복원된 양재천에서 복원 효과 평가 및 평가 결과에 기초한 개선방안

김아름,김동욱,임봉순,설재원,이창석,Kim, A Reum,Kim, Dong Uk,Lim, Bong Soon,Seol, Jae Won,Lee, Chang Seok 한국하천호수학회 2020 생태와 환경 Vol.53 No.4

This study was carried out to evaluate the restoration effect in the restored Yangjae stream and to draw up an adaptive management plan based on the results. As the result of evaluation on the restoration effect, the restored Yangjae stream was evaluated with low naturalness in both terms of the morphology of the stream and the composition and spatial distribution of vegetation. The diverse functional groups were introduced in the vegetation restoration, but the flooding regime, which is significant in the spatial distribution of riparian vegetation, were not correctly reflected. Exotic species or species that were not ecologically suitable for the location were introduced on the embankment and thus a measure to improve those problems is required. As the ecological principle was not reflected in the restoration plan, the stream was constructed as the double terrace structure. Therefore, the width of the waterway was narrowed further, and the waterfront was not designed to accommodate changes from flooding disturbance, making the micro-topography of the stream simpler and the naturalness lower. The adaptive management plan was prepared to improve those problems, and a plan for creating an ecological network was recommended to enhance the restoration effect.

IEEE 802.15.4기반 센서 네트워크에서 슬립거부 공격의 취약성 분석 및 탐지 메커니즘

김아름,김미희,채기준,Kim, A-Reum,Kim, Mi-Hui,Chae, Ki-Joon 한국정보처리학회 2010 정보처리학회논문지 C : 정보통신,정보보안 Vol.17 No.1

IEEE 802.15.4[1] has been standardized for the physical layer and MAC layer of LR-PANs(Low Rate-Wireless Personal Area Networks) as a technology for operations with low power on sensor networks. The standardization is applied to the variety of applications in the shortrange wireless communication with limited output and performance, for example wireless sensor or virtual wire, but it includes vulnerabilities for various attacks because of the lack of security researches. In this paper, we analyze the vulnerabilities against the denial of sleep attacks on the MAC layer of IEEE 802.15.4, and propose a detection mechanism against it. In results, we analyzed the possibilities of denial of sleep attacks by the modification of superframe, the modification of CW(Contention Window), the process of channel scan or PAN association, and so on. Moreover, we comprehended that some of these attacks can mount even though the standardized security services such as encryption or authentication are performed. In addition to, we model for denial of sleep attacks by Beacon/Association Request messages, and propose a detection mechanism against them. This detection mechanism utilizes the management table consisting of the interval and node ID of request messages, and signal strength. In simulation results, we can show the effect of attacks, the detection possibility and performance superiorities of proposed mechanism. IEEE 802.15.4 표준기술[1]은 센서 네트워크에서 저전력을 위한 기술로 LR-WPANs(Low Rate-Wireless Personal Area Networks)의 물리 계층과 MAC계층을 규정한다. 이 표준은 무선 센서, 가상 선(Virtual Wire)과 같은 제한된 출력과 성능으로 간단한 단거리 무선 통신을 필요로 하는 폭넓은 응용에 활용되고 있지만 보안 측면의 연구는 현재 미비한 상태로 다양한 공격에 대한 취약점을 내포하고 있다. 본 논문에서는 802.15.4 MAC계층의 슬립거부(Denial of Sleep) 공격에 대한 취약성을 분석하고 이를 탐지하는 메커니즘을 제안한다. 분석 결과, 슈퍼프레임 구간 변경, CW(Contention Window)값 변경, 채널스캔 및 PAN 연합과정 등에서 슬립거부 공격의 가능성을 분석할 수 있었고, 이 과정 중 일부에서는 표준에서 정의한 인증과 암호화 기능이 적용되어도 공격 가능함을 알 수 있었다. 또한 본 논문에서는 분석된 취약점 중에 채널스캔 및 PAN 연합과정에서 Beacon/Association Request 메시지 위조를 통한 슬립거부 공격의 탐지 메커니즘을 제안한다. 제안된 메커니즘은 메시지 요청 간격, 요청 노드 ID, 신호 세기 등을 모니터링하여 공격을 식별하여 탐지한다. QualNet 시뮬레이션 툴을 사용하여 공격의 영향 및 제안된 탐지 메커니즘의 탐지 가능성과 성능의 우수성을 입증할 수 있었다.

PVA 중합도가 고상-액상 혼합 방식에 의한 YAG:Ce³⁺ 형광체 분말 합성에 미치는 영향

김아름,이상진,Kim, A-Reum,Lee, Sang-Jin 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

YAG:$Ce^{3+}$ phosphor powders were synthesized using $Al(OH)_3$ seeds by means of a PVA-polymer-solution route. Various types of PVA with different molecular weights (different polymerization) were used. All dried precursor gels were calcined at $500^{\circ}C$ and then heated at $1500^{\circ}C$ in a mix of nitrogen and hydrogen gases. The final powders were characterized via XRD, SEM, PSA, PL, and PKG analyses. The phosphor properties and morphologies of the synthesized powders were dependent on the PVA type. As the molecular weight of the PVA was increased, the particle size gradually decreased with agglomeration, and the luminous intensity of the phosphor increased. However, the phosphor powder prepared from the PVA exhibiting very high molecular weight, showed a 531 nm (blue) shift from the 541 nm (yellow) wavelength of the YAG:$Ce^{3+}$ phosphor. Finally, the synthesized YAG:$Ce^{3+}$ phosphor powder prepared from the PVA with 89,000 - 98,000 molecular weight showed phosphor properties similar to those of a commercial phosphor powder, but without a post-treatment process.

A Study on the Condition Diagnosis for A Gas-insulated Transformer using Decomposition Gas Analysis

김아름,곽병섭,전태현,박현주,Ah-Reum, Kim,Byeong Sub, Kwak,Tae-Hyun, Jun,Hyun-joo, Park Korea Electric Power Corporation 2022 KEPCO Journal on electric power and energy Vol.8 No.2

A growing number of gas-insulated transformers in underground power substations in urban areas are approaching 20 years of operation, the time when failures begin to occur. It is thus essential to prevent failure through accurate condition diagnosis of the given facility. Various solid insulation materials exist inside of the transformers, and the generated decomposition gas may differ for each gas-insulated equipment. In this study, a simulation system was designed to analyze the deterioration characteristics of SF₆ decomposition gas and insulation materials under the conditions of partial discharge and thermal fault for diagnosis of gas-insulated transformers. Degradation characteristics of the insulation materials was determined using an automatic viscometer and FT-IR. The analysis results showed that the pattern of decomposition gas generation under partial discharge and thermal fault was different. In particular, acetaldehyde was detected under a thermal fault in all types of insulation, but not under partial discharge or an arc condition. In addition, in the case of insulation materials, deterioration of the insulation itself rapidly progressed as the experimental temperature increased. It was confirmed that it was possible to diagnose the internal discharge or thermal fault occurrence of the transformer through the ratio and type of decomposition gas generated in the gas-insulated transformer.

자연정화공법을 이용한 소형 축산폐수처리장치의 최적여재 선정

김아름(Ah-Reum Kim),김홍출(Hong-Chul Kim),서동철(Dong-Cheol Seo),박종환(Jong-Hwan Park),김성헌(Sung-Hun Kim),이성태(Seong-Tae Lee),정태욱(Tae-Uk Jeong),최정호(Jeong-Ho Choi),김현욱(Hyunook Kim),조주식(Ju-Sik Cho),허종수(Jong-Soo Heo) 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.2

소규모 축산농가로부터 발생되는 축산폐수를 효과적으로 처리하기 위한 인공습지를 개발하기 위하여 인공습지에서 가장 중요한 인자 중 하나인 최적 여재의 선정에 관하여 연구하였다. 최적여재를 선정하기 위하여 여재를 왕사, 쇄석, 제올라이트 및 방해석으로 달리하여 충진한 후 각 여재별 축산폐수 처리효율 조사한 결과 COD 처리효율은 왕사가 다른 여재에 비하여 높았고, SS 처리효율은 모든 여재에서 94~95%로 큰 차이 없었다. 또한 T-N 처리효율은 제올라이트가 다른여재에 비해 높았고, T-P 처리효율은 방해석이 다른여재에 비해 높았다. 이상의 결과에서 COD,SS, T-N 및 T-P 모두를 안정적으로 처리할 수 있는 최적여재는 왕사였다. 소형 축산폐수처리장치에서 질소와 인 처리효율을 극대화 하기 위해 호기성조 (왕사:쇄석:방해석=3:2:1)와 혐기성조 (왕사:쇄석:제올라이트=3:2:1)에 혼합여재를 주입한 결과 최적 여재인 왕사에 비해 질소 및 인 처리효율이 각각 15% 및 7% 향상되었다. In order to develop livestock wastewater treatment technology by natural purification method, the optimum filter media in small-scale livestock wastewater treatment apparatus for treating livestock wastewater were studied. Removal rates of pollutants under different filter media were in the other of coarse sand ≒ broken stone > zeolite > calcite for COD, zeolite >> broken stone ≒ coarse sand ≒ calcite for T-N, and calcite > coarse sand ≒ broken stone ≒ zeolite for T-P. Based on the above results, the optimum filter media was coarse sand in small-scale livestock wastewater treatment apparatus. To meet acceptable effluent quality standard for livestock wastewater and to improve T-N and T-P removal efficiencies, removal efficiencies of pollutants in small-scale livestock wastewater treatment apparatus with mixed filter media were studied. The removal rates of COD, SS, T-N and T-P in effluent were 84, 94, 65 and 98% in small-scale livestock wastewater treatment apparatus with mixed filter media, respectively. For increasing the T-N and T-P removals in small-scale livestock wastewater treatment apparatus, the mixed filter media are recommended.

긍정적 사회,정서 함양 프로그램이 다문화 가정 정서,행동장애 위험아동의 정서능력과 사회성 기술에 미치는 영향

김아름 ( A Reum Kim ),박지연 ( Ji Yeon Park ) 한국정서·행동장애아교육학회(구 한국정서학습장애아교육학회) 2015 정서ㆍ행동장애연구 Vol.31 No.2

본 연구에서는 긍정적 사회·정서 함양 프로그램이 다문화 가정 정서·행동장 애 위험아동의 정서능력과 사회성 기술에 미치는 영향을 알아보았다. 연구 참여자 는 서울 소재의 한 다문화 학교에 재학 중인 정서·행동장애 위험 다문화 가정 초 등학생 12명이며, 이들을 대상으로 총 16회기에 걸쳐 긍정적 사회·정서 함양 프로 그램을 실시하였다. 연구 참여자들의 정서능력과 사회성 기술에 대한 사전-사후 간 변화와 프로그램 효과의 유지 여부를 확인하기 위해 기술통계, 종속표본 t검정, 현 장 일지와 동영상 관찰 등을 통한 질적 자료 분석을 실시하였다. 연구 결과, 긍정 적 사회·정서 함양 프로그램은 다문화 가정 정서·행동장애 위험아동의 정서능력, 사회성 기술에는 대체로 긍정적인 영향을 미쳤으나, 프로그램이 종료된 지 12주 후 에 종속변인을 다시 측정한 결과, 중재 효과가 유지되지는 않은 것으로 나타났다. 마지막으로 본 연구 결과에 대한 논의와 연구의 제한점을 제시하였다. The purpose of this study is to examine the effects of the positive social-emotional improvement program on emotional competency and social skills of children at risk for emotional and behavioral disorders from multi-cultural families. The participants consist of twelve students at risk for emotional and behavioral disorders who attend a multi-cultural alternative school located in Seoul. This program proceeded for sixteen sessions once a week. In order to examine the effects of the program, the emotional competency scale and Social Skills Rating Scales(SSRS) were used. One group pre-post design was applied for this study and dependent samples t-tests with descriptive statistics were used for data analyses. Additionally, qualitative analyses using field notes and video observations were conducted. The results showed that the intervention improved the participants’ emotional competency and self-reported social skills. No significant change was found in teacher-reported social skills. However, the intervention effects were not maintained up to 12 weeks. Finally, discussions of the results and the limitations of the study were presented.

목형 잎 추출물의 항산화 활성과 멜라닌 생합성에 대한 저해활성

김아름 ( A Reum Kim ),박수아 ( Su Ah Park ),하지훈 ( Ji Hoon Ha ),박수남 ( Soo Nam Park ) 한국미생물생명공학회(구 한국산업미생물학회) 2013 한국미생물·생명공학회지 Vol.41 No.1

본 연구에서는 목형 잎 추출물의 항산화 활성, 성분분석 그리고 mushroom tyrosinase 저해활성 측정, α-MSH로 유도된 세포 내 멜라닌 생합성에 대한 저해활성에 관한 연구를 수행하였다. 목형 잎 추출물의 자유라디칼 (1,1-diphenyl- 2-picrylhydrazyl, DPPH) 소거활성 (FSC50)은 에틸아세테이트 분획에서 14.51 μg/ml, 아글리콘 분획에서 13.96 μg/ml로 측정되었다. Luminol-의존성 화학발광법을 이용한 Fe3+- EDTA/H2O2 계에서 생성된 활성산소종 (reactive oxygen species, ROS)에 대한 목형 잎 추출물의 총항산화능은 아글리콘 분획에서 0.22 μg/ml로, 아글리콘 분획에서 가장 큰 활성을 나타내었다. 목형 잎 추출물에 대하여 rose-bengal로 증감된 1O2에 의한 적혈구 파괴에 대한 세포보호 효과는 모든 분획에서 농도 의존적(1~50 μg/ml)으로 증가하였으며, 특히 아글리콘 분획에서 지용성 항산화제인 (+)-α-tocopherol 보다 우수한 세포보호 활성이 있는 것으로 나타났다. Mushroom tyrosinase의 활성 저해 효과(IC50)를 측정한 결과 에틸아세테이트 분획(IC50 = 48.58 μg/ml)에서 우수한 효과를 나타났고, α-MSH로 유도된 세포 내 멜라닌 합성 저해 활성을 측정한 결과 에틸아세테이트 분획물의 50 μg/ml 농도에서 41.80% 저해활성을 나타내었다. TLC, HPLC 및 LC/ESIMS를 이용한 성분분석 결과 에틸아세테이트 분획 중에 luteolin, isoorientin이 존재함을 확인하였다. 이상의 결과들로부터 목형 잎 추출물은 활성산소종을 소거하는 항산화제로 이용가능하며, 특히 mushroom tyrosinase 저해효과와 α- MSH로 유도된 멜라닌 생합성 저해 효과로부터 에틸아세테이트 분획 중 luteolin 및 isoorientin을 새로운 미백 화장품의 원료로써 이용가능성을 알 수 있었다. The aim of this study was to evaluate various aspects of Vitex negundo L. leaf extract, such as the antioxidative activity, tyrosinase inhibitory effects, and inhibitory activities on α-MSH induced melanogenesis, and active component analysis. The DPPH (1, 1-diphenyl-2-picrylhydrazyl) scavenging activities (FSC50) of the ethyl acetate fraction and aglycone fraction of V. negundo L. leaf extract were 14.51 μg/ml and 13.96 μg/ml, respectively. A luminol-dependent chemiluminescence assay revealed that the reactive oxygen species (ROS) scavenging activity (OSC50) of the aglycone fraction of V. negundo L. leaf extract on ROS generated in an Fe3+-EDTA/H2O2 system was the most prominent at 0.22 μg/ml. The protective effects of the extracts fractions of V. negundo L. leaf against the rose-bengal sensitized photohemolysis of human erythrocytes were increased in a concentration dependent manner (1~50 μg/ml). In particular, there were greater protective effects of the aglycone fraction on the cellular membrane than that of the fat-soluble antioxidant (+)-α-tocopherol. The inhibitory effects (IC50) on mushroom tyrosinase were the highest for the ethyl acetate fraction (IC50 = 48.58 μg/ml). The inhibitory effect on α-MSH induced melanogenesis in B16 melanoma cells was 41.80% at 50 μg/ml of ethyl acetate fraction. Active component analyses by TLC, HPLC and LC/ESI MS revealed luteolin and isoorientin. These results indicate that V. negundo L. leaf extract can be used as an antioxidant for ROS scavenging. Particularly, the luteolin and isoorientin of the ethyl acetate fraction may be applicable to new whitening cosmetics because of its inhibitory effect on mushroom tyrosinase and α-MSH induced melanogenesis in B16 melanoma cells.

헤어살롱의 관계마케팅이 살롱선택속성과 고객만족에 미치는 영향

김아름 ( Ah Reum Kim ),전근옥 ( Gun Ok Jun ),조현진 ( Hyeon Jin Jo ),박은준 ( Eun Jun Park ) 한국미용학회 2020 한국미용학회지 Vol.26 No.5

The recent diversification of consumer tastes has caused supply to exceed demand, shifting the market's lead from businesses to heads. In this competitive market environment, hair salons are experiencing major difficulties in management, and attracting customers among them is a major problem. In this study, the effect of relationship marketing on saloon selection and satisfaction is found among customers using salons and the design of programs to attract customers is significant. The questionnaire was used in the study and the collected data was analyzed using SPS 22.0. To determine the effect between each parameter, the effect of the parameter was determined using regression and parametric regression. The results showed that unmarried women in their 20s had the highest response rate, the average monthly Sodden was between 2 and 3 million, the grade was college students, and the profession was the highest. Relationship marketing was derived from operation services and communication, and customer satisfaction was derived with brand attributes, internal attributes and external attributes, with the degree of satisfaction, recommendation and revisit. Each parameter was shown to affect each other. It is expected that the number of new customers will increase through the recommendation of fixed customers by making efforts to communicate with customers and establishing a revisit system and membership system in Salon.

인공지능 기반 로보어드바이저(Robo-advisor) 사용의사결정에 대한 탐색적 연구

김아름(Kim, A Reum),앙혜경(Yang, Hae Kyung) 한국경영교육학회 2021 경영교육연구 Vol.36 No.1

[연구목적] 로보어드바이저는 인공지능을 기반으로 온라인에서 투자자문이나 투자관리를 제공하는 자동화된 투자관리서비스로 최근 들어 로보어드바이저 시장이 성장하고 있는 것에 비해 로보어드바이저 사용자 관점에서의 연구는 부족한 실정이다. 본 연구는 로보어드바이저 사용자의 사용의사결정에 대한 심층적인 이해를 위해 심층 인터뷰를 수행하여 로보어드바이저 사용행동의 맥락을 이해하는 것이 목적이다. [연구방법] 로보어드바이저 사용자를 대상으로 진행한 심층 인터뷰 텍스트는 NVivo Release 1을 활용하여 분석하였으며, 근거이론을 기반으로 축 코딩 패러다임모형을 시행하였다. 패러다임모형은 인과적 조건, 맥락적 조건, 중심현상, 중재적 조건, 전략, 결과로 구성된다. [연구결과] 로보어드바이저 사용자는 로보어드바이저의 특수성(객관성, 수익성, 다양성, 편의성, 전문성)에 대한 인식을 통해 로보어드바이저를 사용하게 되며, 사용에 이르는 구조적 상황은 시장 변동성, 저금리, 전통 금융권에 대한 불신 및 로보어드바이저 정보의 접근성, 투자대안부재인 것으로 나타났다. 로보어드바이저 업체 및 기술에 대한 인식, 사용자 자신감이 로보어드바이저 사용전략을 촉진하거나 억제하는 조건으로 도출되었으며, 전략으로는 상업적 정보원천 및 사용자 주도적 정보원천을 활용하는 것으로 나타났다. 이후 로보어드바이저 유지, 해지, 정보제공 및 추천과 같은 사용 후 행동과 산업 성장에 대한 기대감 형성이 결과로 나타났다. [연구의 시사점] 본 연구의 학문적 의의는 로보어드바이저 사용자의 인지적 및 행동적 측면을 고려한 탐색적 연구로서 사용의사결정모형을 도출하고자 한 데 있다. 실무적으로는 로보어드바이저와 상호작용하는 사용자의 관점에서 로보어드바이저 사용의사결정의 맥락을 파악함으로 로보어드바이저에 대한 인식을 제고하고, 도출된 요인들을 통해 사용자 친화적 서비스로 개선하는데 실질적인 시사점을 제공한다. [Purpose] Robo-advisor is an automated investment management using algorithms that provides financial investment advice or investment management online. It became more popular with low interest rate and advances in artificial intelligence technology. This study explores the decision making process of robo-advisor users in Korea. [Methodology] We interviewed 15 robo-advisor users, and analyzed the text using NVivo Release 1 software. Based on paradigm analysis of the axial coding, we identified causal conditions, contextual conditions, central phenomenon, intervention conditions, strategies and consequence in robo-advisor users’ decision making process. [Findings] Our results show robo-advisor users started using robo-advisor services because of the specific features of robo-advisor such as objectivity, profitability, diversity, convenience, and expertise. Contextual conditions are identified as market volatility, low interest rate, distrust of traditional investment institutions, access to information on robo-advisors, and lack of investment alternatives. User’s strategy includes searching for commercial and user-driven information. Consequences include maintaining or terminating robo-advisor subscription, providing information or recommending robo-advisor to others. Based on these, a model of robo-advisor users’ decision making process was constructed. [Implications] Our results provide implications to the robo-advisor service providers with information on robo-advisor users decision making process. With our results, robo-advisor service providers can improve their services more user-friendly, and focus on gaining trust by users. Regulators need to consider more on user-protection while regulating robo-advisor industry.

프랜차이즈 헤어살롱 인턴의 교육에 대한 만족, 활용, 직업몰입에 관한 연구

김아름 ( Ah Reum Kim ),박은준 ( Eun Jun Park ) 한국미용학회 2018 한국미용학회지 Vol.24 No.2

The purpose of this study is to examine the relationship among the satisfaction of the education, educational application, and occupational commitment of all interns at franchise hair salons. In addition it focuses on analyzing factors that increase occupational commitment to contribute the most important educational programs in human resources management with strong guidance. As for the subject of this study, a total of 270 questionnaires were distributed, and 250 of them were retrieved and statistical data was obtained with 244 valid questionnaires. SPSS 22.0 was used to analyze the collected data. Analytical analysis was carried out on the data in the form of frequency analysis, factor analysis, reliability analysis, and regression analysis. First of all, interns’ satisfaction of the education influenced the relationship commitments in the order of the satisfaction of the education system and the gratification of the education effect. Secondly, educational application has a significant effect on relationship commitment in the order of practical, psychological, and theoretical aspects, and on occupational commitment in order of psychological, theoretical, and practical aspects. In conclusion, on the basis of this research, it can be seen that companies should develop their employees’ abilities to provide psychological stability, a sense of belonging, and systematize level-specific education according to their ability to work. In addition, to provide high quality service to customers, they should investigate the satisfaction of employees' education and improve the quality of education. Furthermore, they should elevate employees’ minds so that they have confidence in their jobs, responsibility for their duties and solid work ethic.