Modal Analysis of a Single-Aperture Monopulse Feed Horn

Ren Chun,Ding Zhiyoung,Ki-Rock Kim,Ononchimeg Sodnomtseren,Bierng-Chearl Ahn 한국정보기술학회 2008 한국정보기술학회논문지 Vol.6 No.6

In this paper, we present a modal analysis of a single-aperture monopulse feed horn. The horn aperture is of square type and it is assumed that necessary higher-order modes can be generated by suitable means. First we consider the type of higher-order modes that can be employed in the realization of the sum and difference patterns for the monopulse feed. The principle of choosing mode ratios for the sum and difference channels is presented and an optimum set of mode ratios are derived. With the derived mode ratios, we compute and plot the aperture electric field distribution and the resultant radiation patterns.

Establishment of inflammatory model induced by Pseudorabies virus infection in mice

Chun-Zhi Ren 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.2

Background: Pseudorabies virus (PRV) infection leads to high mortality in swine. Despite extensive efforts, effective treatments against PRV infection are limited. Furthermore, the inflammatory response induced by PRV strain GXLB-2013 is unclear. Objectives: Our study aimed to investigate the inflammatory response induced by PRV strain GXLB-2013, establish an inflammation model to elucidate the pathogenesis of PRV infection further, and develop effective drugs against PRV infection. Methods: Kunming mice were infected intramuscularly with medium, LPS, and different doses of PRV-GXLB-2013. Viral spread and histopathological damage to brain, spleen, and lung were determined at 7 days post-infection (dpi). Immune organ indices, levels of reactive oxygen species (ROS), nitric oxide (NO), and inflammatory cytokines, as well as levels of activity of COX-2 and iNOS were determined at 4, 7, and 14 dpi. Results: At 105–106 TCID50 PRV produced obviously neurological symptoms and 100% mortality in mice. Viral antigens were detectable in kidney, heart, lung, liver, spleen, and brain. In addition, inflammatory injuries were apparent in brain, spleen, and lung of PRV-infected mice. Moreover, PRV induced increases in immune organ indices, ROS and NO levels, activity of COX-2 and iNOS, and the content of key pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, interferon-γ and MCP-1. Among the tested doses, 102 TCID50 of PRV produced a significant inflammatory mediator increase. Conclusions: An inflammatory model induced by PRV infection was established in mice, and 102 TCID50 PRV was considered as the best concentration for the establishment of the model.

Comparative Analysis of Water Stress-Responsive Transcriptomes in Drought-Susceptible and -Tolerant Wheat (Triticum aestivum L.)

Yong Chun Li,Fan Rong Meng,Chun Yan Zhang,Ning Zhang,Ming Shan Sun,Jiang Ping Ren,Hong Bin Niu,Xiang Wang,Jun Yin 한국식물학회 2012 Journal of Plant Biology Vol.55 No.5

To understand better the mechanisms that regulate the water stress response in wheat, we conducted a comparative analysis of transcript profiles in roots from two wheat genotypes -- drought-tolerant ‘Luohan No. 2’ (LH)and drought-susceptible ‘Chinese Spring’ (CS). In LH roots,3831 transcripts displayed changes in expression of at least two-fold over the well-watered control when drought treatment was applied. Of these, 1593 were induced while 2238 were repressed. Relatively fewer transcripts were drought-responsive in CS; i.e., 1404 transcripts were induced and 1493 were repressed. In common between LH and CS,569 transcripts were induced and 424 transcripts were repressed. In all, 689 transcripts (757 probe sets) identified from LH and 537 transcripts (575 probe sets) from CS were annotated and classified into 10 functional categories. Among those annotated transcripts from LH and CS that had fold-change ratios of at least 4, 92 induced transcripts were common to both, while 23 transcripts were specifically induced in LH. Gene ontology analysis of these induced genes showed highly significant enrichment for multiple terms related to abiotic stimuli, organic acid biosynthesis,and lipid metabolism. This suggests that these gene groups play important roles during the stress response in LH and CS, and might also be responsible for differences in drought tolerance between those genotypes.

SCM 적용을 위한 중국 패션 유통업체의 시장대응형 프로세스 구축

염인순(Ren Chun Lian),이창호(Chang Ho Lee) 한국SCM학회 2003 한국SCM학회지 Vol.3 No.2

AHP기법을 활용한 韓中(한중) 전통마을의 자원중요도 평가항목 비교

임광순 ( Guang Chun Ren ),왕애하 ( Ai Xia Wang ),김태경 ( Tae Kyung Kim ) 한국전통조경학회 2015 한국전통조경학회지 Vol.33 No.3

본 연구는 전통마을 보전과 개발에 적용할 수 있는 자원 평가기준 및 한국과 중국 전문가들 사이에서 나타나는 전통마을 자원 중요도 차이점을 도출하기 위하여 두 나라 관련 전문가를 대상으로 전통마을 자원에 대하여 AHP기반의 설문조사를 실시하였다. 평가항목은 전통마을 자원의 중요도 및 우선순위 도출을 목표로 3계층으로 구분하였다. 분석결과 Level 1에서는 자연자원, Lavel 2에서는 환경자원, 역사자원, 시설자원, Lavel 3에서는 공기, 지형, 전통주택, 농업경관, 공동생활시설, 도농교류활동, 씨족활동 등의 인자가 중요한 것으로 나타났으며, 한국과 중국 두 그룹에서 가장 중요하다고 평가한 인자는 동일하게 나타났다. 평가항목별 종합적인 중요도는 공기, 수질, 소음, 전통주택, 지형, 공동생활시설 등 인자가 한국과 중국 두 그룹에서 상대적으로 중요한 것으로 나타났다. 즉 전통마을은 문화자원요소들을 보전해야 한다는 필연성을 의무처럼 가지고 있지만 질 좋은 자연환경의 관리가 우선적으로 필요하다. 본 연구의 결과는 한국과 중국 전통마을 자원의 중요도에 대한 비교가 되었을 뿐만 아니라 전통마을의 보전과 관리를 위한 자원별 순위와 배점을 산출함으로써 두 나라 전통마을 자원 평가 시 정량적인 데이터 결과를 각각 적용할 수 있는 방안이 될 것으로 기대한다. This study conducted the survey on the resources of traditional villages based on AHP in the subjects with the specialists in Korea and China to seek the resource evaluation standards to apply the preservation and development of traditional villages, and the differences of the importance on the resources among the specialists in both countries. We classified three levels of evaluation items to aim the deductions of the importance and priority in the resources of traditional villages. Upon the analysis results, natural resources were important in the level 1; environmental, historical, facility resources were important in the level 2; and the factors such as air, topography, traditional houses, agricultural landscape, shared community facilities, interchanges between urban and rural areas, family activities, and so on were important in the level 3. The factors that both Korean and Chinese groups evaluated as the most important ones were the same. In terms of overall importance by evaluation items, the factors such as air, water quality, noise, traditional houses, topography, shared community facilities, and so on were rated as relatively important in both Korean and Chinese groups. That is, the traditional villages have the necessity to preserve the cultural resources like their duties, however, it is required to control the natural environment with good quality preferentially. This study results can compare the importance on the resources of traditional village between Korea and China. Moreover, with calculation of the priority and scores for the preservation and management of traditional villages, they are expected to be used as the tool to apply the quantitative data in the evaluation process of traditional village resources in both countries.

Light-Emitting Diode-Assisted Narrow Band Imaging Video Endoscopy System in Head and Neck Cancer

Hsin-Jen Chang,Wen-Hung Wang,Yen-Liang Chang,Tzuan-Ren Jeng,Chun-Te Wu,Ludovic Angot,Chun-Hsing Lee,Pa-Chun Wang 대한소화기내시경학회 2015 Clinical Endoscopy Vol.48 No.2

Background/Aims: To validate the effectiveness of a newly developed light-emitting diode (LED)-narrow band imaging (NBI) system for detecting early malignant tumors in the oral cavity. Methods: Six men (mean age, 51.5 years) with early oral mucosa lesions were screened using both the conventional white light and LED-NBI systems. Results: Small elevated or ulcerative lesions were found under the white light view, and typical scattered brown spots were identified after shifting to the LED-NBI view for all six patients. Histopathological examination confirmed squamous cell carcinoma. The clinical stage was early malignant lesions (T1), and the patients underwent wide excision for primary cancer. This is the pilot study documenting the utility of a new LED-NBI system as an adjunctive technique to detect early oral cancer using the diagnostic criterion of the presence of typical scattered brown spots in six high-risk patients. Conclusions: Although large-scale screening programs should be established to further verify the accuracy of this technology, its lower power consumption, lower heat emission, and higher luminous efficiency appear promising for future clinical applications.

Energetics and kinetics of Cu atoms and clusters on the Si(111)-7 × 7 surface: first-principles calculations

Ren, Xiao-Yan,Niu, Chun-Yao,Chen, Wei-Guang,Tang, Ming-Sheng,Cho, Jun-Hyung The Royal Society of Chemistry 2016 Physical chemistry chemical physics Vol.18 No.27

<P>Exploring the properties of noble metal atoms and nano- or subnano-clusters on the semiconductor surface is of great importance in many surface catalytic reactions, self-assembly processes, crystal growth, and thin film epitaxy. Here, the energetics and kinetic properties of a single Cu atom and previously reported Cu magic clusters on the Si(111)-(7 x 7) surface are re-examined by the state-of-the-art first-principles calculations based on density functional theory. First of all, the diffusion path and high diffusion rate of a Cu atom on the Si(111)-(7 x 7) surface are identified by mapping out the total potential energy surface of the Cu atom as a function of its positions on the surface, supporting previous experimental hypothesis that the apparent triangular light spots observed by scanning tunneling microscopy (STM) are resulted from a single Cu atom frequently hopping among adjacent adsorption sites. Furthermore, our findings confirm that in the low coverage of 0.15 monolayer (ML) the previously proposed hexagonal ring-like Cu-6 cluster configuration assigned to the STM pattern is considerably unstable. Importantly, the most stable Cu-6/Si(111) complex also possesses a distinct simulated STM pattern with the experimentally observed ones. Instead, an energetically preferred solid-centered Cu-7 structure exhibits a reasonable agreement between the simulated STM patterns and the experimental images. Therefore, the present findings convincingly rule out the tentative six-atom model and provide new insights into the understanding of the well-defined Cu nanocluster arrays on the Si(111)-(7 x 7) surface.</P>

Hydrogen adsorption induced nanomagnetism at the Si(111)- (7×7) surface

Ren, Xiao-Yan,Niu, Chun-Yao,Yi, Seho,Li, Shunfang,Cho, Jun-Hyung American Physical Society 2018 Physical review. B Vol.98 No.19

Synthesis and Application of Benzotriazole UV Absorbers to Improve the UV Resistance of Polyester Fabrics

Chunli Li,Wei Ma,Xuehong Ren 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

In this study, 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole (BTHA), a benzotriazole ultraviolet absorber monomer,was synthesized from 2-(2,4-dihydroxyphenyl)-benzotriazole (BTDP) and acryloyl chloride. The synthesized BTHA wascharacterized by 1H-NMR, FTIR, and ultraviolet spectroscopy, and grafted onto polyester fabrics by the traditional pad-drycure(PDC) process. The effects of monomer concentration and initiator concentration on the UPF values of the grafted PETfabrics were studied. The grafted fabrics were characterized by scanning electron microscopy (SEM), X-ray photoelectronspectroscopy (XPS), and thermogravimetric analysis (TGA). The breaking strength of the grafted PET fabrics wascomparable with the original PET fabrics in warp and weft directions. The UV protection factors improved significantly aftergrafting. The modified PET fabrics exhibited good durability to washing. The grafting of BTHA onto PET fabrics protectedthe damage of UV light to PET fabrics and decreased the strength loss of PET fabrics after UVA light exposure.

Inorganic-organic Hybrid Nanoparticles and Their Application on PET Fabrics for UV Protection

Chunli Li,Rong Li,Xuehong Ren 한국섬유공학회 2020 Fibers and polymers Vol.21 No.2

In this paper, we reported the synthesis of TiO2/γ-(methacryloyloxy)propyltrimethoxysilane (KH570) hybrid nanoparticles with simple and mild condition at room temperature. The as-prepared TiO2/KH570 hybrid nanoparticles were characterized by FT-IR, XRD, SEM, EDS, and XPS. The hybrid nanoparticles were coated onto the surfaces of polyethylene terephthalate (PET) fabrics by pad-dry-cure (PDC) process. The morphology, structural, and chemical composition of the coated fabrics were analyzed by SEM, EDS, and XPS. The ultraviolet protection factor (UPF) was used to evaluate the UV protection property of PET fabrics. The coated PET fabric exhibited good UV resistance abilities with a UPF value of 50+. The air permeability of the coated PET fabrics decreased significantly compared with the original PET fabrics. The coated PET fabrics also showed good washing stability. The coated fabrics had an excellent protective effect against ultraviolet rays after exposure to ultraviolet light for a period of time. The PDC process only caused a small degree loss of the tensile strength of the coated PET fabrics.