Time Coordinated V2I Communications and Handover for WAVE Networks

Jong-Moon Chung,Minseok Kim,Yong-Suk Park,Myungjun Choi,Sangwoo Lee,Hyun Seo Oh IEEE 2011 IEEE journal on selected areas in communications Vol.29 No.3

<P>A wide variety of information technology (IT) services will become available for vehicles through the IEEE 802.11p, IEEE 1609, and wireless access in vehicular environment (WAVE) standards, and naturally the need for service handover will become a necessity. For WAVE networks, a time coordinated medium access control (MAC) protocol named WAVE point coordination function (WPCF) is proposed in this paper. The mathematical derivations and simulation analysis demonstrate that the proposed WPCF protocol can significantly enhance the utilization efficiency and can support more users based on an equal-length access period when compared to point coordination function (PCF), enhanced distributed channel access (EDCA), or hybrid coordination function (HCF) controlled channel access (HCCA) for vehicle to infrastructure (V2I) communications. The paper also demonstrates the effectiveness of the proposed WAVE handover controller (WHC) and WPCF in minimizing service disconnection time when used for V2I handover. In addition, technical enhancements and messages are added to enable seamless communication services over soft-handover (SHO), and enable minimum handover delay in hard-handover (HHO) situations. The mathematical performance evaluation and the simulation results show that the proposed scheme can significantly improve the handover latency compared to the performance that can be delivered by the current protocols.</P>

굴절률(IOR) 기반 사실적 재질표현 프로세스 - 옥테인 렌더러를 활용한 리바트 프로모션 영상을 중심으로

박명준(Myungjun Park),문현정(Hyunjung Moon) 한국디자인학회 2022 한국디자인학회 학술발표대회 논문집 Vol.2022 No.5

빈집 발생에 미치는 지역 환경요인 분석

장명준(Jang, Myungjun),권성문(Kwon, Sung Moon) 한국도시행정학회 2021 도시 행정 학보 Vol.34 No.2

우리나라의 도시에서 빈집의 문제는 단순히 지나가는 현상이 아닌 고질적인 사회문제의 시작점으로 인지되고 있다. 이 연구는 빈집 발생과 지역 환경요인의 관계를 실증적으로 분석하는 것을 주목적으로 진행하였다. 분석의 데이터는 전주시의 등급별 빈집 데이터를 이용하였으며 지역군집분석과 음이항회귀분석을 연구방법으로 채택하여 연구를 수행하였다. 분석결과 첫째, 빈집은 구도심에 공간적으로 집중되었으며 불량빈집의 경우에는 산업단지에 밀집되어 있었다. 둘째, 고령인구가 많은 지역에서 불량빈집 확률이 높게 나타났다. 셋째, 지방도와 시 · 군도에 대한 접근성은 불량빈집 발생을 감소시키는 중요한 역할을 하는 것으로 나타났다. 넷째, 편의시설 중 보육시설이나 병원은 빈집 발생 확률을 감소시키는 것으로 나타났다. 마지막으로 토지이용혼합도가 높을수록 빈집 발생 확률이 감소하는 것으로 나타났다. 이 연구는 빈집과 지역환경 요인에 대한 관계성을 보여주는데 기여하여 향후 정책적 분석과 대응을 위한 기반을 제공할 것이다. Unoccupied and badly maintained houses have become sources of serious social problems in Korean Urban areas. This study tries to understand the relationship between vacant housing and local environmental factors. With the data of Jeonju city’s vacant housing, this study adopts LISA analysis and Negative Binomial Regression Analysis as research methods. The result shows followings. First, vacant housing is spatially clustered in old city areas. Especially, badly maintained vacant housing is frequently observed in industrial complex. Second, the higher possibilities of clustering vacant housing where senior citizens are concentrated. Third, the local road network accessibility is associated to a lower possibility of clustering vacant housing. Fourth, childcare facilities and hospitals have a negative association with clustering of vacant housing. Last, the mixed land use is negatively associated with a possibility of clustering vacant housing. The results of this study will provide the fundamental information for appropriate policies of vacant housing.

Antifouling and Removal Efficiency of Foul‐Release Polydimethylsiloxane‐based Coatings: Lab‐Scale and Seawater Immersion Fouling Test and Hydrodynamic Shearing Test

Lee Donguk,Choi Seungyong,Moon Myungjun,Shon Minyoung 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.4

Antifouling is necessary to prevent the fouling of marine organisms on ship surfaces in seawater. Foul release (FR) coatings are considered an alternative to commercial antifouling coatings as eco-friendly coating materials that can prevent toxic biocide emissions. However, the evaluation of FR coatings for antifouling is extremely complicated owing to their foul-releasing mechanism with diverse surface properties. Therefore, a reliable laboratory simulation of the actual seawater immersion condition is required. Silicon-based FR coatings with several additives were prepared to evaluate the reliability of a laboratory fouling test. To simulate the marine foulant removal efficiency of an FR coating surface based on the ship speed, a circulating seawater channel was applied. Laboratory test showed a similar tendency as the seawater immersion. From the results, laboratory-scale microalgae fouling tests and circulating seawater channel tests are considered suitable for evaluating the antifouling performance of FR coatings.

Quantitative MALDI-TOF mass spectrometric analysis of biocidal polyhexamethylene guanidine (PHMG) oligomers in consumer products

Bae, Jung-eun,Park, Myungjun,Lee, Jung-min,Song, Insu,Ju, Yunha,Lee, Choong Sik,Kwon, Jung-Hwan,Moon, Bongjin,Oh, Han Bin ELSEVIER 2019 INTERNATIONAL JOURNAL OF MASS SPECTROMETRY Vol.435 No.-

<P><B>Abstract</B></P> <P>In Korea, biocides, which were used for sterilizing household humidifiers, caused a large number of casualties. The biocides used were either guanidine-containing oligomers, such as polyhexamethylene guanidine (PHMG), or thiazolinone-based small molecules such as methylisothiazolinone/methylchloroisothiazolinone (MIT/CMIT). For the guanidine-containing oligomers, a quantitative analysis method has not yet been developed, as the quantification of the oligomers is very challenging due to their polydispersed molecular weight distribution. In this paper, we describe a new MALDI-TOF mass spectrometry (MS)-based quantitative analysis method for the PHMG oligomers contained in wet wipe products. Quantification was made using internal standard <SUP>13</SUP>C labeled PHMG oligomers that were custom synthesized. To get rid of matrix molecules, for example, polyethylene glycols (PEGs), included in the wet wipes, solid phase extraction (SPE) with an MCX SPE cartridge was carried out. In addition, an ionic liquid matrix (ILM) of 1-methylimadazolium α-cyano-4-hydroxycinnamate (1-MeIm-CHCA) was used to improve the reproducibility of the MALDI-TOF MS measurements. This new quantitative analysis method was validated, and good linearity was obtained in the calibration plot. This approach is expected to be equally applicable to other guanidine-containing oligomers, such as polyhexamethylene biguanide (PHMB) and oligo-(2-(2-ethoxy)-ethoxyethyl)-guanidinium-chloride (PGH) as well as to other consumer products.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This is the first report to quantitatively analyze PHMG oligomers that are known to be lethal when inhaled in the long term. </LI> <LI> An ionic liquid matrix was used to minimize shot-to-shot, spot-to-spot, and sample-to-sample heterogeneity. </LI> <LI> For the oligomer mass-spectrometry-based quantitative analysis, an isotope-labelled PHMG oligomer was synthesized and used as an internal standard. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Separation of azeotropic Acetonitrile/water mixture by pervaporation technique through polymeric blend membrane

Shivshankar Chaudhari,YongSung Kwon,ChiYoung Park,MyungJun Moon,MinYoung Shon,SeungEun Nam,YouIn Park 한국막학회 2017 한국막학회 총회 및 학술발표회 Vol.2017 No.11

Blended membranes of hydrophilic polymers poly (vinyl alcohol) (PVA) and poly(vinyl amine) (PVAm) were prepared and crosslinked with glutaraldehyde. The characterization of membranes were done by using FTIR, XRD, DSC, SEM and swelling study. MB1.5 membrane was the best one in all since it exhibited higher separation index. By using blend membrane (MB1.5), the flux through a 65-mm film increased from 0.01 to 0.47 kg/m2h at an acetonitrile/water feed ratio between 20/80 and 5/95 w/w at 30°C while separation factor increased from the 5055 to 100.84 attributed to the higher hydrophilicity of blend membranes. On comparison of pervaporation data with water-acetonitrile vapor-liquid equilibrium data it was observed that the membrane acted as third phase to effectively break the azeotropes.

Na-Y 제올라이트가 첨가된 PVA/PAA 분리막의 아세트산 수용액에서 투과 증발 연구

권용성 ( Yongsung Kwon ),( Shivshankar Chaudhari ),문명준 ( Myungjun Moon ),손민영 ( Minyoung Shon ),박아름이 ( Ahrumi Park ),김영미 ( Youngmi Kim ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.6

Membranes were prepared by incorporating Na-Y zeolite particles into poly(vinyl alcohol) (PVA) cross-linked with poly(acrylic acid) (PAA). The membrane was characterized by FT-IR spectroscopy, contact angle measurement, swelling test, SEM analysis, and XRD analysis. The pervaporation separation of water/acetic acid mixtures was carried out using prepared membranes. From the results, it was shown that the hydrophilic property of prepared membrane increased with increase of zeolite contents and the PVA/PAA membrane with zeolite addition showed higher permeation flux than that of without zeolite membrane. The PVA/PAA membrane containing 8 wt% zeolite showed the highest perme-ation flux and separation in the feed solution containing 10 wt% acetic acid.

PVA based mixed matrix membrane for Isopropanol dehydration using Pervaporation assembly

Shivshankar Chaudhari,YongSung Kwon,ChiYoung Park,MyungJun Moon,MinYoung Shon,SeungEun Nam,YouIn Park 한국막학회 2017 한국막학회 총회 및 학술발표회 Vol.2017 No.11

The modification of Silicotungstic acid (STA) was done by Melamine and Mixed matrix membranes from the Melamine modified Silico tungstic acid (M-STA) particles were prepared for the pervaporation dehydration of Water -Isopropanol (IPA) mixture. The characterization of the membranes were done by FTIR, SEM, EDS AFM XRD, and contact angle measurements. The M-STA loaded composite membranes showed improved pervaporation performance in comparison to the virgin membrane. The 8 wt% M-STA loaded (M8-MSTA) membrane gave an optimum pervaporation performance having flux = 0.36 kg/m2h, separation factor 485.6 for 20 wt% water -isopropanol feed composition at 60 0C was observed.

온사이트 수소충전소용 수증기개질 이중관 반응기 개선 및 공정최적화

이재원(Jaewon Lee),김영진(Youngjin Kim),문일(Il Moon),김명준(Myungjun Kim) 한국신재생에너지학회 2020 한국신재생에너지학회 학술대회논문집 Vol.2020 No.8

Basic amino acid-mediated cationic amphiphilic surfaces for antimicrobial pH monitoring sensor with wound healing effects

Lee Dong Uk,Kim Se-Chang,최동윤,Jung Won-Kyo,Moon Myungjun 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background The wound healing process is a complex cascade of physiological events, which are vulnerable to both our body status and external factors and whose impairment could lead to chronic wounds or wound healing impediments. Conventional wound healing materials are widely used in clinical management, however, they do not usually prevent wounds from being infected by bacteria or viruses. Therefore, simultaneous wound status monitoring and prevention of microbial infection are required to promote healing in clinical wound management. Methods Basic amino acid-modified surfaces were fabricated in a water-based process via a peptide coupling reaction. Specimens were analyzed and characterized by X-ray photoelectron spectroscopy, Kelvin probe force microscopy, atomic force microscopy, contact angle, and molecular electrostatic potential via Gaussian 09. Antimicrobial and biofilm inhibition tests were conducted on Escherichia coli and Staphylococcus epidermidis. Biocompatibility was determined through cytotoxicity tests on human epithelial keratinocytes and human dermal fibroblasts. Wound healing efficacy was confirmed by mouse wound healing and cell staining tests. Workability of the pH sensor on basic amino acid-modified surfaces was evaluated on normal human skin and Staphylococcus epidermidis suspension, and in vivo conditions. Results Basic amino acids (lysine and arginine) have pH-dependent zwitterionic functional groups. The basic amino acid-modified surfaces had antifouling and antimicrobial properties similar to those of cationic antimicrobial peptides because zwitterionic functional groups have intrinsic cationic amphiphilic characteristics. Compared with untreated polyimide and modified anionic acid (leucine), basic amino acid-modified polyimide surfaces displayed excellent bactericidal, antifouling (reduction ~ 99.6%) and biofilm inhibition performance. The basic amino acid-modified polyimide surfaces also exhibited wound healing efficacy and excellent biocompatibility, confirmed by cytotoxicity and ICR mouse wound healing tests. The basic amino acid-modified surface-based pH monitoring sensor was workable (sensitivity 20 mV pH− 1) under various pH and bacterial contamination conditions. Conclusion Here, we developed a biocompatible and pH-monitorable wound healing dressing with antimicrobial activity via basic amino acid-mediated surface modification, creating cationic amphiphilic surfaces. Basic amino acid-modified polyimide is promising for monitoring wounds, protecting them from microbial infection, and promoting their healing. Our findings are expected to contribute to wound management and could be expanded to various wearable healthcare devices for clinical, biomedical, and healthcare applications.