Post-Occupancy Evaluation of One-room Apartment in Seoul, Korea to Enhance Occupant Comfort and Satisfaction – Focused on Studio Residential Properties for University Students

Deng, Yuan-fei(등원비),Park, Jihyun(박지현) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.2

The proportion of single households in Korea has now risen dramatically to become the most common household type in the country. Because of the rapid progress of urbanization, the population density and building density of Seoul have risen dramatically, but because of this, many buildings in the city do not have a good indoor environment. The purpose of this study is to investigate the living comfort of studio rooms in which university students live in Seoul, to understand the strengths and weaknesses of their indoor environmental quality, and to provide guidance for improving their environmental quality. Because it is relatively good price and guarantees privacy, studio is the first choice for single-person households, especially for the university student population. Based on our assessment results, overall, university students currently living in studios in Seoul need more natural light, better ventilation, and quieter living environments than the status quo, which will require not only a reduction in building density and a widening of the distances between buildings in future development activities, but also more careful consideration of ventilation, heat and thermal insulation, and soundproofing in the design.

Design and Stability Analysis of Buck-Boost Converter Applied with Adaptive Voltage Positioning Technique

Fei Deng,Guangjun Xie,Xin Cheng 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.7

Identification of novel rheumatoid arthritis-associated MiRNA-204-5p from plasma exosomes

Wu Long-Fei,Zhang Qin,Mo Xing-Bo,Lin Jun,Wu Yang-Lin,Lu Xin,He Pei,Wu Jian,Guo Yu-Fan,Wang Ming-Jun,Ren Wen-Yan,Deng Hong-Wen,Lei Shu-Feng,Deng Fei-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Rheumatoid arthritis (RA) is an autoimmune disease characterized by infiltration of immune cells in the synovium. However, the crosstalk of immune cells and synovial fibroblasts is still largely unknown. Here, global miRNA screening in plasma exosomes was carried out with a custom microarray (RA patients vs. healthy controls = 9:9). A total of 14 exosomal miRNAs were abnormally expressed in the RA patients. Then, downregulated expression of exosomal miR-204-5p was confirmed in both the replication (RA patients vs. healthy controls = 30:30) and validation groups (RA patients vs. healthy controls = 56:60). Similar to the findings obtained in humans, a decreased abundance of exosomal miR-204-5p was observed in mice with collagen-induced arthritis (CIA). Furthermore, Spearman correlation analysis indicated that plasma exosomal miR-204-5p expression was inversely correlated with disease parameters of RA patients, such as rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein. In vitro, our data showed that human T lymphocytes released exosomes containing large amounts of miR-204-5p, which can be transferred into synovial fibroblasts, inhibiting cell proliferation. Overexpression of miR-204-5p in synovial fibroblasts suppressed synovial fibroblast activation by targeting genes related to cell proliferation and invasion. In vivo assays found that administration of lentiviruses expressing miR-204-5p markedly alleviated the disease progression of the mice with CIA. Collectively, this study identified a novel RA-associated plasma exosomal miRNA-204-5p that mediates the communication between immune cells and synovial fibroblasts and can be used as a potential biomarker for RA diagnosis and treatment.

Neutronic design and evaluation of the solid microencapsulated fuel in LWR

Deng Qianliang,Li Songyang,Wang Dingqu,Liu Zhihong,Xie Fei,Zhao Jing,Liang Jingang,Jiang Yueyuan 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.8

Solid Microencapsulated Fuel (SMF) is a type of solid fuel rod design that disperses TRISO coated fuel particles directly into a kind of matrix. SMF is expected to provide improved performance because of the elimination of cladding tube and associated failure mechanisms. This study focused on the neutronics and some of the fuel cycle characteristics of SMF by using OpenMC. Two kinds of SMFs have been designed and evaluated - fuel particles dispersed into a silicon carbide matrix and fuel particles dispersed into a zirconium matrix. A 7x7 fuel assembly with increased rod diameter transformed from the standard NHR200-II 9x9 array was also introduced to increase the heavy metal inventory. A preliminary study of two kinds of burnable poisons (Erbia & Gadolinia) in two forms (BISO and QUADRISO particles) was also included. This study found that SMF requires about 12% enriched UN TRISO particles to match the cycle length of standard fuel when loaded in NHR200-II, which is about 7% for SMF with increased rod diameter. Feedback coefficients are less negative through the life of SMF than the reference. And it is estimated that the average center temperature of fuel kernel at fuel rod centerline is about 60 K below that of reference in this paper

Ultrafast dynamics control on ablation of Cu using shaped femtosecond pulse trains

Deng Jiannan,Qi Hongxia,Liu Xinyi,Li Xiaoyi,Tong Qiunan,Lian Zhenzhong,Li Juan,Bo Jinqiu,Fei Dehou,Chen Zhou,Hu Zhan 한국물리학회 2021 Current Applied Physics Vol.26 No.-

The ablation processes of Cu film are investigated using temporal shaped femtosecond pulse trains. The depth is modulated by changing the number and interval of the sub-pulses. The underlying ultrafast dynamic processes are discussed based on plasma shielding and electron multiple heating mechanisms. When the sub-pulse interval is less than 0.4 ps electron multiple heating is the dominant mechanism, while the plasma shielding dominates the subsequent ablation processes when the sub-pulse interval is larger than 0.4 ps. The curve of depth obtained by three pulse trains shows more significant oscillation as the function of sub-pulse interval under the lowfluence. We propose that the oscillation of depth is due to the coherent phonon oscillation excited by the pulse train. The study provides a basis for giving insight into the ultrafast dynamics for improving micromachining and nano-fabrications using shaped femtosecond pulse trains.

A novel water-cooling magnetorheological transmission device

Fei Chen,Xiao Wang,Haopeng Li,Aimin Li,Yongrui Deng,Zuzhi Tian,Xiangfan Wu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

Magnetorheological (MR) fluid in power transmission devices, especially in highpower transmission devices, sometimes works at high temperatures owing to wall slip, particle friction, and exciting current. In such cases, effective heat dissipation is crucial. A novel watercooling structure is proposed to deal with the negative effect of centrifugal force on heat dissipation. The magnetic circuit of the novel MR transmission device is designed on the basis of electromagnetic theory, and the magnetic field is investigated by finite element calculation. Experiments under extreme condition show that the temperature of MR fluid in the device drops sharply from 70 °C to 28 °C, and the heat generated inside the device dissipates instantly. Results show that the novel power transmission device has excellent heat dissipation effect.

Experimental investigation of masonry walls supported by steel plate-masonry composite beams

Deng-Hu Jing,Jian-Fei Chen,Giuseppina Amato,Ting Wu,Shuang-Yin Cao 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.6

Masonry walls are sometimes removed in buildings to either make new passages or increase the usable space. This may change the loading paths in the structure, and require new beams to transfer the loads which are carried by the masonry walls that are to be removed. One possible method of creating such new beams is to attach steel plates onto part of the existing walls to form a steel plate-masonry composite (SPMC) beam, leading to a new structure with part of the masonry wall supported by a new SPMC beam. This paper presents an experimental investigation into the interaction between the SPMC beam and the masonry wall above. Five SPMC beams supporting a masonry wall were tested to study the influence of parameters including the height-to-span ratio of the masonry wall, height of the beam and thickness of the steel plates. The test results, including failure mode, load-carrying capacity, load-deflection curves and strain distribution, are presented and discussed. It is found that for developing better arching effect in the masonry wall the ratio of the in-plane flexural stiffness of the masonry wall to the flexural stiffness of the SPMC beam must be between 2.8 and 7.1.

2D-2D heterostructured composites Bi4O5Br2-SnS2 with boosted photocatalytic NOx abatement

Fei Chang,Zhixun Wei,Zhongyuan Zhao,Yingfei Qi,Deng-guo Liu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

A desirable photocatalytic system ought to feature efficient NOx removal and retardance of toxic NO2 generation. In this investigation, a series of novel two-denominational (2D)-2D composites Bi4O5Br2-SnS2 (XBS) were successfully fabricated through a simple mechanical ball-milling route and characterized systematically. The coexistence of both expected components was confirmed. 2D morphologies of both componentswere stacked in face-to-face manner and thus formed heterojunction structures, verified by SEMand TEM patterns. The visible-light absorption was enhanced in composites caused by the shrinkage ofband gaps. With microstructural and optical merits, these binary composites showed reinforced photocatalyticabatement of NOx and attenuated generation of toxic NO2 under visible light, compared withbare Bi4O5Br2. Successive recycling catalytic experiments revealed the satisfactory reusability and structuralstability of achieved composites. Ultimately, a reasonable type-II model was deduced to describe themigration and transfer of interface carriers based on experimental and analytical results. Such workdesigned and provided various bismuth-based composites constructed by the simple mechanical ballmillingfor controlling and treating nitrogen oxides at ppb level in the atmospheric environment.

An Extended Switched-inductor Quasi-Z-source Inverter

Deng, Kai,Mei, Fei,Mei, Jun,Zheng, Jianyong,Fu, Guangxu The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

In this paper, an extended switched-inductor quasi-Z-source inverter (ESL-qZSI) with high boost voltage inversion ability is presented, which combines the SL-qZSI with the traditional boost converter, as well as improves the switched-inductor cell. Compared with the classic qZSI topologies, the proposed topology reduces the voltage stresses of capacitors, power devices and diodes for the same input and output voltage. Furthermore, the conversion efficiency is improved. The operation principle of the proposed topology is analyzed in details, which is followed by the comparison between the three topologies. In addition, the performance of the proposed topology is verified by simulations and experiments.

Shunt Active Power Filter Based on a Novel Sliding Mode Backstepping Control for Three-phase Three-wire System

Lihua Deng,Juntao Fei,Changchun Cai 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper presents a global fast terminal sliding mode (GFTSM) control based on backstepping design for active power filter(APF). Power system is a typical nonlinear system. Its mathematic model can be reduced order by backstepping method. Power system is decomposed into low-level subsystems until finalizing the design of the control law. The System’s stability is ensured by Lyapunov framework. The sliding mode control is added into backstepping control to expand the application scope of control. The sliding mode control doesn’t need accurate model of system. Therefore robustness of APF control is improved. Global fast terminal control is added into sliding mode control. The nonlinear term of GFTSM control makes the system converge quickly when far from equilibrium point, and the linear term do when near equilibrium point. It makes the system’s state tracking error reach zero in finite time. The control speed of system is enhanced. An experiment based on MATLAB/SIMULINK is designed to compare GFTSM backstepping control with pure backstepping control, and experimental results confirm the validity of proposed APF controller for a three-phase three-wire system.