• Title/Summary/Keyword: research period

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The conditional risk probability-based seawall height design method

  • Yang, Xing;Hu, Xiaodong;Li, Zhiqing
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.6
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    • pp.1007-1019
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    • 2015
  • The determination of the required seawall height is usually based on the combination of wind speed (or wave height) and still water level according to a specified return period, e.g., 50-year return period wind speed and 50-year return period still water level. In reality, the two variables are be partially correlated. This may be lead to over-design (costs) of seawall structures. The above-mentioned return period for the design of a seawall depends on economy, society and natural environment in the region. This means a specified risk level of overtopping or damage of a seawall structure is usually allowed. The aim of this paper is to present a conditional risk probability-based seawall height design method which incorporates the correlation of the two variables. For purposes of demonstration, the wind speeds and water levels collected from Jiangsu of China are analyzed. The results show this method can improve seawall height design accuracy.

Effect of Thermal Stratification and Mixing on Phytoplankton Community Structure in the Western Channel of the Korea Strait

  • Shon, Dong-Hyun;Shin, Kyoung-Soon;Jang, Pung-Guk;Kim, Young-Ok;Chang, Man;Kim, Woong-Seo
    • Ocean and Polar Research
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    • v.30 no.3
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    • pp.261-275
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    • 2008
  • The profile of a fixed site at station M ($34.77^{\circ}N,\;129.13^{\circ}E$) in the Korea Strait was studied from March 2006 to February 2007. The aim was to understand the relationship between the annual thermal stratification pattern and seasonal variation in phytoplankton community structure. Physicochemical factors including temperature, salinity and nutrient concentrations, which strongly influence the proliferation and diversity of phytoplankton, were measured. The study period was divided into three due to the characteristic of thermohaline structures; mixed I (March-May 2006), stratified (June-November 2006) and mixed II(December 2006-Feburuary 2007). Diatoms dominated during the mixed I (89%) and II (48%) periods, while nanoplankton group occupied over 83% of total population during the stratified period. The dominant species during the mixed I and II was Chaetoceros socialis (47% and 29%, respectively), while during the stratified period Gyrodinium sp.(4%) was the most dominant. Averaged total chl a concentrations during the mixed I and II periods were 0.61 mg $m^{-3}$ and 0.72 mg $m^{-3}$, respectively, which were at least two-fold higher than that during the stratified period (0.30 mg $m^{-3}$). The vertical mixing and convection process of the water column induced nutrient supply from the bottom layer to the euphotic zone. It also led to the dominance of diatoms during the mixed periods, whereas small phytoplankton prevailed over large phytoplankton as stratification blocked the upward movement of nutrients to subsurface during the stratified period. During the mixed I and II periods, microplanktonic chl a dominated concentrations (50% and 48%, respectively), while picoplanktonic chl a occupied over 37% of total chl a during the stratified period.

Influence of Cooking, Storage Period, and Re-heating on Production of Cholesterol Oxides in Chicken Meat

  • Choe, Juhui;Min, Joong-Seok;Lee, Sang-Ok;Khan, Muhammad Issa;Yim, Dong Gyun;Lee, Mooha;Jo, Cheorun
    • Food Science of Animal Resources
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    • v.38 no.3
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    • pp.433-441
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    • 2018
  • The objective of present study was to investigate the effect of cooking and their combinations with re-heating methods on the formation of cholesterol oxidation products (COPs) in stored chicken thigh meat. Pan roasting, steaming, oven grilling, charcoal grilling, and microwaving were used for cooking. Re-heating of samples was done using the same cooking methods or microwaving after 3 and 6 d of refrigerated storage. Cooking and re-heating resulted in reduction of crude fat and cholesterol contents of chicken thigh meat depending on storage period before re-heating. Cooking and storage period had no influence on the total amount of COPs. The highest total amount of COPs was observed in meat samples cooked by steaming and reheated by microwaving after 6 d of storage, which showed similar value to raw chicken meat stored for 6 days. However, different re-heating methods formed different types of COPs depending on storage period before re-heating. The high amount (p<0.05) of 25-hydroxycholesterol or ${\alpha}-epoxide$ was detected in meat samples reheated by steaming or microwaving at 3 or 6 d of storage after steamed cooking, respectively. As a result, the combination of steaming and re-heating with microwaving could increase the total amount of COPs in chicken thigh meat and different cooking/re-heating methods could form different types of COPs, even though no significant difference in the total amount of COPs depending on storage period.

Rural residential environment: Identifying trends through text network analysis (텍스트 네트워크 분석을 활용한 농촌 주거환경 연구 동향)

  • Lee, Cha Hee
    • Journal of Korean Society of Rural Planning
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    • v.26 no.1
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    • pp.39-49
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    • 2020
  • The study analyzed the frequency of simultaneous occurrence of keywords presented in a total of 805 papers published in domestic journals from 1995 to 2019 by social network analysis(SNS) method, and examined core keywords of each period(5 years), in order to understand the research trends of the rural residential environment. The main results are as follows. First, as a result of the analysis of centrality, 'Community', 'Tourism' and 'Comprehensive Rural Village Development Project' were the top 3 keywords. Second, examined by each period, the top keywords are 'Eco Friendly' in 2000~2004, 'Tourism' in 2005~2009 and 2010~2014, 'Community' in 2015~2019. Third, comparing the structural characteristics of core keywords 2nd, 3rd, and 4th period, a network centering on 'Tourism' was clearly formed in the 2nd period. 'Tourism' was divided into 'Community' and a movement to form a separate group appeared in the 3rd period. In the 4th period, 'Community' was found to form a network without direct connection with 'Tourism'. The results of this study suggest the trend change of viewpoint for the rural area in the domestic research on rural residential environment. It has been confirmed that while the research had been carried out with the viewpoint of rural area as a 'tourist attraction' or 'sightseeing spot' for the urban citizens until the mid-2010s, in the research of late 2010s the viewpoint has settled down as a 'residential space' or 'space for new economic activities' of a variety of rural residents.

Comparative Analysis of Significant Wave Height and Wave Period Observed from Ocean Data and Drifting Buoys (해양기상부이와 표류부이에서 관측된 유의파고 및 파주기 비교 분석)

  • Hyeong-Jun Jo;Baek-Jo Kim;Reno Kyu-Young Choi;Min Roh;KiRyong Kang;Chul-Kyu Lee
    • Journal of Environmental Science International
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    • v.32 no.11
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    • pp.841-852
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    • 2023
  • In this study, the significant wave height and wave period of a specially designed observation system that connected two drifting buoys to an ocean data buoy was observed for 23 days from February 7 to 29, 2020, and the results were compared and analyzed. The results indicated that, in comparison to the ocean data buoy, the drifting buoy exhibited greater variability in significant wave height over shorter time intervals. The wave period of the ocean data buoy also appeared longer than that of the drifting buoy. The greater the observed significant wave height and wave period from both the ocean data and drifting buoys, the more pronounced the differences between the two observation instruments become. Moreover, the study revealed that the disparity in observation methods between the ocean data and drifting buoys did not significantly affect the significant wave height characteristics, as long as the period remained unchanged for up to half of the observation time.

Effect of Parity and Season of Calving on Service Period in Nili Ravi Buffalo in Pakistan

  • Naqvi, A.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.3
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    • pp.287-291
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    • 2000
  • The study was based on 1921 service period records of Nili Ravi buffaloes maintained at six dairy farms in Pakistan during the period 1978 to 1994. The mean service period was $237.57{\pm}4.5$ days in the over all data. The highest mean service period ($393.59{\pm}16.18$ days) was at MDF Rawalpindi and the lowest ($199.15{\pm}14.35$ days) was at MDF Peshawar. The difference was significant p<0.001. Late maturing buffaloes showed significantly longer service period as compared to early maturing buffaloes. Parity and seasonal effects on Service Period were studied. There was an overall trend of reduction in the length of service period with the increase in parity. The mean ($287.54{\pm}6.89$ days) service period was (highest) in parity number one and lowest in parity number eight ($107.95{\pm}19.72$ days). The difference was highly significant. In overall data significantly lower service periods were seen in buffaloes calving in spring+winter as compared to summer+fall.

A preliminary study of prehistoric tunnel-dwelling sites and rock-shelters in Che-Ju Island, Korea (제주도지방의 선사문화와 동굴${\cdot}$바위 그늘 주거지)

  • Lee, Chung-Kyu;Kang, Chang-Wha
    • The Korean Journal of Quaternary Research
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    • v.1 no.1
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    • pp.47-67
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    • 1987
  • Geologically speaking, many lava tunnels and caves are characteristic geomorphic features in Che-Ju Island. Especially, cave-ins are found along cliffs of shoreline and streams. The prehistoric early inhabitants in the island used the tunnels and cave-ins as their major shelters from palaeolithic period to the iron period (AD300-600). These tunnel-dwelling sites and rock-shelters are unsidered to be long-term shelters from the palaeolithic period to the neolithic period. However, these shelters and sites might be changed as temporary camping sites from the bronze to the iron period.

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Factors Influencing on Use of Complementary.Alternative Therapy on Chronic Patients (만성질환자의 보완대체요법 이용에 영향을 미치는 요인)

  • Park, Hyeon-Shin;Hyun, Kyung-Sun
    • Journal of East-West Nursing Research
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    • v.17 no.1
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    • pp.1-8
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    • 2011
  • Purpose: The purpose of this study was to identify influencing factors of using numbers and period of complementary and alternative therapy (CAT) among chronic patients. Methods: The study employed a descriptive design. The participants were 221 chronic patients. Data were collected in a pharmacy near a general hospital from April to July, 2008. Results: Influencing factors on using number of CAT were age, numbers of disease, period of used CAT and monthly expenses on CAT (the ability to explain, 79.9%). Influencing factors on using period of CAT were the period of illness and using number of CAT (the ability to explain, 44.9%). Conclusion: The results of this study suggest that chronic patients need counseling and guides about using CAT especially for those are older and have many kinds and longer period of diseases.

IT SME Ventures' External Information Network Diversity and Productivity Improvement : The Mediating Role of the Production Period Reduction (IT 중소벤처기업의 외부 정보 네트워크의 다양성과 생산성 향상 : 생산 기간 단축의 매개적 역할)

  • Hau, Yong Sauk
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.1
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    • pp.144-149
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    • 2017
  • This study empirically analyzes the effect of IT SME ventures' external information network diversity on their production period reduction and productivity improvement generated from technology development. This research constructs a mediating model based on the open innovation perspective and tests it with the 138 samples of South Korean IT SME ventures based on the ordinary least squares regression. This research is expected to make a good contribution by shedding a new light on the following three points about the critical role of IT SME ventures' external information network diversity in increasing their production period reduction and productivity improvement generated from technology development which has scarcely been illuminated in the extant studies in the field of the management of technology for SMEs. First, IT SME ventures' external information network diversity positively influences their production period reduction. Second, the external information network diversity positively influences IT SMEs' ventures' productivity improvement. Third, IT SME ventures' production period reduction partially mediates the influence of IT SME ventures' external network diversity on their productivity improvement. These three fresh points are expected to provide useful theoretical and practical implications. Related to the theoretical implication, this research provides a fresh implication that IT SME ventures' external information network diversity positively influences not only their production period reduction but also productivity improvement generated from technology development. Concerning the practical implication, this study suggests that the CEOs in IT SME ventures make strategic efforts to use more diverse external information sources in order to increase their production period reduction and productivity improvement generated from technology development.

The Transition of Late 18th Century Women's Costume and Enlightenment, with Reviewing the Portraiture of Marie Antoinette - Focused on 1770-1793 - (Marie Antoinette의 초상화를 통해 본 18세기 후기 여성 복식의 변화와 계몽주의 사상 - 1770-1793을 중심으로 -)

  • Bae, Soo-Jeong
    • Journal of the Korean Society of Costume
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    • v.62 no.1
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    • pp.120-136
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    • 2012
  • This thesis takes an aim to investigate the relationship between the costume and enlightenment ideology by studying the change of costume, and reviewing the portraiture of Queen Marie Antoinette. The method of this research is to select the 29 pieces among the portraitures from 1770 to 1793, and to analyze the headdress, shape of robes and ornaments. The results are as follows. The first period(1770-1774): The costume in this period of Dauphin of France is described as vivid, and simple like her characters, and also represents her active lifestyle. The ideology of equality between the two sexes from the enlightenment slightly influence the costumes seen inside the portrait of Dauphin. The second period (1775-1779): This is the early period of the Queen's enthronement and also before her childbirth. The relatively small number of portraits showed her as an authoritative figure because her skirts were expanded with huge panier, the waist were tightened with corset, and her headdress was enlarged. Thus, this period could not be defined as the one of enlightenment philosophies in light of the persistent unsanitary construction of costumes distorting the body. The third period(1780-1789): There are many portraits depicting the Queen and her children. It is noteworthy that the English style picturesque garden was illustrated as a background while the costume was simple and sanitary, both being affected by the enlightenment. The last period(1789-1793): This is the period between the French revolution and the death of the Queen. The form of costumes was transformed into the neoclassic style, headdress was reduced in size, and was simplified as a result of complete change of costume for the enlightenment. This research is to be interpreted as a tool of study about the relationship of costume, society and ideological streams and also be a means of elucidating the contemporary times in view of the past ones.