Daeduk University

This study investigates the effectiveness of pre-expanded supraclavicular artery perforator (SAP) and combined with anterior SAP (a-SAP) flap for treating second- and third-degree burn-induced neck scar contractures. We conducted a retrospective observational study of 12 patients with severe second- or third-degree burn-induced neck contractures. All patients underwent an expansion technique in 2 stages. The first stage involved the surgical implantation of 2 tissue expanders: one was positioned above the muscular fascia within the deltopectoral fossa, and the other was above the cervico-acromion region's deep fascia. Upon achieving full expansion, a second-stage surgery was conducted. After complete release and resection of cicatricial neck contractures, the composite flap was then tailored to the wound dimensions and transferred after expander removal. Of the 12 cases, each patient received 2 rectangular tissue expanders ranging from 200 to 350 mL. The average inflation period was 21.1 weeks, resulting in an average total volume of 1244.5 mL. Expanded flap dimensions varied from 17 × 19 cm to 33 cm × 21 cm. In 10 patients, flaps exhibited primary healing with complete survival. Complications included venous congestion (2 case), distal end necrosis of the flap (1 case), subflap hematoma (1 case), all managed with conventional wound care or surgical debridement. The donor site was directly sutured and healed primarily in 9 cases, while a partial-thickness skin graft was used for closure in the remaining 3 cases. During a follow-up period ranging from 3 to 26 months, a significant improvement in range of neck motion was observed, along with satisfactory aesthetic outcomes. Integrating pre-expanded SAP and a-SAP flaps provides a promising reconstructive approach for severe cervical contractures. The proximity of the artery to the neck facilitates direct reconstruction without pedicle division, enhancing aesthetic results through improved skin texture and color matching.

A high-efficiency wireless power transfer-receiver IC that can operate at 2.4 GHz has been proposed. The IC consists of a matching network, rectifier, and DC-DC converter. The rectifier based on the Dickson charge pump topology is designed to have high efficiency by optimizing the number of stages and matching networks. In the proposed IC, a high-efficiency CMOS step-up/step-down DC-DC converter that can operate over a wide input range is involved. The converter provides quadruple conversion ratios of 1/3, 1/2, 2/3, and 2/1, which are determined by the mode selector by sensing the input voltage level. The IC was implemented in a standard 28-nm CMOS process, and post-layout simulation results for the IC demonstrated that the rectifier operates at −8 dBm to 20 dBm and shows a maximum efficiency of 66 % for an input power from −4 to 20 dBm. The DC-DC converter outputs a voltage of 1.6∼2.2 V for a wide input voltage range of 1.2∼5 V and shows a power conversion efficiency of up to 80 %. For the entire IC, the maximum efficiency is 50.8 % at an input power of 12 dBm.

This study sought to analyze the relationship between the operation of volunteer fire brigades and the efficiency of fire-fighting administrations. To this end, the efficiency of the fire-fighting administrations of 16 metropolitan and provincial governments in South Korea were measured using data envelopment analysis (DEA) from 2011 to 2018. In addition, the relationship between the operation efficiency of the volunteer fire brigade and the fire administration was analyzed using a Tobit regression model. DEA found that the technical efficiency based on constant returns to scale was 82.78 ± 18.12%, the technical efficiency based on variable returns to scale was 89.31 ± 12.46%, and the efficiency of the scale was 91.72 ± 10.56%. Tobit regression analysis found the ratio of volunteer fire brigade personnel, the budget ratio of the volunteer fire brigade, and the enforcement of the Act on the Establishment and Operation of Volunteer Fire Brigades to have significant positive effects on the pure technical efficiency of local governments. In addition, when the ratio of volunteer fire brigade personnel or ratio of budget had a positive effect on the efficiency of fire administration, the enforcement of the volunteer fire brigade statute exerted a positive adjustment effect. This study thus shows that volunteer fire brigades have a positive impact on the efficiency of the fire-fighting administrations of metropolitan and provincial governments.

To supply the optimum amount of required power to a load device even when the environmental situations including variation of transfer distance, automated adaptive frequency with power-level tracking systems are proposed based on direct monitoring of the power transfer efficiency (PTE) with received power-level and minimum reflection level observed in the transmitter output via bidirectional out-of-band signalling for efficient and stable mid-range magnetic resonance wireless power transfer (WPT) operations. The effectiveness of the proposed schemes has been successfully demonstrated using a normal digital LED TV, as one of representative exemplary cases. Thus, it is anticipated that the proposed solutions can be commonly useful for any WPT application including mobile devices, electric vehicles, biomedical devices, and many more.

본 논문은 의용소방대의 조직문화가 구성원의 활동만족도에 미치는 영향을 관찰하려는 목적으로 수행되었다. 이를 위해 세종특별자치시라는 범위를 한정하여 의용소방대원 182명을 대상으로 설문을 실시하였다. 조사된 자료는 SPSS 20.0 win 프로그램을 활용하여 설문문항의 신뢰도분석을 실시하였고, 변인들의 빈도분석과 기술통계를 실시하였다. 조직문화의 하위 문화유형인 집단문화, 발전문화, 위계문화, 합리문화가 활동만족도에 미치는 영향을 분석하기 위해 회귀분석을 실시하였다. 집단문화와 위계문화는 유의확률 0.05 이하에서 활동만족도에 긍정적인 영향을 미치는 것으로 나타났다. 의용소방대원이 인식하는 문화유형이 집단문화 그리고 발전문화일수록 의용소방대원의 활동만족도는 높게 나타났다. 이 논문은 우리나라 의용소방대의 효율적 운영을 위한 기초자료로 활용할 수 있을 것으로 기대한다. The purpose of this study is to investigate the influence of organizational culture to the activities satisfaction of volunteer firefighter. For that, we surveyed 182 volunteer firefighters worked in Sejong city. The survey was analyzed the reliability in questionnaire design by SPSS 20.0 win program. The interrelationship of each factors were confirmed by analysis of frequency, percentage and regression analysis. The regression analysis was performed in order to investigate effects of group, development, hierachy, and rationality culture based organizational culture on activities satisfaction of volunteer firefighter. A factor of group and development culture in organizational culture was found to be a positive influence on the activities satisfaction of the volunteer firefighter under significance probability of < 0.05. The bigger group and development culture the volunteer fire department, the higher the activities satisfaction of the volunteer firefighter. This paper is expected to serve as a basis for the efficient operation of the volunteer fire department in Korea.

This paper provides a preliminary study on the piezoresistive effect of a styrene-butadiene Rubber (SBR), one of the main ingredients of automotive tire, dispersed with carbon nanotubes (CNTs) to explore its feasibility as a force sensor embedded in automotive tires. Typically, the application of CNTs has been successfully applied to the mechanical sensing technology such as a stress/strain and impact sensor. In this study, the potential of using the SBR/CNT as a force sensor for monitoring automotive tire deformation is evaluated for the first time. Experimental results show that the electrical resistance of the SBR/CNT composite changes in response to the sinusoidal loading, as well as static compressive load. These piezoresistive responses of the SBR/CNT composite will be used for sensing the tire deformation caused by the vehicle loading or cracks of tires.