When the CP voltage is disconnected, the measured voltage on the ICCB side is measured to be 12V, and the voltage on the OBC side is measured to be 0V. When the PD signal was disconnected, the ICCB-side measured voltage was 0V and the OBC-side measured voltage was 4.5V. From this, disconnected position be found with the voltage value measured. When CP was disconnected for a short time, the PD voltage did not change to 1.5V, and when the PD was disconnected, the CP signal and PD signal changed to 9V, and if the CP and PD voltages were normal, the charge control could be performed normally.

국제해사기구에서는 선박에서 배출되는 질소산화물 및 이산화탄소 등에 관한 환경규제를 꾸준하게 강화하고 있다. 이에 친환 경 요소를 바탕으로 하는 전기추진시스템의 수요가 증가하고 다양한 선박에 적용되며 연구개발이 꾸준하게 진행되고 있다. 전기추진시스 템은 신뢰성을 높이고 선내 배치를 용이하게 하기 위한 이중화 구성이 주로 채택되며 실제 장비나 공간을 가상 세계에 쌍둥이처럼 구현 하고 현실 세계의 정보와 데이터를 가상 세계와 통합하여 실제 환경에서 발생할 수 있는 상황을 컴퓨터로 시뮬레이션 함으로써 결과를 미리 예측할 수 있는 디지털트윈 기술의 접목을 통하여 전기추진시스템의 안전성 확보를 위한 연구 또한 매우 활발하게 진행되고 있다. 본 연구에서는 전기추진선박의 디지털트윈 기술개발을 위한 전력관리시스템 이중화에 대한 검증을 FMEA를 바탕으로 분석 후 선급에서 제시하는 이중화 FMEA 기준을 바탕으로 실제 선박 운항 조건에서 전력관리시스템의 단일 장비 고장의 일차 피해와 이차 피해 및 전체 시스템의 영향을 분석하여 추가 피해를 방지하기 위한 보상기능으로 전력관리시스템의 역할과 알고리즘을 제안하였으며 실제 테스트를 통해 추진력 보존이 개선되었음을 검증하였다.

목적 : 본 연구는 여가 및 사회참여를 위해 수 ․ 전동휠체어를 사용해본 휠체어 사용 장애인들을 대상으로 포커스그룹인터뷰를 수행하여 사용자 경험을 파악하고, 수 ․ 전동휠체어 개발 시 고려해야 할 요소와 임상가의 수 ․ 전동휠체어 처방을 위한 기초자료를 제시하고자 한다. 연구방법 : 본 연구는 수ㆍ전동휠체어를 사용해본 휠체어 사용 장애인 5명을 대상으로 정성적 연구방법인 포커스그룹인터뷰를 실시하였다. 질문은 Krueger와 Casey가 제시한 질문방식을 기반으로 하였으며, 현장메모, 녹음된 자료를 3명의 저자가 독립적으로 전사하여 Braun과 Clarke’s가 제시한 절차에 따라 분석하였다. 결과 : 참여자들은 수ㆍ전동휠체어를 사용하여 지역사회 내에서 직업, 여가 그리고 해외 활동 등 다양한 활동을 수행하고 있으며, 수ㆍ전동휠체어는 전동휠체어와 비교하여 무게가 가볍고, 크기가 작아 차량 탑재 시 용이하기 때문에 선택되었다. 하지만 휠체어 사용자들은 휠체어의 추진 구조물, 지지 구조물 그리고 소재 등에 문제점을 보고하였다. 참여자들은 경험한 수ㆍ전동휠체어의 문제점 개선과 함께 외형 디자인의 개선을 기대했고, 추가적으로 안전한 주행을 위해 가슴벨트나 넘어짐 방지 바퀴와 같은 부속품을 포함해야 한다는 의견도 있었다. 이처럼 적극적인 여가참여를 수행하기 위해 수ㆍ전동휠체어의 안전성에 대한 의견이 특히 강조되었다. 결론 : 본 연구는 여가 및 사회참여 활동 시 수ㆍ전동휠체어 사용자의 경험을 임상가 관점에서 파악하였 다. 향후 노인 및 휠체어 장애인을 위한 수ㆍ전동휠체어 개발 시 고려사항과 휠체어 사용자 평가 및 휠 체어 처방 시 임상가가 고려해야할 점을 제시하였으며, 실효성 높은 보조기기 개발을 위한 기초자료로 활용되길 기대한다.

The purpose of this study is to reduce the probability of occurrence of electric fires as a preemptive preventive measure, and to strengthen the capability of preventing electric fires by strengthening the cooperative function between electric fire-related departments and establishing a cooperative system. In this study, the general aspects of electric fires were identified by reviewing the literature such as ignition mechanisms of electric fires. And the major electrical fires that occurred in the last 10 years were classified into ignition factors (short circuit, overload/overcurrent, and earth leakage/ground fault) and ignition sources (wiring/wiring appliances, electrical equipment/household appliances). And the 4M technique was used to analyze the potential causes of ignition at the fire site and to suggest preventive measures. In the case In this study, out of 48 electrical fires in the past 10 years, 16 short-circuit fires, 3 overload/ overcurrent fires, 3 short-circuit and earth fault fires, 16 fires in wiring/wiring appliances, and 10 fires in electrical equipment/home appliances classified as cases. And prevention measures were presented in terms of human, machine, media, and management by using the 4M technique. For the preemptive prevention of electric fires, strengthening the compulsory electrical safety inspection and making it mandatory to report when new or expanding electric facilities, charging a fee for electric safety inspection for detached houses and granting benefits subject to inspection completion, improvement of the electric safety voluntary inspection table and safety indications; It was suggested as a policy to organize and operate electrical safety inspection personnel in a two-person team (mixed), establish a close work cooperation system with related organizations, and strengthen electrical safety education and publicity.

As the use of capacitors in electrical appliances and electrical control circuits increases, the related electrical fire is increasing. There are various parts such as resistors, coils, and capacitors that make up an electric circuit. Among them, the ignition of a capacitor with a temporary charging function is closely related to the structural characteristics of the capacitor. Capacitors can explode due to various reasons, and the high heat generated when they explode ignites the inflammable dielectric, which in turn burns the inflammable materials such as the surrounding electric wires and spreads into a fire. In this paper, the ignition mechanism is studied by conducting a reenactment experiment on the various probabilities that can be ignited in an electric capacitor, and the prevention measures to be applied to the fire prevention are presented.

육상 및 해상에서의 화재 사고는 심각한 인명피해를 발생시키며 특히 해양 플랜트 및 선박의 특성 상 밀폐공간으로 인한 질식 사고 사망률이 육상보다 현저히 높다. 이러한 질식사고를 예방하기 위하여 화재에서 발생하는 유독가스를 외부로 배출할 수 있는 환기용 팬의 설치가 필수적이나, 해양화재의 규모를 고려하였을 때 대형 환기용 팬의 설치는 해양 구조물 특성상 용이하지 않다. 따라서 본 연구 에서는 DC 전기장을 인가하여 화재 유독가스를 제어하는 새로운 개념의 소방기술을 개발하고자 한다. 화재 발생 시 대부분의 화염은 화학 이온화로 인해 양전하와 음전하를 다수 함유하고 있고, 이때 전기장을 인가하게 되면 로렌츠 힘에 의해 “이온풍”이 발생하게 된다. 이러한 이온풍을 활용하여 일반건축물과 선박의 단열재로 많이 사용되는 종이와 스티로폼을 연소하여 발생되는 화재연기를 인위적으로 제어하는 실험적 연구를 수행하였다. 실험 결과, ± 5 kV 이상의 직류전압을 인가하였을 때 화재연기를 인위적으로 제어할 수 있었고, 양전압 보다 음전압을 인가하였을 때 상대적으로 효과적인 제어가 가능하였다.

It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

바쁜 일상 속에서 신체 활동량의 감소와 식생활의 서구화 등으로 인한 복부 비만의 발생률이 높아지고 있다. 따라서 체형 관리에 대한 욕구를 충족시키기 위해 시간 대비 고 효율의 관리 프로그램이 필요하다. 본 연구에서는 전기근육자극요법 (electric muscle stimulation therapy)을 활용하여 다이어트젤 (슬리밍 화장품)과의 복합사용에 의하여 허리둘레 및 체지방량 (또는 복부의 지방)를 감소 효과를 촉진시켰다. 연구 대상자는 20대 성인 남녀로 다이어트젤을 허리 부위에 단순 도포를 한 후, 그 위에 EMS를 착용 하여 기상 후와 취침 전에 1일 2회 20분간 마사지를 실시하였다. 실험 기간은 2주 동안 실시되었다. 지방 분해 촉진 효과는 비 조영 CT를 활용하여 피하지방의 감소에 대한 관찰이 되었으며, 이와 함께 허리둘레와 체지방량 측정으로 확인되었다. 결론적으로 개발된 EMS와 다이어트젤의 동시 사용 프로그램은 약 3 cm (p<.001)의 허리둘레 감소와 약 1 kg (p<.01)의 체지방량 감소를 나타내어 허리라인 관리에 탁월한 효과가 있음을 입증하였다. 이는 EMS의 활용이 근육 자극에 의한 마사지 효과를 나타내며 다이어트젤의 흡수를 도와 지방 분해를 촉진시키는 역할을 하는 것으로 사료된다.

Owing to its low cost, easy fabrication process, and good ionic properties, aqueous supercapacitors are under strong consideration as next-generation energy storage devices. However, the limitation of the current collector is its poor electrochemical stability, leading to low energy storage performance. Therefore, a reasonable design of the current collector and the acidic electrolyte is a necessary, as well as interfacial engineering to enhance the electrochemical performance. In the present study, graphite foil, with excellent electrochemical stability and good electrical properties, is suggested as a current collector of aqueous supercapacitors. This strategy results in excellent electrochemical performance, including a high specific capacitance of 215 F g−1 at a current density of 0.1 A g−1, a superior high-rate performance (104 F g−1 at a current density of 20.0 A g−1), and a remarkable cycling stability of 98 % at a current density of 10.0 A g−1 after 9,000 cycles. The superior energy storage performance is mainly ascribed to the improved ionic diffusion ability during cycling.

High voltage impulse (HVI) has been gained attention as an alternative technique that could control the CaCO3 scale problems encountered in water main, pipe, cooling tower and heat exchanger vessels. The aim of this study was to investigate the effect of electric field (E) and contact time (t) of HVI on reduction of Ca2+ concentration at two different temperatures of 25℃ and 60℃. A kinetic model on the effect of E and t was investigated too. As the E and t increased, the Ca2+ concentration decreased more than that of the control (= no HVI). The Ca2+ concentration decreased up to 81% at 15 kV/cm at 60℃, which was nearly 2 times greater than the control. With these experimental data-set of reduction of Ca2+ concentration under different E and t, the kinetic model was developed. The relationship between E and t required to reduce the concentration of Ca2+ by 30% was modeled at each temperature. The empirical model equations were; E0.83· t = 60.3 at 25℃ and E0.08· t = 1.1 at 60℃. These equations state the products of En and t is always constant, which means that the required contact time can be reduced in accordance with the increment of E and vice versa.

Engineering the microstructure of the carbonaceous materials is a promising strategy to enhance the capacitive performance of supercapacitors. In this work, nanostructured Black Pearl (1500 BP) carbon which is a conductive carbon being commercially used in printing rolls, conductive packaging, conductive paints, etc. is analyzed for its feasibility as an electrode material for Electric Double-Layer Capacitors (EDLCs). To achieve that commercial Black Pearl (BP), carbon is treated with mild acid H3PO4 to remove the impurities and enhance the active sites by regulating the growth of agglomerates and creating micropores in the nano-pigments. Generally, the coalescence of nanoparticles owing to their intrinsic surface energy has tendency to create voids of different sizes that act like meso/micropores facilitating the diffusion of ions. The electrochemical performance of BP carbon before and after chemical activation is investigated in aqueous ( H2SO4, KOH and KCl) and a non-aqueous electrolyte (1 M TEMABF4 in acetonitrile) environment employing different electrochemical techniques such as Cyclic Voltammetry (CV), Galvanostatic charge/discharge (GCD) and Electrochemical Impendence Spectroscopy (EIS). The chemically activated BP carbon delivers the highest specific capacitance of ∼156 F g−1 in an aqueous electrolyte, 6 M KOH. The highest specific power, ~ 15.3 kW kg−1 and specific energy, 14.6 Wh kg−1 are obtained with a symmetric capacitor employing non-aqueous electrolyte because of its high working potential, 2.5 V.

In this study, we developed a facile and template-free strategy for the preparation of activated porous carbon beads (APCBs) from polyacrylonitrile. The chemical activation with KOH was found to enhance the pore properties, such as specific surface area (SSA), pore volume, and pore area. The APCBs exhibited a large SSA of 1147.99 m2/g and a pore area of 131.73 m2/g. The APCB-based electrodes showed a good specific capacitance of 112 F/g at 1 A/g in a 6 M KOH electrolyte, and excellent capacitance retention of 100% at a current density of 5 A/g after 1000 cycles. Therefore, the APCBs prepared in this study can be applied as electrode materials for electric double-layer capacitors.

본 연구는 선박용 공기압축기의 상태기반보전 시스템에 필요한 이상치 탐지 알고리즘 적용에 대한 실험적 연구로서 고장모사 실험을 통해 시계열 전류 센서 데이터를 이용한 이상탐지 적용 가능성을 확인하였다. 고장 유형 10개에 대해 실험실 규모의 고장 모사 실험을 수행하여 정상 운전데이터와 고장 데이터를 구축하였다. 실험 결과 구축된 이상탐지 모델은 시계열 데이터의 주기에 변화를 유발하는 이상은 잘 탐지하는 반면 미세한 부하 변동에 대한 탐지 성능은 떨어졌다. 또한 오토인코더를 이용한 시계열 이상탐지 모델은 입력 시 퀀스의 길이와 초모수 조정에 따라 이상 탐지 성능이 상이한 것으로 나타났다.

In this study, the models with types A, B and C of the commercial electric kickboard suspensions were modeled and the structural analyses were carried out. Types A and C have the deformations less than type B. The coil spring can reduce the deformation by installing the suspension. In types A and C, the forces applied to the bolt became same, but more deformation occurred in type C. This is the difference due to whether or not there is a fixed part. Type A was fixed and type C not. This fixation indicates that the bolt has been fully tightened to the end. Therefore, the use of products thatarefully contacted to the end by tightening with bolts can reduce the deformation greatly. Based on the data obtained from this study, it is assumed that the more efficient and stable product will be designed if the suspension absorber of the suspension is designed. Without the test on the durability of electric kickboard suspension, the durability can be seen as the deformation and stress are investigated through the structural analysis.

We report the structural characterization and electric heating performance of carbon thin films (CTFs), which were prepared from negative-type SU-8 photoresist by deep UV exposure and following carbonization. The prepared CTFs were found to have pseudo-graphitic carbon structures containing partially graphite domains in the amorphous carbon matrix. The CTFs showed a very smooth surface morphology with a roughness of 0.42 nm. The 107 nm-thick CTFs exhibited an excellent electric heating performance by attaining a high maximal temperature of 207 °C and a rapid heating rate of 13.2 °C/s at an applied voltage of 30 V. Therefore, the CTFs prepared in this study can be applied as electrode materials for high-performance electric heaters.

Currently, domestic seaweed production is about 800,000 tons per year, which is the largest seaweed production in the world after China and Japan. However, most seaweeds (Pyropia ssp, Undaria pinnatifida, Saccharina japonica, etc) are consumed in the form of dried products or hot water extracts, and there are many difficulties in developing various products due to difficulties in the manufacturing process. Through the pulsed electric field treatment device, the extraction efficiency can be expected to increase compared to the convectional hot water extraction. Pulsed electric field technology is a non-heating treatment technology in which high-voltage electric energy is processed into cells in the form of pulses, affecting the potential difference of cell membranes, and performing collapse or perforation treatment. In this study, components such as protein and carbohydrate content were extracted by treating Saccharina japonica with PEF, and compared with the hot water extraction method, As a result of experiment at voltages of 0.7 and 1.5㎸ and pulse duration of 5㎲, the crude protein content increased by up to 42% and the sugar content increased by up to 30% compare to the hot water extraction. Higher efficiency results can be expected through optimization of several parameters that may affect the extraction process.