• Title/Summary/Keyword: Frequency Domain Analysis

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Research Trends in English-Language Journals of Korean Studies Published in Korea (국내에서 간행된 한국학 분야 영문학술지의 연구 동향 분석)

  • Min Jung, Kim;Hye-Eun, Lee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.34 no.1
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    • pp.145-166
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    • 2023
  • This study aims to analyze the research trends of English-language journals in Korean studies published in Korea. Data were collected from four English journals in Korean studies indexed in A&HCI and SCOPUS. A total of 1,840 were selected, including 768 articles of the Korea Journal, 466 articles of The Review of Korean Studies, 285 articles of the Seoul Journal of Korean Studies, and 321 articles of the Acta Koreana, in connection with content analysis, author analysis, author keyword frequency analysis, and topic modeling. In results, the domain research of Korean studies is Humanities, followed by Social Science, and Arts and Kinesiology. These three sectors have grown significantly in publishing numbers since 2000. The subject period of the study is in the order of the modern period, late Joseon, and Japanese colonial period. Authors from domestic affiliations made up 73.34% of the total, but the proportion of authors belonging to foreign institutions continued to increase. As for author keywords, 'Korea'(41), 'Buddhism'(20), 'Koreanwar'(18), and 'Joseon'(18) were derived as top keywords. In topic modeling, six topics were identified; 'Korean culture, cultural transmission,' 'Korean modern political history,' 'Korean social democratization process,' 'Japanese colonial period,' 'Korean religious philosophy,' and 'Korean ancient history.' Through this study, it was possible to identify the interests in and research areas of the recent international academic community of Korean studies.

Seismic analysis and dynamic behavior characterization of rib-reinforced pre-cast tunnels (리브 보강 프리캐스트 터널의 내진 해석 및 동적거동 특성 파악)

  • Song, Ki-Il;Jung, Sung-Hoon;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.287-301
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    • 2009
  • The novel cut-and-cover tunnel construction method using rib-reinforced pre-cast arch segments has been recently developed and applied for practice to secure a structural stability of high covering and wide width section tunnels. Cut-and-cover tunnels are usually damaged by the seismic behavior of backfill grounds in case of a low covering condition. Seismic analyses are performed in this study to characterize the dynamic behavior of rib-reinforced pre-cast arch cut-and-cover tunnels. Seismic analyzes for 2 lane cast-in-place and rib-reinforced pre-cast arch cut-and-cover tunnels are carried out by using the commercial FDM program (FLAC2D) considering various field conditions such as the covering height embankment slope and excavation slope. It can be concluded that the amplification of seismic wave is reduced due to an increase in the structural stiffness induced by rib-reinforcement. The results show that the rib-reinforced pre-cast arch cut-and-cover tunnels are more effective against the seismic loading, compared to the cast-in-place cut-and-cover tunnels.

A Study on the Prediction Method of Information Exchange Requirement in the Tactical Network (전술네트워크의 정보교환요구량 예측 방법에 관한 연구)

  • Pokki Park;Sangjun Park;Sunghwan Cho;Junseob Kim;Yongchul Kim
    • Convergence Security Journal
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    • v.22 no.5
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    • pp.95-105
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    • 2022
  • The Army, Navy, and Air Force are making various efforts to develop a weapon system that incorporates the 4th industrial revolution technology so that it can be used in multi-domain operations. In order to effectively demonstrate the integrated combat power through the weapon system to which the new technology is applied, it is necessary to establish a network environment in which each weapon system can transmit and receive information smoothly. For this, it is essential to analyze the Information Exchange Requirement(IER) of each weapon system, but many IER analysis studies did not sufficiently reflect the various considerations of the actual tactical network. Therefore, this study closely analyzes the research methods and results of the existing information exchange requirements analysis studies. In IER analysis, the size of the message itself, the size of the network protocol header, the transmission/reception structure of the tactical network, the information distribution process, and the message occurrence frequency. In order to be able to use it for future IER prediction, we present a technique for calculating the information exchange requirement as a probability distribution using the Poisson distribution and the probability generating function. In order to prove the validity of this technique, the results of the probability distribution calculation using the message list and network topology samples are compared with the simulation results using Network Simulator 2.

Construction and estimation of soil moisture site with FDR and COSMIC-ray (SM-FC) sensors for calibration/validation of satellite-based and COSMIC-ray soil moisture products in Sungkyunkwan university, South Korea (위성 토양수분 데이터 및 COSMIC-ray 데이터 보정/검증을 위한 성균관대학교 내 FDR 센서 토양수분 측정 연구(SM-FC) 및 데이터 분석)

  • Kim, Hyunglok;Sunwoo, Wooyeon;Kim, Seongkyun;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.49 no.2
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    • pp.133-144
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    • 2016
  • In this study, Frequency Domain Reflectometry (FDR) and COSMIC-ray soil moisture (SM) stations were installed at Sungkyunkwan University in Suwon, South Korea. To provide reliable information about SM, soil property test, time series analysis of measured soil moisture, and comparison of measured SM with satellite-based SM product are conducted. In 2014, six FDR stations were set up for obtaining SM. Each of the stations had four FDR sensors with soil depth from 5 cm to 40 cm at 5~10 cm different intervals. The result showed that study region had heterogeneous soil layer properties such as sand and loamy sand. The measured SM data showed strong coupling with precipitation. Furthermore, they had a high correlation coefficient and a low root mean square deviation (RMSD) as compared to the satellite-based SM products. After verifying the accuracy of the data in 2014, four FDR stations and one COSMIC-ray station were additionally installed to establish the Soil Moisture site with FDR and COSMIC-ray, called SM-FC. COSMIC-ray-based SM had a high correlation coefficient of 0.95 compared with mean SM of FDR stations. From these results, the SM-FC will give a valuable insight for researchers into investigate satellite- and model-based SM validation study in South Korea.

Needs on Management Development Program for Head Nurse (간호 관리 능력 개발을 위한 교육 연구)

  • Park, Jeong-Sun
    • Journal of Home Health Care Nursing
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    • v.5
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    • pp.84-99
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    • 1998
  • The objectives of this study are to identify the actual educational contents of management for head nurse and to propose the educational subjects according to identity the needs of head, charge, and staff nurses. The subjects were investigated the actual Management Development Programs and educational needs of head nurses and prospective nurse manager(charge nurse, staff nurse with a lot of clinical experiences) in general hospitals. The tools were composed of two questionnaires: One was developed from the literature review for making items to measure actual situation. The other was revised Katz's model for measurement of educational needs. The first respondents of actual situation were 27 general hospitals with over 400 beds in Seoul and the second respondents were 89 head nurses, 67 charge nurses and 136 nurses at 3 hospitals by convenient sampling out of 27 general hospitals. Data were collected by telephone interview, mail questionnaire and visiting from 7th of October through 30th of November in 1997. In data analysis, general characteristics of the respondents and actual status of Management Development Programs were analyzed by frequency and percentage. Educational needs according to general characteristics were analyzed by ANOVA The results were as follows: 1. Actual situation of Management Development Program 1) Seven hospitals(26%) had Management Development Program for prospective managers and 14 hospitals (52%) for head nurses. 2) Education Department existed in 14 hospitals (52%). 3) One hospital(4%) had top level managers took part in the Management Development. 4) Two hospitals selected head nurse, who had finished courses of Management Development. Eight hospitals(30%) assessed educational needs. The assessment tools consisted of making a question via questionnaire(75%), determining at department meeting(12%) and interview(13%). 5) Educational programs had 3 types: 10 lecture type, 7 discussion type and 4 role play type programs. 6) One hospital evaluated the change of learner's attitude. 7) Four hospitals scored educational point, but that was measured only by attending. 8) Actual Management Development Programs were as follows. parenthesis indicates the number of hospitals. (1) Management Development Programs for Prospective manager. Role perception of Middle level Manager (1) . Role reconstruction of Nurse Manager (1). Workshop for Charge Nurse (1). Nursing Delivery System and Nursing Process (1). Communication (1). Motivation (1) (2) Management Development Programs for Head nurse.. Head nurse's Role (5). Administrative Work (7). Service Education (4). Prevention and Countermeasure of Nursing Incidence (3). Appraisal (3) 2. The results of needs on Management Development subject 1) The educational needs of all respondents on 3 skill domains showed positive agreement to strongly positive agreement. 2) High priority(more than 4.5) items were 12 of 24 Human skill items(50%), 1 of 6 Technical skill items(16%), and 2 of 13 Conceptual skill items (15%). 3) Out of high priority items, 8 items were instituted. 4) All respondents showed high needs on 3 skill domains regardless of 3 positions (head nurse, charge nurse, and nurse). Educational needs of Human skill domain, according to position were 108. S, 108.7, 106.8 (mean score = 72) , needs of Technical skill domain were 26.5, 26.6, 26.I(mean score=18), and needs of Conceptual skill domains were 56.9,56.7, 55.1(mean score=39). 5) Needs of 3 skill domains according to clinical career showed significant difference. Out of respondents, nurses with career of over 16years showed lowest degree of needs in Human skill domains(F=4.47, P=.004) and Conceptual skill domain(F=2.93, P=.034). 6) Educational needs according to educational background were not significant difference. But out of respondents, nurses educated at 3-year junior college relatively showed lowest needs in all of the 3 skill domains. With the above-mentioned findings, further study is necessary for generalization of this study at hospitals with different bed size and location. Also it is needed to study about management skill of nurse and charge nurse, and effective educational method.

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Fragility Analysis Method Based on Seismic Performance of Bridge Structure considering Earthquake Frequencies (지진 진동수에 따른 교량의 내진성능기반 취약도 해석 방법)

  • Lee, Dae-Hyoung;Chung, Young-Soo;Yang, Dong-Wook
    • Journal of the Korea Concrete Institute
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    • v.21 no.2
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    • pp.187-197
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    • 2009
  • This paper presents a systematic approach for estimating fragility curves and damage probability matrices for different frequencies. Fragility curves and damage probability indicate the probabilities that a structure will sustain different degrees of damage at different ground motion levels. The seismic damages are to achieved by probabilistic evaluation because of uncertainty of earthquakes. In contrast to previous approaches, this paper presents a method that is based on nonlinear dynamic analysis of the structure using empirical data. This paper presents the probability of damage as a function of peak ground acceleration and estimates the probability of five damage levels for prestressed concrete (PSC) bridge pier subjected to given ground acceleration. At each level, 100 artificial earthquake motions were generated in terms of soil conditions, and nonlinear time domain analyses was performed for the damage states of PSC bridge pier structures. These damage states are described by displacement ductility resulting from seismic performance based on existing research results. Using the damage states and ground motion parameters, five fragility curves for PSC bridge pier with five types of dominant frequencies were constructed assuming a log-normal distribution. The effect of dominant frequences was found to be significant on fragility curves.

Buffeting Response Correction Method based on Dynamic Properties of Existing Cable-Stayed Bridge (공용 사장교의 동적특성을 반영하는 버페팅 응답보정법)

  • Kim, Byeong Cheol;Yhim, Sung Soon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.71-80
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    • 2013
  • According to design specifications for structural safety, a bridge in initial design step has been modelled to have larger self-weight, external loads and less stiffness than those of real one in service. Thereby measured buffeting responses of existing bridge show different distributions from those of the design model in design step. In order to obtain accurate buffeting responses of the in-site bridge, the analysis model needs to be modified by considering the measured natural frequencies. Until now, a Manual Tuning Method (MTM) has been widely used to obtain the Measurement-based Model(MBM) that has equal natural frequencies to the real bridge. However, since state variables can be selected randomly and its result is not apt to converge exact rapidly, MTM takes a lot of effort and elapsed time. This study presents Buffeting Response Correction Method (BRCM) to obtain more exact buffeting response above MTM. The BRCM is based on the idea the commonly used frequency domain buffeting analysis does not need all structural properties except mode shapes, natural frequencies and damping ratio. BRCM is used to improve each modal buffeting responses of the design model by substituting measured natural frequencies. The measured natural frequencies are determined from acceleration time-history in ordinary vibration of the real bridge. As illustrated examples, simple beam is applied to compare the results of BRCM with those of a assumed MBM by numerical simulation. Buffeting responses of BRCM are shown to be appropriate for those of in-site bridge and the difference is less than 3% between the responses of BRCM and MTM. Therefore, BRCM can calculate easily and conveniently the buffeting responses and improve effectively maintenance and management of in-site bridge than MTM.

Geometric analysis and anti-aliasing filter for stereoscopic 3D image scaling (스테레오 3D 영상 스케일링에 대한 기하학적 분석 및 anti-aliasing 필터)

  • Kim, Wook-Joong;Hur, Nam-Ho;Kim, Jin-Woong
    • Journal of Broadcast Engineering
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    • v.14 no.5
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    • pp.638-649
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    • 2009
  • Image resizing (or scaling) is one of the most essential issues for the success of visual service because image data has to be adapted to the variety of display features. For 2D imaging, the image scaling is generally accomplished by 2D image re-sampling (i.e., up-/down-sampling). However, when it comes to stereoscopic 3D images, 2D re-sampling methods are inadequate because additional consideration on the third dimension of depth is not incorporated. Practically, stereoscopic 3D image scaling is process with left/right images, not stereoscopic 3D image itself, because the left/right Images are only tangible data. In this paper, we analyze stereoscopic 3D image scaling from two aspects: geometrical deformation and frequency-domain aliasing. A number of 3D displays are available in the market and they have various screen dimensions. As we have more varieties of the displays, efficient stereoscopic 3D image scaling is becoming more emphasized. We present the recommendations for the 3D scaling from the geometric analysis and propose a disparity-adaptive filter for anti-aliasing which could occur during the image scaling process.

Online Information Sources of Coronavirus Using Webometric Big Data (코로나19 사태와 온라인 정보의 다양성 연구 - 빅데이터를 활용한 글로벌 접근법)

  • Park, Han Woo;Kim, Ji-Eun;Zhu, Yu-Peng
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.728-739
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    • 2020
  • Using webometric big data, this study examines the diversity of online information sources about the novel coronavirus causing the COVID-19 pandemic. Specifically, it focuses on some 28 countries where confirmed coronavirus cases occurred in February 2020. In the results, the online visibility of Australia, Canada, and Italy was the highest, based on their producing the most relevant information. There was a statistically significant correlation between the hit counts per country and the frequency of visiting the domains that act as information channels. Interestingly, Japan, China, and Singapore, which had a large number of confirmed cases at that time, were providing web data related to the novel coronavirus. Online sources were classified using an N-tuple helix model. The results showed that government agencies were the largest supplier of coronavirus information in cyberspace. Furthermore, the two-mode network technique revealed that media companies, university hospitals, and public healthcare centers had taken a positive attitude towards online circulation of coronavirus research and epidemic prevention information. However, semantic network analysis showed that health, school, home, and public had high centrality values. This means that people were concerned not only about personal prevention rules caused by the coronavirus outbreak, but also about response plans caused by life inconveniences and operational obstacles.

Application of Terahertz Spectroscopy and Imaging in the Diagnosis of Prostate Cancer

  • Zhang, Ping;Zhong, Shuncong;Zhang, Junxi;Ding, Jian;Liu, Zhenxiang;Huang, Yi;Zhou, Ning;Nsengiyumva, Walter;Zhang, Tianfu
    • Current Optics and Photonics
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    • v.4 no.1
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    • pp.31-43
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    • 2020
  • The feasibility of the application of terahertz electromagnetic waves in the diagnosis of prostate cancer was examined. Four samples of incomplete cancerous prostatic paraffin-embedded tissues were examined using terahertz spectral imaging (TPI) system and the results obtained by comparing the absorption coefficient and refractive index of prostate tumor, normal prostate tissue and smooth muscle from one of the paraffin tissue masses examined were reported. Three hundred and sixty cases of absorption coefficients from one of the paraffin tissues examined were used as raw data to classify these three tissues using the Principal Component Analysis (PCA) and Least Squares Support Vector Machine (LS-SVM). An excellent classification with an accuracy of 92.22% in the prediction set was achieved. Using the distribution information of THz reflection signal intensity from sample surface and absorption coefficient of the sample, an attempt was made to use the TPI system to identify the boundaries of the different tissues involved (prostate tumors, normal and smooth muscles). The location of three identified regions in the terahertz images (frequency domain slice absorption coefficient imaging, 1.2 THz) were compared with those obtained from the histopathologic examination. The tissue tumor region had a distinctively visible color and could well be distinguished from other tissue regions in terahertz images. Results indicate that a THz spectroscopy imaging system can be efficiently used in conjunction with the proposed advanced computer-based mathematical analysis method to identify tumor regions in the paraffin tissue mass of prostate cancer.