• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.375-378
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• 2014

세월호 사건으로 인하여, 선박에서 발생하는 통신에 대한 육지와 구난 시스템과의 통신 연계가 문제 되고 있다. 또한 3면이 바다로 되어 있는 우리나라의 입장에서는 해상 구난과 비상 재난을 위한 연계 통신 시스템에 대한 점검이 필요해졌다. 해상에서 항해하는 선박은 단독으로 재난을 처리해야 하므로 연계 통신 시스템이 보다 완전하게 갖추어 져야 한다. 더불어 해상에서 침수되어 침몰하는 선박뿐만 아니라, 해저로 운항하는 잠수함에 대한 연계 통신에 대한 연구가 필요하다. 그리고 육지에서는 해상과 해저의 선박 및 잠수함의 비상 재난에 대비한 유상 연계 통신과 연계 통신 시스템에 대한 연구가 필요하다. 이를 통해 통신 프로토콜과 비상 재난을 대비한 위치 확인 및 육상과 통산을 위한 비행기나 인공위성과의 연계 시스템도 연구되어져야 할 것이다. 이를 위해 통합된 비상재난 통신 연계 시스템에 대한 연구가 필요하다.

• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.305-316
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• 2022

Numerous research revealed a strong association between the ionospheric perturbations and various natural hazards. The ionospheric measurements from Global Navigation Satellite System (GNSS) observations provide the state of electron contents in the ionosphere that contributes to investigate the source events. In this study, two geophysical events occurred on 23 January 2018, the 7.9 Mw earthquake in Alaska and Kusatsu-Shiranesan volcanic eruption in Japan, are examined to characterize the fingerprint of each event in the ionosphere. Firstly, we extracted the Total Electron Content (TEC) from GNSS measurements, then isolated disturbed wave signatures from the TEC measurements that is referred to as a traveling ionospheric disturbance (TID). As TIDs are short-term ionospheric variations, the major trend of GNSS TEC measurements should be properly removed. We applied a natural neighbor interpolation method together with a leave-one-out cross validation technique for detrending. After detrending the TEC, the remaining signals are further enhanced by applying a band-pass filter and TIDs are detected from them. Finally, the detected TIDs are verified as the response of the ionosphere to Kusatsu-Shiranesan volcanic eruption and Gulf of Alaska earthquake which propagated through the ionosphere with an average velocity of 530 m/s and 724 m/s, respectively. In addition, a coherence analysis is conducted to discriminate between the signatures from a volcanic explosion and an earthquake. The analysis reveals the TID waveforms from each single event are highly correlated, while a low correlation is found between the TIDs from the earthquake and explosion. This study supports the claim that different geophysical events induce the distinctive characteristics of TIDs that are detectable by the ionospheric measurements of GNSS.

• 한국농공학회논문집
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• 제63권4호
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• pp.23-32
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• 2021

For agricultural water management, it is essential to establish the digital infrastructure data such as agricultural watershed, irrigated area and canal network in rural areas. Approximately 70,000 irrigation facilities in agricultural watershed, including reservoirs, pumping and draining stations, weirs, and tube wells have been installed in South Korea to enable the efficient management of agricultural water. The total length of irrigation and drainage canal network, important components of agricultural water supply, is 184,000 km. Major problem faced by irrigation facilities management is that these facilities are spread over an irrigated area at a low density and are difficult to access. In addition, the management of irrigation facilities suffers from missing or errors of spatial information and acquisition of limited range of data through direct survey. Therefore, it is necessary to establish and redefine accurate identification of irrigated areas and canal network using up-to-date high resolution images. In this study, previous existing data such as RIMS (Rural Infrastructure Management System), smart farm map, and land cover map were used to redefine irrigated area and canal network based on appropriate image data using satellite imagery, aerial imagery, and drone imagery. The results of the building the digital infrastructure in rural areas are expected to be utilized for efficient water allocation and planning, such as identifying areas of water shortage and monitoring spatiotemporal distribution of water supply by irrigated areas and irrigation canal network.

• 대기
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• 제33권2호
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• pp.173-195
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• 2023

Research papers in the field of atmospheric environment published in three Journals: Journal of Korean Meteorological Society, Atmosphere, and Asia-Pacific Journal of the Atmospheric Sciences, are all summarized over period of 60 years since the establishment of Korea Meteorological Society (KMS) in 1963. In addition, current research trends and future outlook in the atmospheric environment field has been also highlighted. The results of historical records published in three KMS journals indicated that the activities, contents, and scope of researches carried out by KMS members in the field of atmospheric environment have yielded the enormous and rapid progress in each of the all four areas over 60 years. In particular, as the chronological progress of observational instruments and availability of satellite data such as from GEMS can be a great asset to deepen the observational and modeling researches in the current and future studies, it is highly anticipated that the more progressive and in-depth studies can be achievable to abate the air pollutants over the Korea as well as northeast Asia.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.245-251
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• 2022

In this paper, a high gain, broadband planar vivaldi antenna (PVA) by utilizing a broadband stripline feed is developed for wireless communication for IoT systems. The suggested antenna is designed by attaching a tapered-slot construction to a typical vivaldi antenna, which improves the antenna's radiation properties. The PVA is constructed on a low-cost FR4 substrate. The dimensions of the patch are 1.886λ₀×1.42λ₀×0.026λ₀, dielectric constant Ɛ_r=4.4, and loss tangent δ=0.02. The width of the feed line is reduced to improve the impedance bandwidth of the antenna. The computed reflection coefficient findings show that the suggested antenna has a 46.2% wider relative bandwidth calculated at a 10 dB return loss. At the resonance frequencies of 6.5 GHz, the studied results show an optimal gain of 5.82 dBi and 85% optimal radiation efficiency at the operable band. The optometric analysis of the proposed structure shows that the proposed antenna can achieve wide enough bandwidth at the desired frequency and hence make the designed antenna appropriate to work in satellite communication and medical internet of things (M-IoT) healthcare applications.

• Journal of Animal Science and Technology
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• 제51권5호
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• pp.413-420
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• 2009

본 연구는 성체우의 FS, MS, C-MS를 배양액에 첨가하여 세포증식과 난포의 성장과 배란에 미치는 영향을 관찰하기 위하여 실시하였다. 세포증식은 세포수와 MTT assay을 실시하여 확인하였다. 그 결과 세포증식은 혈청첨가 배양액에 따라 유의적인 차이를 나타내었다. 특히 근육위성세포의 세포증식은 MS를 첨가한 배양액에서 높은 반면 면역세포의 증식은 FBS에서 배양한 세포에 비해 낮은 것을 확인하였다. 또한 난포의 성장 및 배란을 관찰한 결과 난포의 성장에 유의한 차이가 없었으나 군간 차이를 보였으며 배란율과 비례적이었고, 배란율은 FBS와 C-MS가 첨가된 배양액에서 유의적으로 높은 것을 관찰할 수 있었다(P<0.05). FBS군과 C-MS 군 간에는 차이가 없었다. 3T3-L1 세포에서 창상치유는 FS에서 배양한 세포에서 빠른 회복을 나타냈으며, 증식은 MS에서 높게 나타났다(p<0.001). 따라서 본 결과는 세포배양 과정에서 세포에 따른 혈청의 선택은 매우 중요하다는 근거자료를 제시 하였으며, 분리 된 성별 특이 한우 혈청은 FBS의 대체 물질로서 사용이 가능할 것으로 사료된다.

• 대기
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• 제31권1호
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• pp.113-141
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• 2021

The impacts of ice clouds on the energy budget of the Earth and their representation in climate models have been identified as important and unsolved problems. Ice clouds consist almost exclusively of non-spherical ice crystals with various shapes and sizes. To determine the influences of ice clouds on solar and infrared radiation as required for remote sensing retrievals and numerical models, knowledge of scattering and microphysical properties of ice crystals is required. A conventional method for representing the radiative properties of ice clouds in satellite retrieval algorithms and numerical models is to combine measured microphysical properties of ice crystals from field campaigns and pre-calculated single-scattering libraries of different shapes and sizes of ice crystals, which depend heavily on microphysical and scattering properties of ice crystals. However, large discrepancies between theoretical calculations and observations of the radiative properties of ice clouds have been reported. Electron microscopy images of ice crystals grown in laboratories and captured by balloons show varying degrees of complex morphologies in sub-micron (e.g., surface roughness) and super-micron (e.g., inhomogeneous internal and external structures) scales that may cause these discrepancies. In this study, the current idealized models representing morphologies of ice crystals and the corresponding numerical methods (e.g., geometric optics, discrete dipole approximation, T-matrix, etc.) to calculate the single-scattering properties of ice crystals are reviewed. Current problems and difficulties in the calculations of the single-scattering properties of atmospheric ice crystals are addressed in terms of cloud microphysics. Future directions to develop physically consistent ice-crystal models are also discussed.

• 한국지리정보학회지
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• 제22권4호
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• pp.116-130
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• 2019

우리나라는 산림 내 연료 물질 증가와 기후변화 등의 요인으로 산불의 연중화와 대형화가 증가하는 추세에 있으므로 산불 발생 확률에 대한 정보를 제공함으로써 산불 발생을 예방하여 피해를 최소화할 필요성이 대두되고 있다. 본 연구에서는 현 산불예보시스템에서 제공하는 산불위험지수(DWI; Daily Weather Index)를 개선하기 위한 방법을 살펴보았다. 즉, 우리나라 산불위험지수의 시간 및 공간적 정확성 향상을 통한 고도화를 목적으로, 기상청에서 제공하는 동네예보 자료, 위성기반의 가뭄 지수, 산불 다발 지역 지도를 융합하여 5km 격자 형태로 제공되는 새로운 산불위험지수(FRI; Fire Risk Index)를 제안하였다. 산불위험지수는 캐나다에서 현업으로 사용되는 미세 연료 지수를 기반으로 우리나라에 최적화한 미세 연료 지수, 가뭄지수의 곱과 시간 및 공간적 가중치를 통하여 산출된다. 시간적인 정확성 향상을 위하여 산림청에서 제공하는 산불 피해 대장 표를 이용하여 월별 산불 통계량을 통한 월별 가중치를 적용하였으며, 공간적인 정확성 향상을 위하여 산불 다발 지역 지도의 산불 밀도 정보를 이용하여 가중치를 적용하였다. 월별 산불 발생 건수와 제안된 산불위험지수의 시계열을 분석하였을 때 증가 및 감소 경향을 잘 모의하고 있었으며, 5km 격자 형태로 산불위험지수를 제공함으로써 행정 구역 단위로 산불위험지수를 제공할 때보다 상세한 정보를 제공할 수 있었으므로 지역적으로 더욱 정확하고 구체적인 산불 예방에 대한 의사 결정에 도움이 될 것으로 기대된다.

• 가정과삶의질연구
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• 제4권1호
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• pp.1-13
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• 1986

The purpose of this study was to examine whether the Marital Satisfaction Scale(M.S.S) is properly applicable to Korean couples and further to be devoted to the designed of a marital satisfaction scale for Korea. The scale employed in this study was a Korean adaptation of the M.S.S., which originally included 73 items but was reduced to 48 through a study of its validity by Bowden. This scale was administered to 420 couples. One kindergarten, two elementary schools, one middle school, and four high schools, all of them located in Seoul or its satellite cities were selected for the present study. The results of the study were as follows. 1) Through item analysis, 85.4% of the total items showed a high index of discrimination, i.e, of more than +.40, which all was significant discrimination (P<0.001) excluding two items. 2)Factor analysis, which was oriented toward combining factors proper to theory, showed that the M.S.S. consisted of 6 factors and its total variance was 50.18%. The 6 factors were marital satisfaction (factor 1), marital social psychological companionship (factor 2), obstacles to marriage (factor 3), dissatisfaction of marital relationship (factor 4), attitude of the reasonable marital relationship (factor 5), and cognition of married life (factor 6), 3) internal consistency reliability of the M.S.S. was 0.951 and the reliability of the total items after excluding two through item analysis 0.956 and 0.949 respectively, which showed a high internal consistency 4) The marital satisfaction examined by the M.S.S showed significant differences according to sex, education , income, the duration of marriage, the number of children but no significant differences according to age, and family type. From these results, it will be concluded that the M.S.S is a reliable and valid psychological scale for examining marital satisfaction of Korean couples. The limitations of this study were as follows. 1) It can not be generalized to all Korean couples because the subjects was sampled from Seoul or satellite cities. 2)The factor analysis in this study was oriented toward combining factors proper to theory. However, it was very difficult to find out the factors because the components of the M.S.S. was more or less abstract. Thus, from these results some suggestions follow for developing the marital satisfaction scale proper to Korean couples systematically and scientifically. 1) The subjects must be sampled form urban as well as rural areas 2)Factor analysis in this study is oriented toward finding out factors of the M.S.S. Thus, it is needed to analyze the factor validity or construct validity by multitrait - multimethod of the scale with more theoretical conceptualization. 3) It is necessary to examine whether marital satisfaction shows difference according to couples and psychological variables besides objective demographic variables. 4) More research is needed before the M.S.S. con be adapted into a turely useful marital satisfaction scale for Korea.

• 한국지구과학회지
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• 제33권7호
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• pp.645-657
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• 2012

이 연구의 목적은 초등교사가 될 교대 신입생들의 우주와 은하 그리고 현행 초등 과학과 교과서에 등장하는 주요 천체들(별, 행성, 위성, 소행성, 혜성)의 상대적 크기에 대한 인식을 조사하고, 이들이 가지고 있는 천체의 상대적 크기에 대한 오개념의 원인을 밝히는 것이다. 이를 위해 63명의 예비교사가 이 연구에 참여하였으며, 이들은 연구자들이 개발한 설문지에 제시된 문항, 즉 제시된 천체들을 그 상대적 크기 순서로 나열하고 각 천체들의 대한 설명의 글을 작성하도록 하는 문항에 응답을 하였다. 이들의 응답은 양적 분석과 응답자의 기술에 근거한 질적 분석을 통해 분석되었으며, 이에 대한 구체적인 연구 결과는 다음과 같다: 첫째, '우주>은하>별>행성>위성>소행성>혜성'이라고 제시된 천체들에 대해 바르게 나열한 교사는 총 63명 중 5명(7.9%), '우주>은하>별>행성'까지 바르게 나열한 예비교사도 28명(44.4%)에 불과하였다. 둘째, 천체들의 상대적 크기에 대한 예비교사들의 두드러진 주요 오개념은, '행성이 별보다 크다(행성>별, 29명, 46.0%)', '소행성이 위성보다 크다'(소행성>위성, 37명, 58.7%) '혜성이 별보다 크다(혜성>별, 14명, 22.2%)'는 것이다.