• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.87-96
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• 2018

Meteorological information is essential for the safe operation of aircraft. Many organizations both at home and abroad provide meteorological services for small aircraft flying at a low altitude as a part of open public service and have performed relevant studies. Recently, such a service has been expanded to an online platform in order to deliver information more efficiently. The ultimate goal of this study is to improve the meteorological service for small low-altitude aircraft that mostly travel a short distance for a short time. To achieve this goal, this study considered requirements for developing an effective information delivery system and conducted a survey of user requirements to derive the necessary information that could be used to develop a real service.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.571-576
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• 2010

Purpose: Reconstruction of soft tissue defects of the foot often requires free-flap transfer. Free muscle flap transfer and skin grafts on the muscle has been an option for these defects. Here we present our experiences of foot reconstruction using an endoscopy-assisted free muscle flap harvest. Methods: Using endoscopy-assisted free muscle flap harvests, four patients with soft tissue defects of the foot were treated with a free muscle flap and skin graft. The gracilis muscle was used for two patients and the rectus abdominis muscle for two. A single small transverse skin incision was placed on the lower abdomen for the rectus abdominis muscle. A small transverse skin incision on the proximal thigh was the only incision for harvesting the gracilis muscle flap. The small incisions were enough for the muscle flap to be pulled through. Results: The flaps survived successfully in all cases. Contours were good from both functional and aesthetic aspects. No breakdowns or ulcerations of the flap developed during long-term follow-up. Resultant scars were short and relatively hidden. Functional morbidities such as abdominal bulging were not noted. Conclusion: Endoscopy-assisted harvest of muscle flap and transfer with skin graft is a good option for soft tissue defects of the foot. Morbidities of the donor site can be minimized with endoscopic flap harvest. This method is preferable for young patients who want a small donor site scar.

• Clinical and Experimental Pediatrics
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• v.56 no.4
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• pp.176-181
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• 2013

Purpose: Apical muscular ventricular septal defects (MVSDs), especially in small infants, can be difficult to manage using surgical and percutaneous closure. An intraoperative perventricular procedure is a good option for closing apical MVSDs in small children with or without associated cardiac anomalies. We evaluated the results of hybrid perventricular closure of apical MVSDs performed using an Amplatzer duct occluder (ADO). Methods: We retrospectively reviewed the medical records of 5 patients who underwent hybrid perventricular closure of MVSDs with ADOs, from March 2006 to May 2011. The median patient age at the time of the procedure was 12 months (range, 25 days to 25 months), and the median body weight was 9.1 kg (range, 4.3 to 15 kg). Two patients had multiple ventricular septal defects (VSDs; additional perimembranous VSD in 1 patient and multiple MVSDs in the other) and 3 patients had associated cardiac anomalies; complete transposition of the great arteries in 1 patient and an atrial septal defect in 2 patients. All the procedures were performed on beating hearts, exception in 1 case. The ADO selected for the aortic side was at least 1 to 2 mm larger than the largest VSD in the left ventricle side. Results: The procedure was successful in all patients and each device was well positioned. During the median follow-up of 2.4 years, a small residual VSD was noted in 2 patients who had multiple VSDs and no leakage was seen in the other 3 patients. Conclusion: Perventricular closure of MVSD with an ADO is a good option for patients with apical MVSD. However, careful manipulation is important, especially in the case of small infants.

• Journal of Veterinary Science
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• v.23 no.4
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• pp.53.1-53.9
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• 2022

Background: Problems associated with using inhalational anaesthesia are numerous in veterinary anaesthesia practice. Decreasing the amount of used inhalational anaesthetic agents and minimising of cardiorespiratory disorders are the standard goals of anaesthetists. Objective: This experimental study was carried out to investigate the sparing effect of intravenous tramadol, lidocaine, dexmedetomidine and their combinations on the minimum alveolar concentration (MAC) of sevoflurane in healthy Beagle dogs. Methods: This study was conducted on six beagle dogs. Sevoflurane MAC was determined by the tail clamp method on five separate occasions. The dogs received no treatment (control; CONT), tramadol (TRM: 1.5 mg kg^-1 intravenously followed by 1.3 mg kg^-1 h^-1), lidocaine (LID: 2 mg kg^-1 intravenously followed by 3 mg kg^-1 h^-1), dexmedetomidine (DEX: 2 ㎍ kg^-1 intravenously followed by 2 ㎍ kg^-1 h^-1), and their combination (COMB), respectively. Cardiorespiratory variables were recorded every five minutes and immediately before the application of a noxious stimulus. Results: The COMB treatment had the greatest sevoflurane MAC-sparing effect (67.4 ± 13.9%) compared with the other treatments (5.1 ± 25.3, 12.7 ± 14.3, and 40.3 ± 15.1% for TRM, LID, and DEX treatment, respectively). The cardiopulmonary variables remained within the clinically acceptable range following COMB treatment, although the mean arterial pressure was higher and accompanied by bradycardia. Conclusions: Tramadol-lidocaine-dexmedetomidine co-infusion produced a remarkable sevoflurane MAC-sparing effect in clinically healthy beagle dogs and could result in the alleviation of cardiorespiratory depression caused by sevoflurane. Cardiorespiratory variables should be monitored carefully to avoid undesirable side effects induced by dexmedetomidine.

• Agribusiness and Information Management
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• v.3 no.2
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• pp.9-16
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• 2011

With the confirmation of the Free Trade Agreement (FTA) and as cheap foreign agricultural products are beginning to be freely distributed in Korea, the government has taken a greater interest in securing the competitiveness of domestic agriculture. Accordingly, the Korean government has presented plans to advance the interests of 'small but strong farmers' and secure their competitiveness in line with the agricultural conditions in Korea. The government also announced that it will focus on leading these efforts in rural areas. The main thrust of this plan to support 'small but strong farmers' focuses onutilizing advanced peripheral technologies such as IT and BT; however, there are only a few Information Management Division centers currentlyoperating across the nation, and these are mainly in the IT-related divisions of the Agricultural Research and Extension Services and Agricultural Technology Centers. Therefore, in this study, we used the responses from a survey of farmers to identify regional differences in informatization levels and the digital divide among 'small but strong farmers' according to the presence or absence of an Information Management Division center. As a result, we found that the 'small but strong farmers' in regions with an active Information Management Division center received more IT services and had a higher level of informatization. Thus, to increase the use of IT-related peripheral technology by these 'small but strong farmers', it is important to maintain or increase the number of Information Management Division centers.

• Journal of Power Electronics
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• v.16 no.3
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• pp.849-860
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• 2016

The high-switching-frequency operation of power converters can achieve high power density through size reduction of passive components, such as capacitors, inductors, and transformers. However, a small-output capacitor that has small capacitance and low effective series resistance changes the small-signal model of the converter power stage. Such a capacitor can make the converter unstable by increasing the crossover frequency in the transfer function of the small-signal model. In this paper, the design and implementation of a high-frequency LLC resonant converter are presented to verify the power density enhancement achieved by decreasing the size of passive components. The effect of small output capacitance is analyzed for stability by using a proper small-signal model of the LLC resonant converter. Finally, proper design methods of a feedback compensator are proposed to obtain a sufficient phase margin in the Bode plot of the loop gain of the converter for stable operation at 500 kHz switching frequency. A theoretical approach using MATLAB, a simulation approach using PSIM, and experimental results are presented to show the validity of the proposed analysis and design methods with 100 and 500 kHz prototype converters.

• Korean Journal of Remote Sensing
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• v.24 no.5
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• pp.507-515
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• 2008

Many studies have generally used a large number of pure pixels as an approach to training set design. The training set are used, however, varies between classifiers. In the recent research, it was reported that small mixed pixels between classes are actually more useful than larger pure pixels of each class in Support Vector Machine (SVM) classification. We evaluated a usability of small mixed pixels as a training set for the classification of high-resolution satellite imagery. We presented an advanced approach to obtain a mixed pixel readily, and evaluated the appropriateness with the land cover classification from IKONOS satellite imagery. The results showed that the accuracy of the classification based on small mixed pixels is nearly identical to the accuracy of the classification based on large pure pixels. However, it also showed a limitation that small mixed pixels used may provide insufficient information to separate the classes. Small mixed pixels of the class border region provide cost-effective training sets, but its use with other pixels must be considered in use of high-resolution satellite imagery or relatively complex land cover situations.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.91-102
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• 2020

Recently, a new space era has evolved in which commercial companies' led space development has begun. In this era, commercial companies actively participate in space development as the size of the small satellite market and small launch vehicle market is expanding. Through space development, developed countries are making efforts to reduce development, production, and operation costs to secure the competitiveness of small launch vehicles. In this study, the development trend of small launch vehicles and required technologies for space development were analyzed and summarized. Thus, research and development is urgently needed so that spin-on technologies, such as electric pumps and additive manufacturing, can be utilized for space development.

• Korean Journal of Materials Research
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• v.33 no.6
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• pp.236-241
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• 2023

Solar cells based on p-conjugated donor-acceptor (D-A) organic molecular systems are a promising alternative to conventional electrical energy generation. D-A molecular systems, which have a triphenylamine (TPA) moiety linked with a benzothiadiazole (BTD) moiety, open the potential development of new small molecule donors for bulk heterojunction (BHJ) solar cells. Here, a series of donor-acceptor-π-acceptor (D-A-π-A) small molecule donors (SMD) derived from triphenylamine (TPA) donor and benzothiadiazole (BTD) acceptor building blocks, were designed for BHJ organic solar cells. The small molecule donors SMD1-4 were studied using density functional theory (DFT) and time dependent-DFT (TDDFT) methods, to understand the effect of cyano and fluorine group functionalization on their properties. The effect of structure alteration by cyano and fluorine group functionalization on the optoelectronic properties, the calculated highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) and the HOMO-LUMO gaps were theoretically explored. The V_oc (open-circuit photovoltage) and fill factor (FF) for SMD1-4 were obtained with a PC₇₁BM acceptor, which showed that these organic small molecules are potential small molecule donors for organic bulk heterojunction solar cells.

• The Research Journal of the Costume Culture
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• v.24 no.3
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• pp.315-323
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• 2016

The present study is intended to study sole types necessary for shoe designs for elementary school students that are in age groups in growth periods, and 3D midsole design utilizing 3D printing technology. This study analyzed data from the 3D measurement of the feet of 1,227 elementary school students aged 7-13 years residing in the capital region conducted as part of the 6th Anthropometry of Size Korea. In addition, 3D midsoles by sole type were designed utilizing a Rhino CAD, and midsole prototypes were output utilizing a Zortrax-M200 3D Printer. Through a cluster analysis of sole shapes by type, sole shapes were classified into three types. Type 1 has small values of foot lengths and foot breadths, with large toe 1 angles and high arch heights. Type 2 has intermediate values of foot lengths and foot breadths, with small toe 1 angles and high arch heights. Type 3 has large values of foot lengths and foot breadths with small toe 1 angles and low arch heights. On reviewing the results of design of 3D midsoles by sole type, it can be seen that the midsoles were designed according to characteristics by sole type. The results of the sole type analysis in the present study are expected to be meaningful as basic data for the development of shoe insoles for elementary school students.