• Title/Summary/Keyword: Observation frequency

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Evaluating of the Effectiveness of RTK Surveying Performance Based on Low-cost Multi-Channel GNSS Positioning Modules (다채널 저가 GNSS 측위 모듈기반 RTK 측량의 효용성 평가)

  • Kim, Chi-Hun;Oh, Seong-Jong;Lee, Yong-Chang
    • Journal of Cadastre & Land InformatiX
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    • v.52 no.2
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    • pp.53-65
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    • 2022
  • According to the advancement of the GNSS satellite positioning system, the module of hardware and operation software reflecting accuracy and economical efficiency is implemented in the user sector including the multi-channel GNSS receiver, the multi-frequency external antenna and the mobile app (App) base public positioning analysis software etc., and the multichannel GNSS RTK positioning of the active configuration method (DIY, Do it yourself) is possible according to the purpose of user. Especially, as the infrastructure of multi-GNSS satellite is expanded and the potential of expansion of utilization according to various modules is highlighted, interest in the utilization of multi-channel low-cost GNSS receiver module is gradually increasing. The purpose of this study is to review the multi-channel low-cost GNSS receivers that are appearing in the mass market in various forms and to analyze the utilization plan of the "address information facility investigation project" of the Ministry of Public Administration and Security by constructing the multi-channel low-cost GNSS positioning module based RTK survey system (hereinafter referred to as "multi-channel GNSS RTK module positioning system"). For this purpose, we constructed a low-cost "multi-channel GNSS RTK module positioning system" by combining related modules such as U-blox's F9P chipset, antenna, Ntrip transmission of GNSS observation data and RTK positioning analysis app through smartphone. Kinematic positioning was performed for circular trajectories, and static positioning was performed for address information facilities. The results of comparative analysis with the Static positioning performance of the geodetic receivers were obtained with 5 fixed points in the experimental site, and the good static surveying performance was obtained with the standard deviation of average ±1.2cm. In addition, the results of the test point for the outline of the circular structure in the orthogonal image composed of the drone image analysis and the Kinematic positioning trajectory of the low cost RTK GNSS receiver showed that the trajectory was very close to the standard deviation of average ±2.5cm. Especially, as a result of applying it to address information facilities, it was possible to verify the utility of spatial information construction at low cost compared to expensive commercial geodetic receivers, so it is expected that various utilization of "multi-channel GNSS RTK module positioning system"

A Study on Changes of Symptoms and Signs Diagnosised by Differentiation of the Pattern Identification in Acute Ischemic Stroke Patients with Collaborative Treatment (한·양방 병행치료를 시행한급성기 뇌경색 환자에게 변증(辨證)별 평가항목 호전도에 대한 연구)

  • Lu, Hsu-yuan;Kim, Soo-kyung;Shim, So-ra;Kim, Hye-mi;Park, Joo-young;Cho, Seung-yeon;Park, Seong-uk;Jung, Woo-sang;Moon, Sang-kwan;Park, Jung-mi;Ko, Chang-nam;Cho, Ki-ho;Kim, Young-suk;Bae, Hyung-sup
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.12 no.1
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    • pp.16-23
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    • 2011
  • Object : The purpose of this study is to observe the changes of symptoms and signs diagnosised by differentiation of the pattern identification in stroke patients. Methods : Seventy subjects were recruited from patients with stroke within ten days of onset. We chose twenty-nine subjects diagnosised as same differentiation of the pattern identification, and who had at least on follow up session. We had investigated change of symptoms and signs diagnosised by differentiation of the pattern identification. Results : There were five symptoms and signs (thick fur, dry fur, difficult defecation, heat vexation and aversion to heat, normal pulse) and ten (heavy-headedness, frequency of defecation, hard defecation, feel heavy, slippery pulsem, dry mouth, bitter taste in the mouth, feel lazy, look lazy) symptoms and signs that were statistically significant improved in fire-heat patterns and dampness-phlegm pattern, respectively. Conclusions : This study provides evidence that collaborative treatment is effective in improving some symptoms and signs in acute ischemic stroke patients diagnosised by fire-heat pattern and dampness-phlegm pattern. Further studies with larger scale, longer observation period would be required.

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Current Status and Actual Conditions of the Use of Occupational Therapy Evaluation Tools in Relation to the Type of Therapy Institution (국내 아동작업치료 기관별 평가도구 사용 현황 및 실태에 관한 연구)

  • Gil, Young-Suk;Yoo, Doo-Han
    • The Journal of Korean Academy of Sensory Integration
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    • v.21 no.1
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    • pp.47-58
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    • 2023
  • Objective : This study aimed to investigate the current status and actual use of assessment tools by institutions in the field of occupational therapy with children in Korea. Methods : The study was conducted with 67 occupational therapists working with children in Korea. To investigate the use of evaluation tools by area, knowledge of the evaluation tools, and desire to participate in further education, the questionnaires used in studies by Lee, Hong, and Park (2018) and Kim (2015) were modified and supplemented according to the child evaluation tools currently in usein institutions in Korea. For data collection, we distributed Google questionnaires to child occupational therapists for 3 weeks using convenience sampling. Excel was used to analyze the use of the evaluation tools according to institution. Technical statistics and frequency analyses were used to verify the general characteristics, evaluation-related information, status of evaluation tool use, knowledge levels relating to evaluation tools, and desire to participate in education. A t-test was used for the evaluation tool status. Results : Welfare centers used the most evaluation tools, with an average of 11.1, followed by university hospitals, rehabilitation hospitals, clinics, and daycare centers. There were differences in the choice of tools used, hospital with the Jebsen-Taylor hand function test and the Wee-FIM (Functional Independence Measure) being the most frequently applied. Centers, daycare centers, and welfare center the Sensory Profile test and clinical observation were also used often. Regarding the level of knowledge of evaluation tools and the desire to participate further in education, 30 (44.8%) of the respondents had not completed their education, and 42 (62.7%) rated their knowledge level as generally low. When asked about the importance of using a manual to guide them in their use of evaluation tools, 66 (98.6%) answered positively, and 66 (98.6%) answered that they needed specialized training in the use of evaluation tools. Conclusion : This study makes it possible to understand the use and status of evaluation tools as used by different institutions in Korea in the field of child occupational therapy It is anticipated that it will provide the basis for introducing existing evaluation tools and preparing new evaluation tools to be used in this field in Korea.

Retrieval of Hourly Aerosol Optical Depth Using Top-of-Atmosphere Reflectance from GOCI-II and Machine Learning over South Korea (GOCI-II 대기상한 반사도와 기계학습을 이용한 남한 지역 시간별 에어로졸 광학 두께 산출)

  • Seyoung Yang;Hyunyoung Choi;Jungho Im
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.933-948
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    • 2023
  • Atmospheric aerosols not only have adverse effects on human health but also exert direct and indirect impacts on the climate system. Consequently, it is imperative to comprehend the characteristics and spatiotemporal distribution of aerosols. Numerous research endeavors have been undertaken to monitor aerosols, predominantly through the retrieval of aerosol optical depth (AOD) via satellite-based observations. Nonetheless, this approach primarily relies on a look-up table-based inversion algorithm, characterized by computationally intensive operations and associated uncertainties. In this study, a novel high-resolution AOD direct retrieval algorithm, leveraging machine learning, was developed using top-of-atmosphere reflectance data derived from the Geostationary Ocean Color Imager-II (GOCI-II), in conjunction with their differences from the past 30-day minimum reflectance, and meteorological variables from numerical models. The Light Gradient Boosting Machine (LGBM) technique was harnessed, and the resultant estimates underwent rigorous validation encompassing random, temporal, and spatial N-fold cross-validation (CV) using ground-based observation data from Aerosol Robotic Network (AERONET) AOD. The three CV results consistently demonstrated robust performance, yielding R2=0.70-0.80, RMSE=0.08-0.09, and within the expected error (EE) of 75.2-85.1%. The Shapley Additive exPlanations(SHAP) analysis confirmed the substantial influence of reflectance-related variables on AOD estimation. A comprehensive examination of the spatiotemporal distribution of AOD in Seoul and Ulsan revealed that the developed LGBM model yielded results that are in close concordance with AERONET AOD over time, thereby confirming its suitability for AOD retrieval at high spatiotemporal resolution (i.e., hourly, 250 m). Furthermore, upon comparing data coverage, it was ascertained that the LGBM model enhanced data retrieval frequency by approximately 8.8% in comparison to the GOCI-II L2 AOD products, ameliorating issues associated with excessive masking over very illuminated surfaces that are often encountered in physics-based AOD retrieval processes.

The causative organisms of pediatric empyema in Korea (소아 농흉 원인균에 대한 다기관 연구(1999. 9-2004. 8))

  • Yum, Hye-yung;Kim, Woo Kyung;Kim, Jin Tak;Kim, Hyun Hee;Rha, Yeong Ho;Park, Yong Min;Sohn, Myung Hyun;Ahn, Kang Mo;Lee, Soo Young;Hong, Su Jong;Lee, Hae Ran
    • Clinical and Experimental Pediatrics
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    • v.50 no.1
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    • pp.33-39
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    • 2007
  • Purpose : In spite of medical advances, empyema is a serious complication of pneumonia in children. Vaccination practices and antibiotic prescribing practices promote the change of clinical manifestations of empyema and causative organisms. So we made a nationwide clinical observation of 122 cases of empyema in children from 32 hospitals during the 5 year period from September 1999 to August 2004. Methods : Demographic data, and clinical information on the course and management of empyema patients were collected retrospectively from medical records in secondary and tertiary hospitals in Korea. Results : One hundred twenty two patients were enrolled from 35 hospitals. The most frequent age group was 1-3 years, accounting for 48 percent of all cases. The male to female sex ratio was 1.2:1. The main symptoms were cough, fever, respiratory difficulty, lethargy and chest pain in order of frequency. Hematologic findings on admission revealed decreased hemoglobin levels ($10.4{\pm}1.6g/dL$) and increased leukocyte counts ($16,234.3{\pm}10,601.8/{\mu}L$). Pleural fluid obtained from patients showed high leukocyte counts ($30,365.8{\pm}64,073.0/{\mu}L$), high protein levels ($522.3{\pm}1582.3g/dL$), and low glucose levels ($88.1{\pm}523.5mg/dL$). Findings from pleural fluid cultures were positive in 80 cases(65.6 percent). The most common causative agent was Streptococcus pneumoniae. The majority of patients were treated with antibiotics and closed drainage. Some patients needed open drainage (16.4 percent) or decortication (3.3 percent). The mean duration of hospitalization was $28.6{\pm}15.3days$. Conclusion : We analyzed childhood empyema patients during a period of 5 years in Korean children. The most frequent age group was 1-3 years and the most common causative agent was Streptococcus pneumoniaeiae. The majority of patients were treated with antibiotics and close drainage.

Studies on the Functional Interrelation between the Vestibular Canals and the Extraocular Muscles (미로반규관(迷路半規管)과 외안근(外眼筋)의 기능적(機能的) 관계(關係)에 관(關)한 연구(硏究))

  • Kim, Jeh-Hyub
    • The Korean Journal of Physiology
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    • v.8 no.2
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    • pp.1-17
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    • 1974
  • This experiment was designed to explore the specific functional interrelations between the vestibular semicircular canals and the extraocular muscles which may disclose the neural organization, connecting the vestibular canals and each ocular motor nuclei in the brain system, for vestibuloocular reflex mechanism. In urethane anesthetized rabbits, a fine wire insulated except the cut cross section of its tip was inserted into the canals closely to the ampullary receptor organs through the minute holes provided on the osseous canal wall for monopolar stimulation of each canal nerve. All extraocular muscles of both eyes were ligated and cut at their insertio, and the isometric tension and EMG responses of the extraocular muscles to the vestibular canal nerve stimulation were recorded by means of a physiographic recorder. Upon stimulation of the semicircular canal nerve, direction if the eye movement was also observed. The experimental results were as follows. 1) Single canal nerve stimulation with high frequency square waves (240 cps, 0. 1 msec) caused excitation of three extraocular muscles and inhibition of remaining three muscles in the bilateral eyes; stimulation of any canal nerve of a unilateral labyrinth caused excitation (contraction) of the superior rectus, superior oblique and medial rectus muscles and inhibition (relaxation) of the inferior rectus, inferior oblique and lateral rectos muscles in the ipsilateral eye, and it caused the opposite events in the contralateral eye. 2) By the overlapped stimulation of triple canal nerves of a unilateral labyrinth, unidirectional (excitatory or inhibitory) summation of the individual canal effects on a given extraocular muscles was demonstrated, and this indicates that three different canals of a unilateral vestibular system exert similar effect on a given extraocular muscles. 3) Based on the above experimental evidences, a simple rule by which one can define the vestibular excitatory and inhibitory input sources to all the extraocular muscles is proposed; the superior rectus, superior oblique and medial rectus muscles receive excitatory impulses from the ipsilateral vestibular canals, and the inferior rectus, inferior oblique and lateral rectus muscles from the contralateral canals; the opposite relationship applies for vestibular inhibitory impulses to the extraocular muscles. 4) According to the specific direction of the eye movements induced by the individual canal nerve stimulation, an extraocutar muscle exerting major role (a muscle of primary contraction) and two muscles of synergistic contraction could be differentiated in both eyes. 5) When these experimental results were compared to the well known observations of Cohen et al. (1964) made in the cats, extraocular muscles of primary contraction were the same but those of synergistic contraction were partially different. Moreover, the oblique muscle responses to each canal nerve excitation appeared to be all identical. However, the responnes of horizontal (medial and lateral) and vertical (superior and inferior) rectus muscles showed considerable differences. By critical analysis of these data, the author was able to locate theoretical contradictions in the observations of Cohen et al. but not in the author's results. 6) An attempt was also made to compare the functional observation of this experiment to the morphological findings of Carpenter and his associates obtained by degeneration experiments in the monkeys, and it was able to find some significant coincidence between there two works of different approach. In summary, the author has demonstrated that the well known observations of Cohen et al. on the vestibulo-ocular interrelation contain important experimental errors which can he proved by theoretical evaluation and substantiated by a series of experiments. Based on such experimental evidences, a new rule is proposed to define the interrelation between the vestibular canals and the extraocular muscles.

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Evaluation of Puretone Threshold Using Periodic Health Examination Data on Noise-exposed Workers in Korea (소음 특수건강진단 자료를 이용한 순음청력검사 평가)

  • Kim, Yang-Ho;Choi, Jung-Keun;Park, Jung-Sun;Moon, Young-Han;Kim, Kyoo-Sang
    • Journal of Preventive Medicine and Public Health
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    • v.32 no.1
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    • pp.30-39
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    • 1999
  • Objectives. This study was carried out to evaluate hearing impairment judgement and to investigate the differences in various diagnostic criteria for noise-induced hearing loss (NIHL) among workers who required for close observation (C). Methods. Out of 731,029 workers who had taken the specific periodic health examination in 1994, we used the audiometric data on 37,999 workers (C) eliminating the employees who had previous otologic problems. Many investigators have being using different criteria for the evaluation of hearing impairment. In this study, we used the criteria of early (1989-1994), current, compensation for NIHL in Korea, 2-, 3-, 4-divided classification and hearing loss at 4,000 Hz and compared the evaluation results. Results. The prevalences of C and workers who had occupational disease $(D_1)$ diagnosed for NIHL were 11.1 % and 0.44 %. There were significant difference in the prevalences of C and $D_1$, depending on different province of Korea. Pure tone averages (PTAs) were not appropriately applied in their evaluation 97% of workers whom we studied on were below the level of mild hearing loss judged by ISO standard. However, there were wide variations in the prevalence rate of mild hearing loss by diagnostic criteria. Thus, there were different judgements in determining the degree of NIHL depending on which diagnostic criteria were utilized. PTAs were found 20.54 (Rt) and 20.74 (Lt) when the method of 3-divided classification was applied for audiometric data. The degree of hearing impairment of the left ear was more severe than that of right ear. The prevalence of normal hearing threshold below 20 dB was 75.4% and the range of difference in both ear was below 10 dB. Right sided hearing threshold levels were 21.08 dB (500 Hz), 18.44 dB (1,000 Hz), 22.09 (2,000 Hz) and 52.36 dB (4,000 Hz). There was typical high frequency loss (C5-dip at 4,000 Hz) above 30 - 40 dB in normal hearing level. The increasing trend in hearing threshold level was gradually decreased by the increase of PTAs. The difference between PTAs and threshold at 4,000 Hz was about 10 dB. Conclusions. We could found that PTAs in the previous examination were not appropriately evaluated. This study revealed that they did not use unique criteria for managing the workers of NIHL. For the prevention of NIHL, it was found that the quality control on diagnosis and comprehensive management program were required, especially for those of hearing loss (C).

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