• Title/Summary/Keyword: stability period

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A Study on the Stability of Using Alkali Solution Desalination on Gilt Plated Silver-Iron Artifacts (알칼리 수용액을 이용한 출토 철지금은장관정의 탈염처리 적용성 평가)

  • Park, Jun Hyeon;Bae, Go Woon;Chung, Kwang Yong
    • Journal of Conservation Science
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    • v.37 no.2
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    • pp.179-189
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    • 2021
  • In this study, the research objects are gilt plated silver-iron nails excavated from the west of the tombs in Neungsan-ri, Buyeo. A gilt plated silver-iron nail was fabricated by combining silver and iron via heating and then gilding amalgam on top of this combination, demonstrating that this ancient artifact that can be replicated using current technology. Since the metal (Au, Ag) surface of these gilt plated artifacts are covered with iron oxide, which slips into the cracks and scratches of the artifacts as well, desalination is essential. Based on the results of the preliminary experiment, the research objects were classified into grades A, B, and C, according to the degree of corrosion and then desalinated using an alkali solution (NaOH, Sodium Sesquicarbonate of 0.1 M) at 60℃. The results demonstrate that the more serious is the degree of corrosion, the more is the amount of Cl- detected. Further, more Cl- was released when NaOH was used than when sodium sesquicarbonate was used, for all grades except Grade A. Furthermore, the more serious is the degree of corrosion, the longer is the desalination period and the reaction with NaOH for all grades except Grade A. A comparison of the Fe composition of the surface before and after desalination shows that Fe composition is the use of NaOH resulted in a smaller increase compared with the use of sodium sesquicarbonate, for all grades except Grade B. However, four of the nails were damaged owing to NaOH (Grade B 3ea, Grade C 1ea) during desalination. Thus, Cl- ions are more stably released when sodium sesquicarbonate is used than when NaOH is used.

Trends and Synchronization of Transaction Amounts by Product group of Online Malls in Online Shopping Malls (온라인쇼핑몰에서 Online몰의 상품군별 거래액 동향과 동조화 현상)

  • Choi, Soo-Ho;Choi, Jeong-Il
    • Journal of Digital Convergence
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    • v.19 no.2
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    • pp.151-160
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    • 2021
  • The purpose of this study is to classify online shopping malls into total transaction amount and transaction amount by product, and compare them to find synchronism. The data used in this study were collected from KOSIS for Food Services, Home Appliances·Electronics·Communication devices, Food & Beverages, House_Goods, Clothing, Computers & Peripheral Devices. The analysis period is a total of 44 monthly data from January 2017 to August 2020. In descriptive statistics, variability is relatively very stable in the case of food service, but is large in the case of clothing. In the correlation analysis, the total transaction amount shows a certain level of correlation with each product. In the analysis of the increase rate, Food Service increased by 1,039%, Home Appliances·Electronics·Communication devices increased by 325%, Food & Beverages increased by 296% and House Goods by 250%, but Clothing decreased slightly to 92.56%. In the Scatter Charts analysis, the distribution of Total transaction amount & House Goods, Total transaction amount & Home Appliances·Electronics·Communication devices is generally upward, showing a high level of synchronization. Due to Corona 19, we will have to continue our efforts to provide speed, stability, convenience and various services in preparation for the increase in transaction volume of online shopping malls.

A Study on the Determination of Indicators for the Risk Assessment of Ground Depression Using SAR Imageson (SAR 영상을 활용한 지반침하의 위험평가를 위한 지표결정에 대한 연구)

  • Lee, Hyojin;Yoon, Hongsic;Han, Hak
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.7
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    • pp.13-20
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    • 2021
  • The problem of subsidence of the roadbed near the Honam High Speed Railway, which opened in April 2015, continues to be raised, and the ground stability of the area near the Honam High Speed Railway may also be problematic. It is very important to select the factors that determine the indicators and indicators in producing the risk maps. Existing risk indicators are calculated as the final displacement volume based on the last observed date of the observed period, and time-series indicator displacement must be identified to analyze the cause of subsidence and the behavior of the indicator. Furthermore, for a wide range of regions, it is economically inefficient to conduct direct level measurements, so we wanted to observe surface displacement using SAR images. In this paper, time series indicator displacement was observed using PS-InSAR techniques, and risk was compared by rating each factor using the difference between final indicator displacement, cumulative indicator displacement, minimum displacement and maximum displacement as factors for determining risk indicators. As a result, the risk rating of the final displacement is different from that of each factor, and we propose adding factors from different perspectives in determining risk indicators. It is expected to be an important study in finding the cause of ground subsidence and finding solutions.

The First Year of the Moon Jae-In Government: An Assessment (문재인 정부 1년의 평가와 전망)

  • Kang, Won-Taek
    • Korean Journal of Legislative Studies
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    • v.24 no.1
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    • pp.5-29
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    • 2018
  • This paper aims at making an assessment about the first year of the Moon Jae-in government. President Moon was elected amid political insecurity over the impeachment of then-president Park Geun-hye. However, the Moon administration settled in fairly smoothly despite no transition period of presidential power. Political and economic stability was soon restored, and the tensions between the US and North Korea over the North's nuclear weapons program were, to some extent, managed along with the agreement of the North-South summit and the US-North Korea summit. Pyeongchang hosted the 2018 winter olympics and paralympics successfully. Moon continued very positive approval ratings of higher than 70%. However, he has something to be desired. His leadership seems to rely heavily on a limited number of close staff in the Blue House, alienating the governing the Minjoo Party of Korea. He should build better relationship with opposition parties particularly given a divided government. Rectification of the lingering negative practices should also produce institutional solutions. Above all, Moon should carefully watch out to prevent scandals over corruption and power abuse around him and his family, which would lead to a precipitous decline of the approval ratings and the abrupt weakening of the leadership.

The Theory of Yin and Yang and the Five Elements of Mohism - Focusing on the Comparison with Hundred Schools of Thought (묵가(墨家)의 음양오행론(陰陽五行論) - 제가(諸家)와의 비교를 중심으로 -)

  • Yun, Muhak;Cho, Jueun
    • The Journal of Korean Philosophical History
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    • no.38
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    • pp.189-220
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    • 2013
  • In this paper, the discussion on Yin and Yang and the Five Elements in Mohism is examined through the comparison with Hundred Schools of Thought. The ideas of School of Naturalists including Zou Yan or those of the Five Elements were fundamentally for the purpose of observing the regularity of changing dynasty. However, this perspective had not been emphasized as a subject of Contention of a Hundred Schools of Thought until the end of the Era of Warring States. Even though it is true that Hundred Schools of Thought applied the theory of Yin and Yang and the Five Elements in common based on the understanding of the idea, but it failed to be connected to each ideological system. The fundamental reason for this can be found in the difference between the awareness of a reality and the concept of history in Hundred Schools of Thought. Where were the characteristics and reasonable opinions of the theory of Yin and Yang and the Five Elements in Mohism from? The most important feature of Mohism is to form independent, collective, cooperative groups based on the people of lower classes at that time and to consider God an ideological presumption. Therefore, in reality, it concentrated only on sociopolitical stability and maintenance of their own labor activities, and it was difficult for them to focus on an objective regularity of a national system or change of dynasty. In addition, due to the characteristics of individual groups, it was hard to have a macroscopic viewpoint not only on a national system, but also on others as in Zou Yan's Dae-gu-ju-seol(大九州說). With respect to this, at least, Xunzi, before the unification, gives a valid criticism. In the end, the effort to design a new political system and to secure ideological legitimacy on the assumption of the unification of the nations of the Warring States period became more specific through the edition of $L{\ddot{u}}shi$ Chunqiu (呂氏春秋), so-called Mixed School(雜家) or Synthesized School(綜合家).

Implementaion Mechanism of Homepage Failure Notification System in Public Sector in IDC Environment (IDC환경에서 공공부문 홈페이지 장애상황공지 시스템 구축방안)

  • Kim, Yong-Tae;Jo, In-June
    • The Journal of the Korea Contents Association
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    • v.21 no.1
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    • pp.426-433
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    • 2021
  • Investment in public sector information services has been on the rise in recent years. The supply of high-speed Internet and smartphones has become more common, and the stability of the information system provided to the public in the public sector has become an important management factor. In other words, tasks such as handling civil complaints and issuing certificates by public institutions, financial transactions by banks, customs clearance work, and e-commerce by individuals or institutions are mostly done online. Therefore, how to deal with obstacles arising from the information system, which is in charge of important civil service affairs, is becoming a very important issue. In other words, in the case of a disability that does not function normally even for a short period of time, various problems can occur when the work is delayed, as well as causing serious financial damage to the civil petitioner. This could be accompanied by a decline in public confidence and various other damages such as filing civil complaints. The reasons for the occurrence of information system failures are very diverse and realistically difficult to predict when. Among the various measures to cope with disability, this paper proposed a plan to establish a disability situation notification system that can minimize confusion caused by disability in the event of a homepage malfunction. The proposed disability situation notification system was established in the public IDC environment to show the possibility of utilization.

Evaluation of Field Applicability of Slope of Improved Soil for Ground Stabilizer (지반안정재 개량토의 토사 비탈면 현장 적용성 평가)

  • Lee, Kang-Il;Park, Seong-Bak;Choi, Min-Ju
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.1
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    • pp.35-44
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    • 2021
  • This research studies the stabilization method for improved soil sloped through the on-site application of Paper Flyash ground stabilizers. The target strength required for improved soil is 500 kPa, and the compressive strength for the slope surface needs to be less than 1,000 kPa after the improvement in order to plant vegetation. To meet this condition, we mixed soil from the site and the ground stabilization material, which is the main material for surface improvement material, performed mixing design and conducted various tests including strength test, permeability test and plantation test. After analyzing the results of the compression test on improved soil slope, we proposed soil constants for the improved soil. In order to evaluate the applicability of the improved soil on the slope, the site construction was carried out on the collapsed slope and the reinforcement evaluation of the surface of the improvement soil was conducted. The stability was not secured before the reinforcement, but the test shows after the reinforcement with improved soil, the safety rate is secured up to 48 hours during the raining period. In addition, the compressive strength of the improved soil at the site was secured at more than 200 kPa adhesion as planned, and the soil hardness test result was also found to be within the specified value of 18-23 mm, which increased the resistance to rainfall and ability to grow plant on the surface for improved soil.

Performance Assessment of Navigation Seakeeping for Coastal Liquified-Natural-Gas Bunkering Ship (연안선박용 LNG 벙커링 전용선박의 내항성능 평가에 대한 연구)

  • Yi, Minah;Park, Jun-Bum;Lee, Chang-Hee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.7
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    • pp.904-914
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    • 2020
  • Through the Ministry of Trade, Industry, and Energy, South Korea is trying to support the "Building Project for Liquified Natural Gas (LNG) Bunkering Ship," centered on the Korea Gas Corporation, while the Ministry of Maritime Af airs and Fisheries is pushing to construct an LNG bunkering terminal at Busan New Port. LNG bunkering ships are essential for supplying LNG fuel from the terminal to the ships, resulting in the need for safety operation procedures. Therefore, in this study, the stability of a coastal LNG bunkering ship operating from Busan New Port to the anchorage in Busan Port was assessed to investigate the need for operational procedures for coastal LNG bunkering ships. Seakeeping analysis of the LNG bunkering ship was performed for each significant wave height by combining the response amplitude operator from the ship motion analysis under the potential flow theory with the actual observed sea data for five years and Texel, Marsen, and Arsloe (TMA) spectrum suitable for the Busan coast. The results showed that the roll and horizontal acceleration were the main risks that affected the navigation seakeeping performance above a significance wave height of 2 m. The operational periods of the LNG bunkering ship ranged from 83.3% to 99.9% of the total observation period.

A Study on Animal Skin Irritation Measurement of Ozoneized Olive Oil for Cosmetic Ingredients (화장품원료를 위한 오존화 올리브오일의 동물 피부자극 측정에 관한 연구)

  • Kim, Ducksool
    • Journal of the Institute of Convergence Signal Processing
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    • v.22 no.1
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    • pp.14-19
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    • 2021
  • This study has attempted to use ozone for the treatment of skin diseases as research results that ozonated olive oil has an excellent therapeutic effect on skin diseases are known. However, there is hardly any accurate data in Korea. Usually, animal tests related to cosmetics are not performed, but toxicity tests were conducted because they were absolutely necessary. In general, there are not many cases of measuring actual data through animal tests for the purpose of confirming the performance of cosmetics, but in the case of toxicity tests, it is recommended to accurately measure skin reactions, so this experiment was conducted. In this experiment, in order to evaluate the skin irritation of ozonated oil (high concentration) on the rabbit, the test substance was applied to the back of the rabbit for 24 hours, and then mortality, general symptoms and skin irritation were evaluated. Experimental Results As a result of evaluating the treatment site of the test substance after a certain period of time, no skin irritation was observed in all animals.

A Preliminary Study on Family Function Components Affecting Individual Health and Disease: A Delphi Study (개인의 건강과 질병에 영향을 미치는 가족기능 구성요소에 관한 사전연구: 델파이 연구)

  • Kim, Ah-Ram;Jeong, Seong-Woo;Jeong, Jiin;Kim, Jung-Ran
    • Therapeutic Science for Rehabilitation
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    • v.10 no.3
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    • pp.83-96
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    • 2021
  • Objective : This study aimed to determine Korea-type family function factors that affect individual growth and social activities, and examine check the appropriate contents and domestic culture components based on the McMaster model, a family function evaluation tool, through the Delphi technique. Methods : The Delphi technique was applied to 12 expert panels in fields related to family function. The period lasted 9 weeks, from May to June 2020. The Delphi survey was conducted twice. In the first survey, the domestic culture and appropriate contents of the McMaster model were selected and localized, and expert' opinions about the components were collected using closed and open-ended questions. In the second survey, the fitness and importance of the components were investigated. Results : As a result of the first Delphi investigation, 18 items were deleted from the 53 items presented. After adding 11 items and excluding any overlapping items, a total of 40 items were selected. Subsequently, sentences that were difficult to understand were revised to familiar vocabulary. A second survey was constructed, with an example sentence. In the second Delphi investigation, 33 items were selected. The average content validity ratio for the final selected component was 0.76, and the stability was 0.28. Conclusion : Family function and the factors influencing domestic family function identified though this study can be used to conduct family function evaluations and interventions in clinical sites or relevant research studies.