• Title/Summary/Keyword: 통신 성능

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Earthquake Monitoring : Future Strategy (지진관측 : 미래 발전 전략)

  • Chi, Heon-Cheol;Park, Jung-Ho;Kim, Geun-Young;Shin, Jin-Soo;Shin, In-Cheul;Lim, In-Seub;Jeong, Byung-Sun;Sheen, Dong-Hoon
    • Geophysics and Geophysical Exploration
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    • v.13 no.3
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    • pp.268-276
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    • 2010
  • Earthquake Hazard Mitigation Law was activated into force on March 2009. By the law, the obligation to monitor the effect of earthquake on the facilities was extended to many organizations such as gas company and local governments. Based on the estimation of National Emergency Management Agency (NEMA), the number of free-surface acceleration stations would be expanded to more than 400. The advent of internet protocol and the more simplified operation have allowed the quick and easy installation of seismic stations. In addition, the dynamic range of seismic instruments has been continuously improved enough to evaluate damage intensity and to alert alarm directly for earthquake hazard mitigation. For direct visualization of damage intensity and area, Real Time Intensity COlor Mapping (RTICOM) is explained in detail. RTICOM would be used to retrieve the essential information for damage evaluation, Peak Ground Acceleration (PGA). Destructive earthquake damage is usually due to surface waves which just follow S wave. The peak amplitude of surface wave would be pre-estimated from the amplitude and frequency content of first arrival P wave. Earthquake Early Warning (EEW) system is conventionally defined to estimate local magnitude from P wave. The status of EEW is reviewed and the application of EEW to Odesan earthquake is exampled with ShakeMap in order to make clear its appearance. In the sense of rapidity, the earthquake announcement of Korea Meteorological Agency (KMA) might be dramatically improved by the adaption of EEW. In order to realize hazard mitigation, EEW should be applied to the local crucial facilities such as nuclear power plants and fragile semi-conduct plant. The distributed EEW is introduced with the application example of Uljin earthquake. Not only Nation-wide but also locally distributed EEW applications, all relevant information is needed to be shared in real time. The plan of extension of Korea Integrated Seismic System (KISS) is briefly explained in order to future cooperation of data sharing and utilization.

A study on the developmental plan of Alarm Monitoring Service (기계경비의 발전적 대응방안에 관한 연구)

  • Chung, Tae-Hwang;So, Seung-Young
    • Korean Security Journal
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    • no.22
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    • pp.145-168
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    • 2010
  • Since Alarm Monitoring Service was introduced in Korea in 1981, the market has been increasing and is expected to increase continually. Some factors such as the increase of social security need and the change of safety consciousness, increase of persons who live alone could be affected positively on Alarm Monitoring Service industry. As Alarm Monitoring Service come into wide use, the understanding of electronic security service is spread and consumer's demand is difficult, so consideration about new developmental plan is need to respond to the change actively. Electronic security system is consist of various kinds of element, so every element could do their role equally. Alarm Monitoring Service should satisfy consumer's various needs because it is not necessary commodity, also electronic security device could be easily operated and it's appearance has to have a good design. To solve the false alarm problem, detection sensor's improvement should be considered preferentially and development of new type of sensor that operate dissimilarly to replace former sensor is needed. On the other hand, to settle the matter that occurred by response time, security company could explain the limit on Alarm Monitoring System to consumer honestly and ask for an understanding. If consumer could be joined into security activity by security agent's explanation, better security service would be provided with mutual confidence. To save response time the consideration on the introduction of GIS(Global Information System) is needed rather than GPS(Global Positioning System). Although training program for security agents is important, several benefits for security agents should be considered together. The development of new business model is required for preparation against market stagnation and the development of new commodity to secure consumer for housing service rather than commercial facility service. for the purpose of those, new commodity related to home-network system and video surveillance system could be considered, also new added service with network between security company and consumer for a basis is to be considered.

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A 1.1V 12b 100MS/s 0.43㎟ ADC based on a low-voltage gain-boosting amplifier in a 45nm CMOS technology (45nm CMOS 공정기술에 최적화된 저전압용 이득-부스팅 증폭기 기반의 1.1V 12b 100MS/s 0.43㎟ ADC)

  • An, Tai-Ji;Park, Jun-Sang;Roh, Ji-Hyun;Lee, Mun-Kyo;Nah, Sun-Phil;Lee, Seung-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.7
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    • pp.122-130
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    • 2013
  • This work proposes a 12b 100MS/s 45nm CMOS four-step pipeline ADC for high-speed digital communication systems requiring high resolution, low power, and small size. The input SHA employs a gate-bootstrapping circuit to sample wide-band input signals with an accuracy of 12 bits or more. The input SHA and MDACs adopt two-stage op-amps with a gain-boosting technique to achieve the required DC gain and high signal swing range. In addition, cascode and Miller frequency-compensation techniques are selectively used for wide bandwidth and stable signal settling. The cascode current mirror minimizes current mismatch by channel length modulation and supply variation. The finger width of current mirrors and amplifiers is laid out in the same size to reduce device mismatch. The proposed supply- and temperature-insensitive current and voltage references are implemented on chip with optional off-chip reference voltages for various system applications. The prototype ADC in a 45nm CMOS demonstrates the measured DNL and INL within 0.88LSB and 1.46LSB, respectively. The ADC shows a maximum SNDR of 61.0dB and a maximum SFDR of 74.9dB at 100MS/s, respectively. The ADC with an active die area of $0.43mm^2$ consumes 29.8mW at 100MS/s and a 1.1V supply.

Developmental Plan of Man-Overboard Alert Devices of Small Fishing Vessels: A Study (소형어선의 선외추락 경보장치 개발 방안 연구)

  • Kim, Jae-Won;Kim, Byung-Ok;Lim, Jung-Gyun;Lee, Ju-Han;Yim, Jea-Hong;Park, Dong-Kook
    • Journal of Navigation and Port Research
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    • v.42 no.4
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    • pp.245-252
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    • 2018
  • A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

LCD 연구 개발 동향

  • 이종천
    • The Magazine of the IEIE
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    • v.29 no.6
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    • pp.76-80
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    • 2002
  • 'Liquid Crystal의 상전이(相轉移)와 광학적 이방성(異方性)이 1888년과 1889년 F. Reinitzer와 O. Lehmann에 의해 Monatsch Chem.과 Z.Physikal.Chem.에 각각 보고된 후 부터 제2차 세계대전이 끝난 뒤인 1950년대 까지는 Liquid Crystal을 단지실험실에서의 기초학문 차원의 연구 대상으로만 다루어 왔다. 1963년 Williams가 Liquid Crystal Device로는 최초로 특허 출원을 하였으며, 1968년 RCA사의 Heilmeier등은 Nematic 액정(液晶)에 저주파(低周波) 전압(電壓)을 인가하면 투명한 액정이 혼탁(混濁)상태로 변화하는 '동적산란(動的散亂)'(Dynamic Scattering) 현상을 이용하여 최초의 DSM(Dynamic Scattering Mode) LCD(Liquid Crystal Display)를 발명하였다. 비록 150V 이상의 높은 구동전압과 과소비전력의 특성 때문에 실용화에는 실패하였지만 Guest-Host효과와 Memory효과 등을 발견하였다. 1970년대에 이르러 실온에서 안정되게 사용 가능한 액정물질들이 합성되고(H. Kelker에 의해 MBBA, G. Gray에 의한 Cyano-Biphenyl 액정의 합성), CMOS 트랜지스터의 발명, 투명도전막(ITO), 수은전지등의 주변기술들의 발전으로 인하여 LCD의 상품화가 본격적으로 이루어지게 되었다. 1971년에는 M. Shadt, W. Helfrich, J.L. Fergason등이 TN(Twisted Nematic) LCD를 발명하여 전자 계산기와 손목시계에 응용되었고, 1970년대 말에는 Sharp에서 Dot Matrix형의 휴대형 컴퓨터를 발매하였다. 이러한 단순 구동형의 TN LCD는 그래픽 정보를 표시하는 데에는 품질의 한계가 있어 1979년 영국의 Le Comber에 의해 a-Si TFT(amorphous Silicon Thin Film Transistor) LCD의 연구가 시작되었고, 1983년 T.J. Scheffer, J. Nehring, G. Waters에 의해 STN(Super Twisted Nematic) LCD가 창안되었고, 1980년 N. Clark, S. Lagerwall 및 1983년 K.Yossino에 의해 Ferroelectric LCD가 등장하여 LCD의 정보 표시량 증대에 크게 기여하였다. Color화의 진전은 1972년 A.G. Ficher의 셀 외부에 RGB(Red, Green, Blue) filter를 부착하는 방안과, 1981년 T. Uchida 등에 의한 셀 내부에 RGB filter를 부착하는 방법에 의해 상품화가 되었다. 1985년에는 J.L. Fergason에 의해 Polymer Dispersed LCD가 발명되었고, 1980년대 중반에 이르러 동화상(動畵像) 표시가 가능한 a-Si TFT LCD의 시제품(試製品) 개발이 이루어지고 1990년부터는 본격적인 양산 시대에 접어들게 되었다. 1990년대 초에는 STN LCD의 Color화 및 대형화(大型化) 고(高)품위화에 힘입어 Note-Book PC에 LCD가 본격적으로 적용이 되었고, 1990년대 후반에는TFT LCD의 표시품질 대비 가격경쟁력 확보로 인하여 Note-Book PC 시장을 독점하기에 이르렀다. 이후로는 TFT LCD의 대형화가 중요한 쟁점으로 부각되고 있고, 1995년 삼성전자는 당시 세계최대 크기의 22' TFT LCD를 개발하였다. 또한 LCD의 고정세(高情細)화를 위해 Poly Si TFT LCD의 개발이 이루어졌고, 디지타이져 일체형 LCD의 상품화가 그 응용의 폭을 넓혔으며, LCD의 대형화를 위해 1994년 Canon에 의해 14.8', 21' 등의 FLCD가 개발되었다. 대형화 방안으로 Tiled LCD 기술이 개발되고 있으며, 1995년에 Sharp에 의해 21' 두장의 Panel을 이어 붙인 28' TFT LCD가 전시되었고 1996년에는 21' 4장의 Panel을 이어 붙인 40'급 까지의 개발이 시도 되었으며 현재는 LCD의 특성향상과 생산설비의 성능개선과 안정적인 공정관리기술을 바탕으로 삼성전자에서 단패널 40' TFT LCD가 최근에 개발되었다. Projection용 디스플레이로는 Poly-Si TFT LCD를 이용하여 $25'{\sim}100'$사이의 배면투사형과 전면투사형 까지 개발되어 대형 TV시장을 주도하고 있다. 21세기 디지털방송 시대를 맞아 플라즈마디스플레이패널(PDP) TV, 액정표시장치 (LCD)TV, 강유전성액정(FLCD) TV 등 2005년에 약 1500만대 규모의 거대 시장을 형성할 것으로 예상되는 이른바 '벽걸이TV'로 불리는 차세대 초박형 TV 시장을 선점하기 위하여 세계 가전업계들이 양산에 총력을 기울이고 있다. 벽걸이TV 시장이 본격적으로 형성되더라도 PDP TV와 LCD TV가 직접적으로 시장에서 경쟁을 벌이는 일은 별로 없을 것으로 보인다. 향후 디지털TV 시장이 본격적으로 열리면 40인치 이하의 중대형 시장은 LCD TV가 주도하고 40인치 이상 대화면 시장은 PDP TV가 주도할 것으로 보는 시각이 지배적이기 때문이다. 그러나 이러한 직시형 중대형(重大型)디스플레이는 그 가격이 너무 높아서 현재의 브라운관 TV를 대체(代替)하기에는 시일이 많이 소요될 것으로 추정되고 있다. 그 대안(代案)으로는 비교적 저가격(低價格)이면서도 고품질의 디지털 화상구현이 가능한 고해상도 프로젝션 TV가 유력시되고 있다. 이러한 고해상도 프로젝션 TV용으로 DMD(Digital Micro-mirror Display), Poly-Si TFT LCD와 LCOS(Liquid Crystals on Silicon) 등의 상품화가 진행되고 있다. 인터넷과 정보통신 기술의 발달로 휴대형 디스플레이의 시장이 예상 외로 급성장하고 있으며, 요구되는 디스플레이의 품질도 단순한 문자표시에서 그치지 않고 고해상도의 그래픽 동화상 표시와 칼라 표시 및 3차원 화상표시까지 점차로 그 영역이 넓어지고 있다. <표 1>에서 보여주는 바와 같이 LCD의 시장규모는 적용분야 별로 지속적인 성장이 예상되며, 새로운 응용분야의 시장도 성장성을 어느 정도 예측할 수 있다. 따라서 LCD기술의 연구개발 방향은 크게 두가지로 분류할 수 있으며 첫째로는, 현재 양산되고 있는 LCD 상품의 경쟁력강화를 위하여 원가(原價) 절감(節減)과 표시품질을 향상시키는 것이며 둘째로는, 새로운 타입의 LCD를 개발하여 기존 상품을 대체하거나 새로운 시장을 창출하는 분야로 나눌 수 있다. 이와 같은 관점에서 현재 진행되고 있는 LCD기술개발은 다음과 같이 분류할 수 있다. 1) 원가 절감 2) 특성 향상 3) New Type LCD 개발.

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Dynamic Characteristics of Liquidity Filling Materials Mixed with Reclaimed Ash (매립석탄회를 혼합한 유동성 충진재의 동적거동특성)

  • Chae, Deokho;Kim, Kyoungo;Shin, Hyunyoung;Cho, Wanjei
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.4
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    • pp.5-11
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    • 2014
  • Recently, there have been various lifeline installations constructed in the underground space of urban area due to the effective use of land. For newly installed lifelines or the management of the installed lifelines, many construction activities of excavation and backfilling are observed. Around these area, there are possibilities of collapse or excessive settlement due to the leaking of the pipe or unsatisfactory compaction of backfill material. Besides, construction costs can be saved since the on-site soils are used. The application of this liquidity filling material is not only to the lifeline installation but also to underpin the foundation under the vibrating machinery. On the evaluation of the applicability of this method to this circumstance, the strength should be investigated against the static load from the machine load as well as the vibration load from the activation of the machine. In this study, the applicability of the liquidity fill material on the foundation under the vibrating machinery is assessed via uniaxial compression and resonant column tests. The liquidity filling material consisting of the on-site soils with loess and kaolinite are tested to investigate the static and dynamic characteristics. Furthermore, the applicability of the reclaimed ash categorized as an industrial waste is evaluated for the recycle of the waste to the construction materials. The experimental results show that the shear modulus and 7 day uniaxial strength of the liquidity filling material mixed with reclaimed ash show higher than those with the on-site soils. However, the damping ratio does not show any tendency on the mixed materials.

Design and Implementation of Content-based Video Database using an Integrated Video Indexing Method (통합된 비디오 인덱싱 방법을 이용한 내용기반 비디오 데이타베이스의 설계 및 구현)

  • Lee, Tae-Dong;Kim, Min-Koo
    • Journal of KIISE:Computing Practices and Letters
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    • v.7 no.6
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    • pp.661-683
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    • 2001
  • There is a rapid increase in the use of digital video information in recent years, it becomes more important to manage video databases efficiently. The development of high speed data network and digital techniques has emerged new multimedia applications such as internet broadcasting, Video On Demand(VOD) combined with video data processing and computer. Video database should be construct for searching fast, efficient video be extract the accurate feature information of video with more massive and more complex characteristics. Video database are essential differences between video databases and traditional databases. These differences lead to interesting new issues in searching of video, data modeling. So, cause us to consider new generation method of database, efficient retrieval method of video. In this paper, We propose the construction and generation method of the video database based on contents which is able to accumulate the meaningful structure of video and the prior production information. And by the proposed the construction and generation method of the video database implemented the video database which can produce the new contents for the internet broadcasting centralized on the video database. For this production, We proposed the video indexing method which integrates the annotation-based retrieval and the content-based retrieval in order to extract and retrieval the feature information of the video data using the relationship between the meaningful structure and the prior production information on the process of the video parsing and extracting the representative key frame. We can improve the performance of the video contents retrieval, because the integrated video indexing method is using the content-based metadata type represented in the low level of video and the annotation-based metadata type impressed in the high level which is difficult to extract the feature information of the video at he same time.

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The Study on the Embedded Active Device for Ka-Band using the Component Embedding Process (부품 내장 공정을 이용한 5G용 내장형 능동소자에 관한 연구)

  • Jung, Jae-Woong;Park, Se-Hoon;Ryu, Jong-In
    • Journal of the Microelectronics and Packaging Society
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    • v.28 no.3
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    • pp.1-7
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    • 2021
  • In this paper, by embedding a bare-die chip-type drive amplifier into the PCB composed of ABF and FR-4, it implements an embedded active device that can be applied in 28 GHz band modules. The ABF has a dielectric constant of 3.2 and a dielectric loss of 0.016. The FR-4 where the drive amplifier is embedded has a dielectric constant of 3.5 and a dielectric loss of 0.02. The proposed embedded module is processed into two structures, and S-parameter properties are confirmed with measurements. The two process structures are an embedding structure of face-up and an embedding structure of face-down. The fabricated module is measured on a designed test board using Taconic's TLY-5A(dielectric constant : 2.17, dielectric loss : 0.0002). The PCB which embedded into the face-down expected better gain performance due to shorter interconnection-line from the RF pad of the Bear-die chip to the pattern of formed layer. But it is verified that the ground at the bottom of the bear-die chip is grounded Through via, resulting in an oscillation. On the other hand, the face-up structure has a stable gain characteristic of more than 10 dB from 25 GHz to 30 GHz, with a gain of 12.32 dB at the center frequency of 28 GHz. The output characteristics of module embedded into the face-up structure are measured using signal generator and spectrum analyzer. When the input power (Pin) of the signal generator was applied from -10 dBm to 20 dBm, the gain compression point (P1dB) of the embedded module was 20.38 dB. Ultimately, the bare-die chip used in this paper was verified through measurement that the oscillation is improved according to the grounding methods when embedding in a PCB. Thus, the module embedded into the face-up structure will be able to be properly used for communication modules in millimeter wave bands.

Automatic Target Recognition Study using Knowledge Graph and Deep Learning Models for Text and Image data (지식 그래프와 딥러닝 모델 기반 텍스트와 이미지 데이터를 활용한 자동 표적 인식 방법 연구)

  • Kim, Jongmo;Lee, Jeongbin;Jeon, Hocheol;Sohn, Mye
    • Journal of Internet Computing and Services
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    • v.23 no.5
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    • pp.145-154
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    • 2022
  • Automatic Target Recognition (ATR) technology is emerging as a core technology of Future Combat Systems (FCS). Conventional ATR is performed based on IMINT (image information) collected from the SAR sensor, and various image-based deep learning models are used. However, with the development of IT and sensing technology, even though data/information related to ATR is expanding to HUMINT (human information) and SIGINT (signal information), ATR still contains image oriented IMINT data only is being used. In complex and diversified battlefield situations, it is difficult to guarantee high-level ATR accuracy and generalization performance with image data alone. Therefore, we propose a knowledge graph-based ATR method that can utilize image and text data simultaneously in this paper. The main idea of the knowledge graph and deep model-based ATR method is to convert the ATR image and text into graphs according to the characteristics of each data, align it to the knowledge graph, and connect the heterogeneous ATR data through the knowledge graph. In order to convert the ATR image into a graph, an object-tag graph consisting of object tags as nodes is generated from the image by using the pre-trained image object recognition model and the vocabulary of the knowledge graph. On the other hand, the ATR text uses the pre-trained language model, TF-IDF, co-occurrence word graph, and the vocabulary of knowledge graph to generate a word graph composed of nodes with key vocabulary for the ATR. The generated two types of graphs are connected to the knowledge graph using the entity alignment model for improvement of the ATR performance from images and texts. To prove the superiority of the proposed method, 227 documents from web documents and 61,714 RDF triples from dbpedia were collected, and comparison experiments were performed on precision, recall, and f1-score in a perspective of the entity alignment..

A CF-based Health Functional Recommender System using Extended User Similarity Measure (확장된 사용자 유사도를 이용한 CF-기반 건강기능식품 추천 시스템)

  • Sein Hong;Euiju Jeong;Jaekyeong Kim
    • Journal of Intelligence and Information Systems
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    • v.29 no.3
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    • pp.1-17
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    • 2023
  • With the recent rapid development of ICT(Information and Communication Technology) and the popularization of digital devices, the size of the online market continues to grow. As a result, we live in a flood of information. Thus, customers are facing information overload problems that require a lot of time and money to select products. Therefore, a personalized recommender system has become an essential methodology to address such issues. Collaborative Filtering(CF) is the most widely used recommender system. Traditional recommender systems mainly utilize quantitative data such as rating values, resulting in poor recommendation accuracy. Quantitative data cannot fully reflect the user's preference. To solve such a problem, studies that reflect qualitative data, such as review contents, are being actively conducted these days. To quantify user review contents, text mining was used in this study. The general CF consists of the following three steps: user-item matrix generation, Top-N neighborhood group search, and Top-K recommendation list generation. In this study, we propose a recommendation algorithm that applies an extended similarity measure, which utilize quantified review contents in addition to user rating values. After calculating review similarity by applying TF-IDF, Word2Vec, and Doc2Vec techniques to review content, extended similarity is created by combining user rating similarity and quantified review contents. To verify this, we used user ratings and review data from the e-commerce site Amazon's "Health and Personal Care". The proposed recommendation model using extended similarity measure showed superior performance to the traditional recommendation model using only user rating value-based similarity measure. In addition, among the various text mining techniques, the similarity obtained using the TF-IDF technique showed the best performance when used in the neighbor group search and recommendation list generation step.