• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.1
• /
• pp.65-72
• /
• 2010

In this study, the performances of a medium grade IMU which is aimed for Mobile Mapping System and a low grade IMU for pedestrian navigation are analyzed through simulations under GPS signal blockage. In addition, an analysis on the accuracy improvement of barometer, electronic compass, or multi-sensor(combination of barometer and electronic compass) to correct medium grade or low grade IMU errors in the situation of GPS signal blockage is performed. With the medium grade IMU, the three dimensional positioning error from INS exceeds the demanded accuracy of 5m when the block time is over 30 seconds. When we correct IMU with barometer, compass, or multi-sensor, however, the demanded accuracy is maintained up to 60 seconds. In addition, barometer is more effective than the electronic compass when they are combined. In case of low grade IMU like MEMS IMU, the three dimensional positioning error from INS exceeds the demanded accuracy of 20m when the block time is over 15 seconds. When we correct INS with barometer, compass, or multi-sensor, however, the demanded accuracy is maintained up to 15 seconds in simulation results. On the contrary to medium grade IMU, electronic compass is more effective than the barometer in case of low velocity such as pedestrian navigation. It is expected that the analysis suggested a method to decrease position or attitude error using aided sensor integration when MMS or pedestrian navigation is operated under 1he environment of GPS signal blockage.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.12
• /
• pp.4812-4818
• /
• 2010

Neck pain was commonly experienced by both adolescents and adults. The neck disability index(NDI) was the most commonly used self-report measure for evaluating status in neck pain. The objective of this study is to research the prevalence of the NDI in their 20's of college students in department of physical therapy. The data were collected from the NDI questionnaire of college students(males: 229, females: 405) for functional disability measures. Statistical analysis was carried out with SPSS 12.0 program, which was used for descriptive statistics, independent samples test and Pearson correlation analysis. The results were : First, 'headache' item was showed 'the highest prevalence' in second choice demonstrating the neck disability and 'pain intensity' in third choice. Second, female(46.4%) was higher distribution than male(36.3%) on score, percentage and grade of NDI(p<0.05). Third, the NDI grade was investigated that it is composed of 'no disability(63.8%)', 'mild disability(35.4%)', and 'moderate disability(0.9%)' in male and 'no disability(53.6%)', 'mild disability(44.7%)', 'moderate disability(1.5%)' and 'severe disability(0.2%)' in female. Fourth, there was a statically significant relationship between NDI grade and NDI items(p<0.05). These results have specific meaning as future clinical and epidemiological studies. Also, it is needed to education and preparation on prevention and management of neck disability among college students.

• Journal of Korea Water Resources Association
• /
• v.46 no.2
• /
• pp.195-204
• /
• 2013

As drought is phenomenon of nature with unavoidability and repeated characteristic, it is necessary to plan to respond to it in advance and construct drought management system to minimize its damage. This study suggested standard for classification of drought, which is appropriate for our nation to respond to drought by assessing drought severity in the regions for this study. For data collection, 61 locations were selected - the locations keep precipitation data over 30 years of observation. And data for monthly precipitation for 37 years from 1973 were used. Based on this, this study classified unified drought interval into four levels using drought situation phases which are used in government. For standard for classification of drought severity fit to our nation, status of main drought was referred and these are classified based on accumulated probability of drought - 98~100% Exceptional Drought, 94~98% Extreme Drought, 90~94% Severe Drought, 86~90% Moderate Drought. Drought index (SPI, PDSI) was made in descending order and quantitative value of drought index fit to standard of classification for drought severity was calculated. To compare classification results of drought severity of SPI and PDSI with actual drought, comparison by year and month unit were analyzed. As a result, in comparison by year and comparison by month unit of SPI, drought index of each location was mostly identical each other between actual records and analyzed value. But in comparison by month unit of PDSI for same period, actual records did not correspond to analyzed values. This means that further study about mutual supplement for these indexes is necessary.

• 한국지구과학회:학술대회논문집
• /
• 2010.04a
• /
• pp.70-70
• /
• 2010

이 연구의 목적은 귀추적 탐구 방법과 관련된 전략들을 적용하여 지구온난화에 관련되어 측정된 다양한 유형의 데이터를 관련된 사실, 원리, 법칙, 선행 연구 결과 등을 토대로 지구통합적인 관점과 지구계를 구성하는 요소들 간의 상호작용과 영향을 중심으로 재해석하고 이해하는 것이다. 지구과학(지구시스템과학)의 학문 성격, 최근 동향, 본성 및 탐구 대상의 특성에 대한 내용과 지구과학의 본질적 속성에 잘 부합하는 귀추적 탐구 방법에 대해 학습한 후, 학생들은 인천 및 다양한 지역의 기상과 해양 자료 분석을 통하여 관찰되는 현상(결과)의 원인과 영향을 파악하는 연구 활동을 하였다. 이 과정에서 귀추적 탐구를 충분히 이해할 수 있도록, 과학 탐구에서 귀추적 탐구 방법을 사용하는 과학자들의 예시와 모의 활동을 통하여, 귀추적 탐구 방법에 사용되는 다양한 사고 전략(예, 데이터의 재구성 전략, 유추 전략, 개념적 결합 전략 등)에 대한 예시를 경험하였다. 학생들은 지구온난화에 관련되어 나타나는 현상(조사된 사항 포함)과 영향에 대해 지구시스템적으로 이해하고 재해석하기 위해 지구시스템을 구성하는 요소(예, 수권, 대기권)와 관련된 데이터 정보를 검색하고 수집하였다. 1) 지구시스템과 지구온난화에 대한 조사하고, 2) 지구온난화 및 기후변화의 변동성 확인한 후, 3) 지구온난화와 관련된 선행 연구 결과 분석하였다. 또한, 지구과학의 본질적 속성에 잘 부합하는 귀추적 탐구 방법의 이해와 적용하는 과정에서 1) 지구 온난화 및 기후 변화의 실태 파악하고, 2) 인천 지역의 월별, 계절별 기온 변화 분석 및 경향 조사(탐색: 연구문제 규명)한 후, 3) 인천과 속초 지역의 기온, 수온의 변화 추이 및 분석 (조사: 원인 조사 과정)하였다. 4) 속초 지역의 평균해면기압변화 추이 및 분석한 후, 그 결과를 토대로 5) 문헌조사 및 선행연구 결과 분석을 통한 지구 온난화의 영향을 미치는 요인 재검토 및 확인(선택 및 설명)하여, 6) 인천지역과 속초지역의 지구온난화 원인 분석 및 문제점 보완(설명)하기 위해 7) 겨울철 지구온난화가 더 심각한지 부산지역과 포항지역의 자료 분석을 통하여 연구 결과 내용의 보완 (추가 조사 및 설명)한 후, 8) 분석 결과 및 해석 내용을 전문가와 상담 실시하였다. 이 연구는 연구를 진행하면서 얻은 결과를 교육적 측면에서 다시 정리해 보면 다음과 같다. 우선, 학생들의 지구환경적 문제 해결 과정에서 귀추적 탐구 방법을 활용한 문제 해결 능력을 향상시켰다. 아울러, 지구과학의 탐구 본성, 최근 동향, 탐구대상의 특성 등의 학습을 통해 지구과학도로서의 기본적인 소양과 자질 향상에 기여하였으며, 사회과학의 연구방법을 순수과학연구에 접목하여 과학자로서의 문제해결 능력과 시스템 사고력을 향상시켰다.

• Review of Culture and Economy
• /
• v.20 no.1
• /
• pp.105-128
• /
• 2017

The purpose of this paper is to analyze the impact of distributors on the movie exhibition by distributor types. For the analysis, the concept 'screen elasticity of box office' is adopted. Using the weekly screening data of 94 hit movies released in Korea in 2014 and 2015, the panel analysis estimates the 'screen elasticity of box office' with the Hausman-Taylor estimator. The results show that the screen elasticity of box office is smaller for vertically integrated distributors(CJ E&M and Lotte Entertainment) and Hollywood distributors than the local distributors(Showbox and NEW) that do not own integrated cinemas. This means that exhibitors allocate a larger number of screens to vertically integrated distributors and Hollywood distributors. As the two distributor groups had higher market share during the period, the results imply that the screen elasticity is related to the market performance of distributors. Smaller screen elasticity of the vertically integrated distributors might be related not to the ownership to theaters but to higher market share of the distributors.

• The Journal of the Korea Contents Association
• /
• v.22 no.4
• /
• pp.754-764
• /
• 2022

This study began with a reflection and review of looking back on the anti-Japanese movement of Jeju Haenyeo. The Jeju Haenyeo Anti-Japanese Movement is the largest women's solidarity movement in Korea, with the struggle for the right to survive expanding to the anti-Japanese movement. Kang Kwan-Soon of young intellectuals in Jeju carried out an enlightenment campaign and made the unfair lives of Haenyeo into song lyrics to promote the anti-Japanese consciousness. 'Song of Haenyeo' has been excluded from the record for reasons of using Japanese melodies of 'Tokyo March', not traditional folk songs, and the socialist forces behind it. The study of Jeju Haenyeo is an important basic reference for the study of the anti-Japanese movement that successfully led the Jeju Haenyeo's human rights struggle. Oral tradition songs are the most fundamental art form. Through this research to revive the spirit of the anti-Japanese movement and remember the value of their sacrifices and contributions through comparative of the two songs.

• The Korean Journal of Applied Statistics
• /
• v.35 no.4
• /
• pp.553-568
• /
• 2022

The Household Income and Expenditure Survey is a representative survey of Statistics Korea, which aims to measure and analyze national income and consumption levels and their changes by understanding the current state of household balances. Recently, the disconnection problem in these time series caused by the large-scale reorganization of the survey methods in 2017 and 2019 has become an issue. In this study, we model the characteristics of the time series in the Household Income and Expenditure Survey up to 2016, and use the modeling to compute forecasts for linking the expenditures in 2017 and 2018. In order to evenly reflect the characteristics across all expenditure item series and to reduce the impact of a specific forecast model, we synthesize a total of 8 models such as regression models, time series models, and machine learning techniques. In particular, the noteworthy aspect of this study is that it improves the forecast by using the optimal combination technique that can exactly reflect the hierarchical structure of the Household Income and Expenditure Survey without loss of information as in the top-down or bottom-up methods. As a result of applying the proposed method to forecast expenditure series from 2017 to 2019, it contributed to the recovery of time series linkage and improved the forecast. In addition, it was confirmed that the hierarchical time series forecasts by the optimal combination method make linkage results closer to the actual survey series.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.2
• /
• pp.193-198
• /
• 1997

The purpose of this study was to find out a suitable resin to remove $NO_3-N$ from groundwater. Four different commercial resins differentiated by type, porosity and nitrate selectivity were used to compare the performance of nitrate removal. Gel type, Type 2 anion exchange resin was preferable when anion concentration of raw water was low. But efficiency of this resin decreased as flow rate increased. However, macroporous type resins were not affected by increasing flow rate. Macroporous resins were preferable when anion concentrations in raw water were high and high flow rate was proposed. And the general type resin showed better efficiency when sulfate concentrations were low. However the nitrate selective resin had better efficiency in treating raw water of high sulfate concentration. From the results, it may be drawn that nitrate selective resins are preferable to general type when a sulfate concentration in groundwater is over 50mg/l.

• Weed & Turfgrass Science
• /
• v.1 no.4
• /
• pp.6-12
• /
• 2012

A fact-finding survey was conducted to obtain the basic information on nation-wide weed distribution and farmer's opinions to weed control strategy in paddy field. Most respondents considered Echinochloa spp., Monochloa vaginalis, Sagittaria trifolia, and Scirpus juncoides etc. as dominate weeds in paddy fields. And herbicide resistant weed species were M. vaginalis, S. juncoides, E. oryzicola and S. pygmaea etc. Purchase guidances for herbicide selection, experience of farmers was 34.0% and dealers recommendation was 33.9% at farmer's level. And paddy field herbicides application frequence were one time 15.6% but twice 75.6%. Preferred herbicides were ranked in the following order: oxadizone 12% EC, butachlor 5% GR, butachlor 33% CS, mefenacet pyrazodulfuron-ethyl 21.42% SC, and oxadiargyl 1.7% EC etc. in paddy fields. And in most preferred foliar herbicide were bentazone MCPA 38.6% SL and bentazone cyhalop-butyl 18.5% ME, 48.5% and 22.3%, respectively.

• Korean journal of applied entomology
• /
• v.62 no.2
• /
• pp.69-78
• /
• 2023

The currently implemented Positive List System, sales manager training, and pesticide sales record systems focus on the safety of determined pesticide use, but the proposed agrochemical pharmacist (AP) system aims accurate diagnosis and reasonable prescription. In this study, 81% of famers claimed expert assistance for purchasing and applying pesticides, and 42~86% of sales managers insisted on the strengthening expertise in diagnosis and prescription. In the institutionalization of AP, a special implementation guideline is essential to embrace the present sales managers with long experience. Sales managers of commercial and agricultural cooperatives recognize the qualifications of agrochemical pharmacists as a strategy to differentiate themselves from competitors, and increase sales through market positioning of "pesticides prescribed by trustworthy agrochemical pharmacists", not sales managers anymore.