• Title/Summary/Keyword: historical frequency analysis

Search Result 128, Processing Time 0.027 seconds

The Process and Method to Set a Mountainous Scenic Site's Designated Area

  • Han, Gab Soo;Kim, Soonki;Ham, Kwang Min
    • Journal of Forest and Environmental Science
    • /
    • v.36 no.1
    • /
    • pp.47-54
    • /
    • 2020
  • A "Scenic Site" is an official heritage category legally defined as a "scenic site of outstanding artistic value with excellent scenic views." However, the subjective interpretation of the term causes several problems. This study suggested a systematic, organized process of designating a listed area as a scenic site after careful and detailed quantitative and qualitative analysis. Indicators were identified for each of the two analyses, and then scored and weighted. Quantitative indicators were distributed within 5 points for each indicator. Water, which is a natural indicator, based on distance from river boundaries. Forest landscapes were assigned in consideration of forest physiognomy and age class. Land use was allocated in consideration of land cover type and, in case of development site, '-' score was assigned. Cultural heritage conservation area, which is historical and cultural indicator, was distributed by distance within a maximum of 500 meters. Visibility, an indicator of landscape value, was assigned according to the frequency of visibility. The weight of each indicator was calculated by considering the value of each item. The weight of distribution of cultural resources is relatively high, while other items were set the same. In case of land use, however, '-' score was given according to the grade. Qualitative indicators, on the other hand, were considered terrain, landscape zone, ownership, intellectual boundary, and land category. The applicability of the proposed process and method was examined by applying the existing methods and criteria used for designating scenic spots. Opinions of subject-matter experts were incorporated in the identification of the indicators and in the result review stage. In the future, it is necessary to apply this method while designating scenic sites so as to establish an objective, scientific designation process.

Drought over Seoul and Its Association with Solar Cycles

  • Park, Jong-Hyeok;Chang, Heon-Young
    • Journal of Astronomy and Space Sciences
    • /
    • v.30 no.4
    • /
    • pp.241-246
    • /
    • 2013
  • We have investigated drought periodicities occurred in Seoul to find out any indication of relationship between drought in Korea and solar activities. It is motivated, in view of solar-terrestrial connection, to search for an example of extreme weather condition controlled by solar activity. The periodicity of drought in Seoul has been re-examined using the wavelet transform technique as the consensus is not achieved yet. The reason we have chosen Seoul is because daily precipitation was recorded for longer than 200 years, which meets our requirement that analyses of drought frequency demand long-term historical data to ensure reliable estimates. We have examined three types of time series of the Effective Drought Index (EDI). We have directly analyzed EDI time series in the first place. And we have constructed and analyzed time series of histogram in which the number of days whose EDI is less than -1.5 for a given month of the year is given as a function of time, and one in which the number of occasions where EDI values of three consecutive days are all less than -1.5 is given as a function of time. All the time series data sets we analyzed are periodic. Apart from the annual cycle due to seasonal variations, periodicities shorter than the 11 year sunspot cycle, ~ 3, ~ 4, ~ 6 years, have been confirmed. Periodicities to which theses short periodicities (shorter than Hale period) may be corresponding are not yet known. Longer periodicities possibly related to Gleissberg cycles, ~ 55, ~ 120 years, can be also seen. However, periodicity comparable to the 11 year solar cycle seems absent in both EDI and the constructed data sets.

Climate-instigated disparities in supply and demand constituents of agricultural reservoirs for paddy-growing regions

  • Ahmad, Mirza Junaid;Cho, Gun-ho;Choi, Kyung-sook
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2022.05a
    • /
    • pp.516-516
    • /
    • 2022
  • Agricultural reservoirs are critical water resources structures to ensure continuous water supplies for rice cultivation in Korea. Climate change has increased the risk of reservoir failure by exacerbating discrepancies in upstream runoff generation, downstream irrigation water demands, and evaporation losses. In this study, the variations in water balance components of 400 major reservoirs during 1973-2017 were examined to identify the reservoirs with reliable storage capacities and resilience. A conceptual lumped hydrological model was used to transform the incident rainfall into the inflows entering the reservoirs and the paddy water balance model was used to estimate the irrigation water demand. Historical climate data analysis showed a sharp warming gradient during the last 45 years that was particularly evident in the central and southern regions of the country, which were also the main agricultural areas with high reservoir density. We noted a country-wide progressive increase in average annual cumulative rainfall, but the forcing mechanism of the rainfall increment and its spatial-temporal trends were not fully understood. Climate warming resulted in a significant increase in irrigation water demand, while heavy rains increased runoff generation in the reservoir watersheds. Most reservoirs had reliable storage capacities to meet the demands of a 10-year return frequency drought but the resilience of reservoirs gradually declined over time. This suggests that the recovery time of reservoirs from the failure state had increased which also signifies that the duration of the dry season has been prolonged while the wet season has become shorter and/or more intense. The watershed-irrigated area ratio (W-Iratio) was critical and the results showed that a slight disruption in reservoir water balance under the influence of future climate change would seriously compromise the performance of reservoirs with W-Iratio< 5.

  • PDF

Development of Design Blast Load Model according to Probabilistic Explosion Risk in Industrial Facilities (플랜트 시설물의 확률론적 폭발 위험도에 따른 설계폭발하중 모델 개발)

  • Seung-Hoon Lee;Bo-Young Choi;Han-Soo Kim
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.37 no.1
    • /
    • pp.1-8
    • /
    • 2024
  • This paper employs stochastic processing techniques to analyze explosion risks in plant facilities based on explosion return periods. Release probability is calculated using data from the Health and Safety Executive (HSE), along with annual leakage frequency per plant provided by DNV. Ignition probability, derived from various researchers' findings, is then considered to calculate the explosion return period based on the release quantity. The explosion risk is assessed by examining the volume, radius, and blast load of the vapor cloud, taking into account the calculated explosion return period. The reference distance for the design blast load model is determined by comparing and analyzing the vapor cloud radius according to the return period, historical vapor cloud explosion cases, and blast-resistant design guidelines. Utilizing the multi-energy method, the blast load range corresponding to the explosion return period is presented. The proposed return period serves as a standard for the design blast load model, established through a comparative analysis of vapor cloud explosion cases and blast-resistant design guidelines. The outcomes of this study contribute to the development of a performance-based blast-resistant design framework for plant facilities.

Drought Analysis and Assessment by Using Land Surface Model on South Korea (지표수문해석모형을 활용한 국내 가뭄해석 적용성 평가)

  • Son, Kyung-Hwan;Bae, Deg-Hyo;Chung, Jun-Seok
    • Journal of Korea Water Resources Association
    • /
    • v.44 no.8
    • /
    • pp.667-681
    • /
    • 2011
  • The objective of this study is to evaluate the applicability of a Land Surface Model (LSM) for drought analysis in Korea. For evaluating the applicability of the model, the model was calibrated on several upper dam site watersheds and the hydrological components (runoff and soil moisture) were simulated over the whole South Korea at grid basis. After converting daily series of runoff and soil moisture data to accumulated time series (3, 6, 12 months), drought indices such as SRI and SSI are calculated through frequency analysis and standardization of accumulated probability. For evaluating the drought indices, past drought events are investigated and drought indices including SPI and PDSI are used for comparative analysis. Temporal and spatial analysis of the drought indices in addition to hydrologic component analysis are performed to evaluate the reproducibility of drought severity as well as relieving of drought. It can be concluded that the proposed indices obtained from the LSM model show good performance to reflect the historical drought events for both spatially and temporally. From this point of view, the LSM can be useful for drought management. It leads to the conclusion that these indices are applicable to domestic drought and water management.

Analysis of the Research Trends on Business Archives: Focusing on the Topic Modeling Analysis (기업 아카이브에 관한 연구 동향 분석: 토픽모델링 분석을 중심으로)

  • Kim, Hyosun
    • Journal of Korean Society of Archives and Records Management
    • /
    • v.21 no.3
    • /
    • pp.163-186
    • /
    • 2021
  • The purpose of this study is to analyze research trends on overseas business archives, compare them with domestic and related prior studies, and present the direction of the development of domestic business archives research. For the research analysis, bibliography from 493 papers was collected using four academic databases: Web of Science, Scopus, LISA (ProQuest), LISS (EBSCOhost). Following data collection, data analysis was conducted and focused on the publication status of related papers, major journals, research forms, and researcher information. In addition, unique words were extracted through the data processing of English abstracts, and the frequency of the key words was identified. Through topic modeling, this study extracted seven topics from the entire literature group, analyzed the publication trends of the papers corresponding to each topic, and examined the topics and representative papers of that topic. The names for these topics were assigned as "access and usability of business records'," "information/evidence value of business records," "importance and operational strategy of business archives," "record management as a business heritage," "management of business records in digital environments," "preservation and disposal of business records," and "historical value of business records." Based on the prior research and analysis results, this study proposed implications for the development and expansion of future research on the domestic business archives.

Predictive analysis of minimum inflow using synthetic inflow in reservoir management: a case study of Seomjingang Dam (자료 발생 기법을 활용한 저수지 최소유입량 예측 기법 개발 : 섬진강댐을 대상으로)

  • Lee, Chulhee;Lee, Seonmi;Lee, Eunkyung;Ji, Jungwon;Yoon, Jeongin;Yi, Jaeeung
    • Journal of Korea Water Resources Association
    • /
    • v.57 no.5
    • /
    • pp.311-320
    • /
    • 2024
  • Climate change has been intensifying drought frequency and severity. Such prolonged droughts reduce reservoir levels, thereby exacerbating drought impacts. While previous studies have focused on optimizing reservoir operations using historical data to mitigate these impacts, their scope is limited to analyzing past events, highlighting the need for predictive methods for future droughts. This research introduces a novel approach for predicting minimum inflow at the Seomjingang dam which has experienced significant droughts. This study utilized the Stochastic Analysis Modeling and Simulation (SAMS) 2007 to generate inflow sequences for the same period of observed inflow. Then we simulate reservoir operations to assess firm yield and predict minimum inflow through synthetic inflow analysis. Minimum inflow is defined as the inflow where firm yield is less than 95% of the synthetic inflow in many sequences during periods matching observed inflow. The results for each case indicated the firm yield for the minimum inflow is on average 9.44 m3/s, approximately 1.07 m3/s lower than the observed inflow's firm yield of 10.51 m3/s. The minimum inflow estimation can inform reservoir operation standards, facilitate multi-reservoir system reviews, and assess supplementary capabilities. Estimating minimum inflow emerges as an effective strategy for enhancing water supply reliability and mitigating shortages.

Analysis of Music Therapy Research in Professional Journals in Korea (국내 음악치료 전문 학술지 연구 현황 분석)

  • Cho, Hyun Ah
    • Journal of Music and Human Behavior
    • /
    • v.10 no.2
    • /
    • pp.55-77
    • /
    • 2013
  • The purpose of this study was to identify current trends in music therapy literature in Korea in order to provide the groundwork for future research. Therefore, 122 articles from the Korean Journal of Music Therapy (KJMT) from 1999 to 2012 and 76 articles from the Journal of Music and Human Behavior (JMHB, formerly known as Korean Journal of Music Therapy Education) from 2004 to 2012 were analyzed. Analysis was performed by identifying the frequency and percentage of the following items: type, population, topic, and methodology of published articles. In addition, the results obtained were compared and contrasted between these two publications. Overall, it was found that there was a high prevalence of descriptive studies (KJMT, 46%,; JMHB, 45%), applied research (KJMT, 51%; JMHB 66%), and quantitative studies (KJMT, 82%; JMHB 37%). In addition, ordinary people with no particular diagnosis were the most often studied population (34%). Differences were found in that a historical study was only found in KJMT whereas a philosophical study was published only in JMHB. Further analysis revealed that JMHB included a higher proportion of applied research than KJMT. In KJMT, quantitative research was appeared twice as often as qualitative and mixed-method research combined. On the other hand, a similar number of each of the three methodological types of studies appeared in JMHB. In conclusion, this study indicates that more effort should be made to increase the quantity and improve the quality of professional publications in the field of music therapy in Korea.

A Study on Self-image and Clothing-Purchasing-Behavior of Adolescence (여고생의 자아 이미지와 의복구매 행동에 관한 연구)

  • 김영신;한명숙
    • The Research Journal of the Costume Culture
    • /
    • v.6 no.1
    • /
    • pp.94-109
    • /
    • 1998
  • The objective of this study is to measure self-image of adolescence, analyze empirically clothing-purchasing-behavior of adolescence and clarify correlation of two variables, self-image and clothing-purchasing-behavior. For this purpose, the techniques involve theoretical studies and researches based on historical obtained from previous related studies and surveys, 431 high school female students who reside in Seoul are asked to answer selected survey questions to examine three aspects, clothing-purchasing-behavior, self-image and demographics. The evaluation of surveyed information is analyzed by statistical techniques to improve the accuracy of data. Statistical methods used are as follows; Descriptive(frequency, mean, percentage), Factor Analysis(varimax rotation), Crosstabs(Chi-square), T-test, One-Way ANOVA< Correlation Analysis, Reliability Analysis and Duncan's Multiple Range Test. The mjor results of this study were as follows: Firstly, there is a discrepancy between real self-image and ideal self-image. Furthermore more significant differences is seen from physical aspects than psychological aspects. Consequently, research proves that the difference derived from their ideal situation and real situation leads to psychological unstableness. In addition, making their real self-image is dependent upon several elements such things as family economic level, pocket money, expenditure on clothing. Therefore, it is critical to combine all factors in order to decide how much to spend for children's clothing and pocket money in parents point of view. Secondly, research shows that shows hat there is correlated relationship between average expenditure on clothing and presence of mother's job. Average expenditure on clothing is, generally, influenced by vogue which is tend to be changed seasonally. It, also, shows that there is positive linear regression between expenditure on clothe and sensitivity for vogue. That is to say, dependent variable, expenditure on clothing, is varied as independent variable, sensitivity for vogue, changes. Female high school students are likely to give much value on brand. Moreover people who are spending more money on clothes have higher tendencies in prompt purchases than who are not. Thirdly, the analysis of clothing-purchasing-behavior and self-image shows that the difference between real self-image and ideal self-image draws the main reason of dissatisfaction after purchase of clothes. As a consequence, their unfilled needs lead them to keep making another purchase to satisfy themselves. Therefore, it is strongly recommended that parents' advices and directions on their children's money spending on clothes are imperative to establish well-behaved purchasing patterns.

  • PDF

Analysis of the Study Trend of Glass Ceiling by Period Using Text Mining (텍스트 마이닝을 이용한 시대별 유리천장 연구동향 분석)

  • Kim, Young-Man;Lee, Jin Gu
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.8
    • /
    • pp.376-387
    • /
    • 2021
  • This study is to analyze the research trends related to the 'glass ceiling' phenomenon using big data analysis methods and to suggest social implications. To analyze the research trends of 'glass ceiling', the historical event that broke the 'glass ceiling' was set as an important issue, and keywords were collected by dividing park's term into three. Before, throughout and after, her term. As a result of frequency analysis, research was conducted based on 'public servants' which was selected as the main keyword in the first period, while 'women's work family compatibility' was chosen as the main keyword group in the second period. In the third period, keywords for women's occupational groups were being diversified. As a result of applying CONCOR techniques to make the studied main topics grouped, we were able to confirm that the main issues were the differentiating factors, the customary gender discrimination culture, the jobs aimed for studying, the work-family balance, the glass ceiling and the organizational performance adjustment factors, the public sector, organizational performance, and the private sector. Besides work-family compatibility support system, it was suggested as a social implication that research on improving the system to resolve the glass ceiling factor and to expand the target jobs to give solutions to real-life issues were needed, and also suggested that research on the 'glass ceiling' which the general public perceives through social medias or articles in the news, was needed in the future.