which is the largest. Annual energy consumption-rate per unit area is $840.5Mcal/m^2{\cdot}y$ in 2000, $1,064.8Mcal/m^2{\cdot}y$ in 2001, and $1,393.0Mcal/m^2{\cdot}y$ year 2002, respectively.

• Journal of Trauma and Injury
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• v.32 no.3
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• pp.168-171
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• 2019

The treatment outcome remains poor of severe facial injuries because of the high risk of compromised airway or massive bleeding. We experienced two successful treatment cases of severe facial injury by the chainsaw. A 52-year-male had his face injured by the chainsaw during his work. He was transferred to the Level I trauma center using the Doctor-Helicopter. During his flight, bleeding control was tried and the information was given to the trauma surgeons before his arrival. His consciousness was alert and the vital signs were stable. The crushing wound, mandible open fracture, deep laceration of tongue, lip, neck and arterial bleeding were noted around his mandible. Nasotracheal intubation was performed under the bronchoscope-guided. Emergency operation (open reduction & internal fixation, primary repair with neurorrhaphy) was performed. At 30 hospital days, he was discharged with facial palsy on left mandibular area. A 30-year-male had his face injured by the chainsaw. He was transferred to our Level I trauma center from the local hospital. The deep-mutiple lacerations on right upper eyelid and forehead with the bony exposure were noted. The vital signs were stable and emergency operation was performed. He was discharged at 20 hospital days. Bone loss or tissue loss were not devastating than we expected even though the injury was occurred by the chainsaw. Aggressive treatment including airway manipulation or bleeding control and maximal opportunity of therapy are absolutely needed.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.151-158
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• 2021

The main cause of ulcer is pressure, which starts to develop when the critical body pressure (32mmHg) is exceeded, and when the critical time elapses, ulcer occurs. In this study, the keyboard mechanism of the medical bed with 4 bar links was adopted, and each key can be controlled vertically. A key has one servo drive and one sensor controller which hasseveral body pressure sensors. The sensor controllers and the servo drives are connected to the main controller by two CAN (Car Are Network) in series, respectively. By reading the maximum body pressure value of each keyboard sensor, and by calculating the error value based on the critical body pressure, the fuzzy controller moves each key so that the total error becomes zero. If the fuzzy controller fails, then it prevents ulcer by lifting and lowering the keys of the bed alternatively within a short time. Thus, the controller operates in two-stage. The validity and effectiveness of the proposed approach have been verified through experiments.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.218-227
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• 2021

Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

• The Journal of the Korean Society for Microbiology
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• v.11 no.1
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• pp.69-78
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• 1976

There have been increasing reports of mycobacterioses in man and animals caused by "atypical" or "opportunist" mycobacteria. At the presnt, "opportunist mycobacterioses" are not generally responsive to antituberculosis drugs, and therefore, create considerable problems with regard to chemotherapy and control measures. In recent years studies have been made to isolate opportunist mycobacteria from soil, house-dusts and tap-water. It seemed quite interesting to define the extent of circumstantial presence of "opportunist" mycobacteria and nocardia in the soils of school-ground of primary schools and middle-high schools. This communication is the results of pilot study to isolate and identify "opportunist" mycobacteria and nocardia from 504 soil specimens of 72 schools in Seoul City. 1. Of a total of 59 isolates from 504 soil specimens tested, 32 strains were identified as opportunist mycobacteria and 27 strains as nocardia. 2. Isolation rates of opportunist mycobacteria by the areas(of specimen collection) were as follows: 36.4% in the southern area of Han-River, 33.3% in the central area, 22.7% in the outskirt area and 16.6% in the intermediate area. There observed no apparent difference in the isolation rates both-between the areas and between primary schools and middle-high schools. However, a significant difference was noted in the isolation rates between the places of soil sampling in a given school(P<0.05), i.e., the highest was the soil of refuge heaps(15.2%), and tap-water pole area(11.1%), the school-lavatory entrance(9.7%), the school gate entrance(5.5%), and iron-bar play ground(2.7%). The soil specimens from the center of school ground and from school building entrance yielded none of mycobacterial isolates. 3. Isolation rates of nocardia by the areas were as follows: 33.3% in the central area, 31.8% in the outskirt area, 27.3% in the southern ares of Han-River and 11.1% in the intermediate area. As in the case of mycobacteral isolates, there observed no apparent differences in the isolation rates both between the areas and between primary schools and middle-high schools, but a significant difference was noted between the places of soil sampling(P<0.05), i.e., the highest was the soil of school building entrance(15.2%), and of school gate entrance(6.9%), refuge heaps(5.5,%), iron-bar play ground(4.1%), the school-lavatory entrance(2.7%) and tap-water pole area(2.7%), respectively. The soil specimens from the center of, school ground yielded none of nocardia isolates. 4. Of the 32 strains of isolated mycobacteria. 15 strains were slow-growing mycobacteria and the remaining 17 strains belonged to the rapid growers. Of the 15 slow-growers. 4 strains were M. scrofulaceum-szulgai complex, 3 M. gordonae, 4 M. terrae-triviale complex, 2 M. avium-intracellulare-xenopi complex, and 2 unclassified schotochromogens. Of the 17 strains of rapid growers, 12 were M. diernhoferi, 2 M. fortuitum-peregrinum complex, 2 M. vaccae and one M. flavescens. 5. Of the 27 strains of nocardia isolated, 11 strains were N. transvalensis, 5 N. convoluta, 5 N. erythropolis, one N. vaccinii, one N. polychromogens-paraffinae complex and 4 untypable strains of orange-pigmented nocardia spp.

• BMB Reports
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• v.49 no.5
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• pp.270-275
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• 2016

The Ubiquitin proteasome system (UPS) plays roles in protein degradation, cell cycle control, and growth and inflammatory cell signaling. Dysfunction of UPS in cardiac diseases has been seen in many studies. Cholesterol acts as an inducer of cardiac hypertrophy. In this study, the effect of proteasome inhibitors on the cholesterol-induced hypertrophic growth in H9c2 cells is examined in order to observe whether UPS is involved in cardiac hypertrophy. The treatment of proteasome inhibitors MG132 and Bortezomib markedly reduced cellular surface area and mRNA expression of β-MHC in cholesterol-induced cardiac hypertrophy. In addition, activated AKT and ERK were significantly attenuated by MG132 and Bortezomib in cholesterol-induced cardiac hypertrophy. We demonstrated that cholesterol-induced cardiac hypertrophy was suppressed by proteasome inhibitors. Thus, regulatory mechanism of cholesterol-induced cardiac hypertrophy by proteasome inhibitors may provide a new therapeutic strategy to prevent the progression of heart failure.