Correction to: Engineering Magnetic Type Radio‑Absorbers Based on Composites with a Dual‑Phase Polymer Matrix

Gořalík Marek,Jurča Marek,Bubulinca Constantin,Babayan Vladimír A.,Vilčáková Jarmila,Kazantseva Natalia E.,Sáha Petr 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.5

This work is focused on the optimization of electromagnetic and mechanical properties of magnetic polymer composites for EMI applications as radio absorbers (RAs). Polymer composites with a dual-phase polymer matrix, vinyl-terminated polydimethylsiloxane (PDMS) in epoxy (ER), were investigated for fabricating highlyfilled manganese zinc ferrite (MnZn) and carbonyl iron (CI) composites with respect to radio-absorption and mechanical properties. The dielectric and magnetic properties of the composites were determined by the type, concentration as well as the polymer matrix composition. Increase of the filler and the PDMS concentration leads to an increase in magnetic losses due to a decrease in the demagnetizing field. The electromagnetic properties of the composites were evaluated in the RF band using the impedance method (1 MHz–3 GHz). Based on the complex permittivity (ε*) and the complex permeability (μ*), the reflection loss RL (dB) of single-layer metal-backed RAs were calculated. The RAs with a MnZn ferrite demonstrated a larger bandwidth to thickness ratio in comparison with the CI-based RAs due to a proper ratio between ε* and μ* which leads to the better impedance matching conditions. According to the mechanical analyses (DMA, Charpy impact strength) the significant increase of stiffness up to 125% and the impact strength up to 150% was achieved due to the optimal composition of the polymer matrix and the filler.

炭素纖維板으로 補强한 鐵筋콘크리트보의 構造的擧動에 관한 實驗的 硏究

김하진,고송균,박영배,조창호,김정섭 朝鮮大學校 建設技術硏究所 1998 建設技術硏究 Vol.18 No.1

This study is a part of research to improve the yield strength of concrete structure with a structural damage and conducts the experiment with the variables such as the period of restrengthening of specimen, restrengthening length (1.9m, 1.5m, 1.0m) and restrengthening effect according to restrengthening mehthod of restrengthening materials (nonrestrengthening, Anchor, Angle) to test bending behavior and yield strength performance of reinforced concrete beams restrengthened with carbon fiber laminate. As a result of experiment, in the restrengthening effects by the period of restrengthening, specimen restrengthened before loading, during reloading and after loading show 1.9m, 1.5m and 1.0m respectively, in the restrengthening effects according to restrengthening length, specimen restrengthened with 1.9m, 1.5m and 1.0m show 113.7%, 122.4% and 112.7% and in restrengthening effects according to restrengthening method of restrengthening materials, non-restrengthening and restrengthening in anchor and angle show 113.7%, 115.9% and 184.4% of increase in yield strength respectively. Accordingly, the specimen restrengthened during loading, the specimen with 1.5m of restrengthening and the specimen restrengthened with angle show high restrengthening effects respectively. With the above results, a crack is closed by elastic behavior in the case of test materials, but since in the actual concrete strucutre, a crack is not closed like the specimen during loading, the influence of it on restrengthening should be considered. It is found that although restrengthening effect by the restrengthening length secures a sufficient length, the increase of yield strength by restrengthening cannot be expected when bonded performance is not secured and in deciding restrengthening method of restrengthening materials, the method which have not damage to restrengthening materials and can be integrated with restrengthening materials and structure is effective.

Engineering magnetic type radio-absorbers based on composites with a dual-phase polymer matrix

Marek Gořalík,Marek Jurča,Constantin Bubulinca,Vladimír A. Babayan,Jarmila Vilčáková,Natalia E. Kazantseva,Petr Sáha 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.4

This work is focused on the optimization of electromagnetic and mechanical properties of magnetic polymer composites forEMI applications as radio absorbers (RAs). Polymer composites with a dual-phase polymer matrix, vinyl-terminated polydimethylsiloxane(PDMS) in epoxy (ER), were investigated for fabricating highlyfilled manganese zinc ferrite (MnZn) andcarbonyl iron (CI) composites with respect to radio-absorption and mechanical properties. The dielectric and magnetic propertiesof the composites were determined by the type, concentration as well as the polymer matrix composition. Increase ofthe filler and the PDMS concentration leads to an increase in magnetic losses due to a decrease in the demagnetizing field. Theelectromagnetic properties of the composites were evaluated in the RF band using the impedance method (1 MHz–3 GHz). Based on the complex permittivity (ε*) and the complex permeability (μ*), the reflection loss RL (dB) of single-layer metalbackedRAs were calculated. The RAs with a MnZn ferrite demonstrated a larger bandwidth to thickness ratio in comparisonwith the CI-based RAs due to a proper ratio between ε* and μ* which leads to the better impedance matching conditions. According to the mechanical analyses (DMA, Charpy impact strength) the significant increase of stiffness up to 125% andthe impact strength up to 150% was achieved due to the optimal composition of the polymer matrix and the filler.

Spike Frequency Adaptation in Neurons of the Central Nervous System

Ha, Go Eun,Cheong, Eunji The Korean Society for Brain and Neural Science 2017 Experimental Neurobiology Vol.26 No.4

<P>Neuronal firing patterns and frequencies determine the nature of encoded information of the neurons. Here we discuss the molecular identity and cellular mechanisms of spike-frequency adaptation in central nervous system (CNS) neurons. Calcium-activated potassium (K<SUB>Ca</SUB>) channels such as BK<SUB>Ca</SUB> and SK<SUB>Ca</SUB> channels have long been known to be important mediators of spike adaptation via generation of a large afterhyperpolarization when neurons are hyper-activated. However, it has been shown that a strong hyperpolarization via these K<SUB>Ca</SUB> channels would cease action potential generation rather than reducing the frequency of spike generation. In some types of neurons, the strong hyperpolarization is followed by oscillatory activity in these neurons. Recently, spike-frequency adaptation in thalamocortical (TC) and CA1 hippocampal neurons is shown to be mediated by the Ca<SUP>2+</SUP>-activated Cl- channel (CACC), anoctamin-2 (ANO2). Knockdown of ANO2 in these neurons results in significantly reduced spike-frequency adaptation accompanied by increased number of spikes without shifting the firing mode, which suggests that ANO2 mediates a genuine form of spike adaptation, finely tuning the frequency of spikes in these neurons. Based on the finding of a broad expression of this new class of CACC in the brain, it can be proposed that the ANO2-mediated spike-frequency adaptation may be a general mechanism to control information transmission in the CNS neurons.</P>

실내 환경에서의 트랙터 자동 주차를 위한 카메라 센서 기반의 트레일러 Hitch Joint Angle 검출 알고리즘

장성빈(Sung Been Jang),신희석(Hee seok Shin),김현우(Hyun woo Kim),최윤중(Yoon jung Choi),김정하(Jung Ha Kim) 한국자동차공학회 2022 한국자동차공학회 학술대회 및 전시회 Vol.2022 No.11

Recently, many studies on autonomous vehicles have been conducted, and research on autonomous driving technology has been actively conducted in various fields such as multi-purpose vehicles such as camping cars. In particular, camping cars and large cargo trucks are equipped with trailers on the skin after the vehicle, which are divided into towed trailers and tractors that tow them. The steering angle of the tractor takes precedence over the movement of the trailer because the movement of the tractor and the trailer in the direction of rotation is different when driving backward when parking. Therefore, in order to implement an automatic parking system, we aim to implement an automatic parking algorithm by detecting the angle of the Hitch joint between the tractor and the trailer based on the camera sensor and sending data to determine the steering angle of the tractor.

Deep Learning 기반의 Semantic Segmentation을 활용한 Road Mark 검출

장성빈(Sung Been Jang),정세윤(Se Yun Jung),강동완(Dong Wan Kang),김정하(Jung Ha Kim) 한국자동차공학회 2021 한국자동차공학회 부문종합 학술대회 Vol.2021 No.6

Until recently, research on lane detection and deep learning-based detection algorithms have been actively conducted. When driving straight or changing lanes, the rest of the information except lanes acts as noise, reducing lane recognition accuracy. In particular, the roadmark indicating the direction of progress is similar in colour to the driving lane and thus acts as noise, especially when the vehicle or shadow obscures the triangular area corresponding to the head of the arrow. Therefore, this paper aims to accurately detect road marks by learning and training on Road Mark by using camera sensors to perform deep learning-based Semantic Segmentation.

복합형 다문화가족지원센터의 복합방식 특성과 매개공간 활성화 방안

장하빈(Jang, Ha-Been),권오정(Kwon, Oh-Jung) 한국주거학회 2020 한국주거학회 학술대회논문집 Vol.32 No.2

The study was conducted in Seoul, where the density of multicultural people and many multicultural family support centers are high. Among the centers in question, centers that can be used with other institutions and buildings were defined as compound type multicultural family support centers. And the centers were analyzed in terms of function and space. In addition, a mediated spaces divided by function provided a space for users of the center to interact with users of other facilities. According to the study, the most frequently combined facilities were welfare facilities, education functional facilities, and cultural functional facilities. In the case of a welfare facility, the target of the facility was large in number in the order of the disabled, the entire age, the elderly, children, teenagers, and infants. The spatial complex aspect of the multicultural family support center shows that vertical complex has an overwhelming number of cases. Therefore, in this study, plan was suggested to communicate with the center by proposing mediated spaces and programs that can be created in the outer and inner spaces respectively. In addition, a measure was proposed to increase accessibility for users who have difficulty moving around by installing ramps in the access path.

축냉재 포접화합물의 열물성에 관한 실험적 연구 (IV) : 온도 변화 Changing of Temperature

고광옥,임재경,김창오,김진홍,정낙규,하옥남 조선대학교 에너지.자원신기술연구소 2000 에너지·자원신기술연구소 논문지 Vol.22 No.2

The objective of this paper is to investingate the thermal properties of TMA-clathrate applicable to cold storage system for building air-conditioning in order to use energy reasonably. Especially, the test tube experiments are performed by comparing and to analyzing the temperature of phase change, specific heat and subcooling characteristic according to the variation of concentrations and temperature of heat source in TMA clathrate. The result are summarized as follows; 1) temperature of phase change is dropped as the temperature of heat source is lower 2) specific heat of TMA-clathrate is about 24~95 % of pure-water 3) subcooling is smalled as the temperature of heat source is lower. Thus, it apears that TMA-clathrate has thermal properties as the cold storage medium for residential air-conditioning

Inhibition of Pyruvate Dehydrogenase Kinase 2 Protects Against Hepatic Steatosis Through Modulation of Tricarboxylic Acid Cycle Anaplerosis and Ketogenesis

Go, Younghoon,Jeong, Ji Yun,Jeoung, Nam Ho,Jeon, Jae-Han,Park, Bo-Yoon,Kang, Hyeon-Ji,Ha, Chae-Myeong,Choi, Young-Keun,Lee, Sun Joo,Ham, Hye Jin,Kim, Byung-Gyu,Park, Keun-Gyu,Park, So Young,Lee, Chul- American Diabetes Association 2016 Diabetes Vol.65 No.10

<P>Hepatic steatosis is associated with increased insulin resistance and tricarboxylic acid (TCA) cycle flux, but decreased ketogenesis and pyruvate dehydrogenase complex (PDC) flux. This study examined whether hepatic PDC activation by inhibition of pyruvate dehydrogenase kinase 2 (PDK2) ameliorates these metabolic abnormalities. Wildtype mice fed a high-fat diet exhibited hepatic steatosis, insulin resistance, and increased levels of pyruvate, TCA cycle intermediates, and malonyl-CoA but reduced ketogenesis and PDC activity due to PDK2 induction. Hepatic PDC activation by PDK2 inhibition attenuated hepatic steatosis, improved hepatic insulin sensitivity, reduced hepatic glucose production, increased capacity for beta-oxidation and ketogenesis, and decreased the capacity for lipogenesis. These results were attributed to altered enzymatic capacities and a reduction in TCA anaplerosis that limited the availability of oxaloacetate for the TCA cycle, which promoted ketogenesis. The current study reports that increasing hepatic PDC activity by inhibition of PDK2 ameliorates hepatic steatosis and insulin sensitivity by regulating TCA cycle anaplerosis and ketogenesis. The findings suggest PDK2 is a potential therapeutic target for nonalcoholic fatty liver disease.</P>

Identification of Antihypertensive Peptides Derived from Low Molecular Weight Casein Hydrolysates Generated during Fermentation by Bifidobacterium longum KACC 91563

Ha, Go Eun,Chang, Oun Ki,Jo, Su-Mi,Han, Gi-Sung,Park, Beom-Young,Ham, Jun-Sang,Jeong, Seok-Geun Korean Society for Food Science of Animal Resource 2015 한국축산식품학회지 Vol.35 No.6

Angiotensin-converting enzyme (ACE) inhibitory activity was evaluated for the low-molecular-weight fraction (<3 kDa) obtained from milk fermentation by Bifidobacterium longum KACC91563. The ACE inhibitory activity in this fraction was 62.3%. The peptides generated from the <3 kDa fraction were identified by liquid chromatography-electrospray ionization quantitative time-of-flight mass spectrometry analysis. Of the 28 peptides identified, 11 and 16 were identified as β-casein (CN) and α_s1-CN, respectively. One peptide was identified as κ-CN. Three peptides, YQEPVLGPVRGPFPIIV, QEPVLGPVRGPFPIIV, and GPVRGPFPIIV, from β-CN corresponded to known antihypertensive peptides. We also found 15 peptides that were identified as potential antihypertensive peptides because they included a known antihypertensive peptide fragment. These peptides were as follows: RELEELNVPGEIVE (f1-14), YQEPVLGPVRGPFP (f193-206), EPVLGPVRGPFPIIV (f195-206), PVLGPVRGPFPIIV (f196-206), VLGPVRGPFPIIV (f197-206), and LGPVRGPFPIIV (f198-206) for β-CN; and APSFSDIPNPIGSENSEKTTMPLW (f176-199), SFSDIPNPIGSENSEKT- TMPLW (f178-199), FSDIPNPIGSENSEKTTMPLW (f179-199), SDIPNPIGSENSEKTTMPLW (f180-199), DIPNPIGSENSEKTTMPLW (f181-199), IPNPIGSENSEKTTMPLW (f182-199), PIGSENSEKTTMPLW (f185-199), IGSENSEKTTMPLW (f186-199), and SENSEKTTMPLW (f188-199) for α_s1-CN. From these results, B. longum could be used as a starter culture in combination with other lactic acid bacteria in the dairy industry, and/or these peptides could be used in functional food manufacturing as additives for the development of a product with beneficial effects for human health.