• 제목/요약/키워드: stability period

검색결과 1,550건 처리시간 0.028초

수산기업의 부실화 요인과 그 예측에 관한 연구 (A Study on the Distress Prediction in the Fishery Industry)

  • 장창익;이윤원;홍재범
    • 수산경영론집
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    • 제39권2호
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    • pp.61-79
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    • 2008
  • The objectives of this paper are to identify the causes of the corporate distress and to develop a distress prediction model with the financial information in fishery industry. In this study, the corporate distress is defined as economic failure and technical insolvency. Economic failure occurs by reduction, shut - down, or change of the business and technical insolvency results from failure to pay the financial debt of companies. The 33 distressed firms from 1991 to 2003 were composed by 14 economic failure companies, 15 technical insolvency companies. 4 companies applied to the both cases. The analysis of distress prediction of fishery companies were accomplished according to the distress definition. The analysis was carried out as two steps. The first step was the univariate analysis, which was used for checking the prediction power of individual financial variable. The t - test is used to identify the differences in financial variables between the distressed group and the non - distressed group. The second step was to develop distress prediction model with logistic regression. The variables showed the significant difference in univariate analysis were selected as the prediction variables. The financial ratios, used in the logistic regression model, were selected by backward elimination method. To test stability of the distress prediction model, the whole sample was divided as three sub-samples, period 1(1990 - 1993), period 2(1994 - 1997), period 3(1998 - 2002). The final model built from whole sample appled each three sub - samples. The results of the logistic analysis were as follows. the growth, profitability, stability ratios showed the significant effect on the distress. the some different result was found in the sub - sample (economic failure and technical insolvency). The growth and the profitability were important to predict the economic failure. The profitability and the activity were important to predict technical insolvency. It means that profitability is the really important factor to the fishery companies.

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남극해 인도양 해역에 위치한 콘래드 해령 지역의 마지막 빙하기 이후 생물기원 오팔 생산의 변화 (Variation of Biogenic Opal Production on the Conrad Rise in the Indian Sector of the Southern Ocean since the Last Glacial Period)

  • 양주연;;최혁;김부근
    • Ocean and Polar Research
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    • 제45권3호
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    • pp.141-153
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    • 2023
  • Biological pump processes generated by diatom production in the surface water of the Southern Ocean play an important role in exchanging CO2 gas between the atmosphere and ocean. In this study, the biogenic opal content of the sediments was measured to elucidate the variation in the primary production of diatoms in the surface water of the Southern Ocean since the last glacial period. A piston core (COR-1bPC) was collected from the Conrad Rise, which is located in the Indian sector of the Southern Ocean. The sediments were mainly composed of siliceous ooze, and sediment lightness increased and magnetic susceptibility decreased in an upward direction. The biogenic opal content was low (38.9%) during the last glacial period and high (73.4%) during the Holocene, showing a similar variation to that of Antarctic ice core ΔT and CO2 concentration. In addition, the variation of biogenic opal content in core COR-1bPC is consistent with previous results reported in the Antarctic Zone, south of the Antarctic Polar Front, in the Southern Ocean. The glacial-interglacial biogenic opal production was influenced by the extent of sea ice coverage and degree of water column stability. During the last glacial period, the diatom production was reduced due to the penetration of light being limited in the euphotic zone by the extended sea ice coverage caused by the lowered seawater temperature. In addition, the formation of a strong thermocline in more extensive areas of sea ice coverage led to stronger water column stability, resulting in reduced diatom production due to the reduction in the supply of nutrient-rich subsurface water caused by a decrease in upwelling intensity. Under such environmental circumstances, diatom productivity decreased in the Antarctic Zone during the last glacial period, but the biogenic opal content increased rapidly under warming conditions with the onset of deglaciation.

폐기물매립지의 사후관리종료 평가를 위한 안정화 지수 산정에 관한 연구 (Development of Stability Index for Defining the End of the Post-closure Monitoring Period for MSW Landfill)

  • 이남훈;한정현
    • 유기물자원화
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    • 제14권2호
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    • pp.63-70
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    • 2006
  • 본 연구에서는 폐기물매립지의 안정화 정도를 용이하게 평가하기 위하여 매립폐기물의 분해정도를 수치화 할 수 있는 매립지의 안정화 지수 개발을 목적으로 하였다. 안정화 지수를 개발하기 위하여 50개소의 사용종료 매립지를 대상으로 침출수 수질, 매립가스 조성, 매립폐기물의 물리화학적 특성 자료를 수집하여 이들의 매립연령별 환경특성을 고찰하였다. 그리고 이들 환경지표중 폐기물매립지의 안정화와 상관도가 높은세부 환경지표로서 침출수의 BOD/CODcr, 발생가스중의 $CH_4$농도, 매립폐기물의 C/N가 안정화 지표로 선정하였다. 각 지표에 대한 매립연령별 추세선을 이용하여 지수화한 결과 매립지 안정화 지수로 다음과 같은 식을 얻을 수 있었다. $$I_{LS}=S_L+S_G+S_W$$ $$S_L=-\{4.892+16.587{\cdot}ln[BOD/COD_{Cr]\}$$ $$S_G=53.872-12.782{\cdot}ln[CH_4]$$ $$S_W=79.382-20.013{\cdot}ln[C/N]$$ (단, $S_L$, $S_G$, and $S_W$는 각각 33.3점이 최대값이다.) 여기서, $I_{LS}$ : 매립지 안정화 지수 $S_L$ : 침출수의 안정화 점수 $S_G$ : 매립가스의 안정화 점수 $S_W$ : 폐기물의 안정화 점수.

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된장분말을 첨가한 두유마요네즈와 일반마요네즈의 저장안정성 비교 (Comparison of Storage Stability between Soy Milk Mayonnaise and Mayonnaise contained Soybean Paste Powder)

  • 박혜덕;이상선
    • 한국식품위생안전성학회지
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    • 제24권3호
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    • pp.247-255
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    • 2009
  • 마요네즈 제조 시 유화제로 사용되고 있는 난황이 콜레스테롤을 다량 함유하고 있는 점을 개선하기 위하여 난황 대신 두유를 사용하였고, 된장의 항산화 효과로 인해 마요네즈의 저장성을 증진시켜줄 수 있을 것이라는 점에 착안하여 된장분말을 첨가하여 마요네즈를 제조한 후 유화제 종류와 된장분말의 첨가가 마요네즈의 품질 및 저장성을 향상시킬 수 있는지 조사하고자 연구를 시행하였고, 그 결과는 다음과 같다. 1. 과산화물가, TBA가, 산가는 저장기간 동안 점차 증가하였다(p < 0.001). 과산화물가는 66배$\sim$140배, TBA가와 산가는 2배$\sim$3배의 증가를 보였다. 된장분말의 첨가량이 증가할수록 과산화물가, TBA가, 산가의 증가가 적은 것으로 나타났다(p < 0.001). 2. 탁도는 초기에 E3와 S3에서 높게 나타났다. E군은 S군보다 탁도가 높았고, 된장분말의 첨가량이 높을수록 탁도는 높게 나타났으며, 저장기간에 따라 감소하였다(p < 0.001). 3.점도는 E군이 S군보다 높았고, 된장분말의 농도가 증가할수록 점도도 증가하였다. E3에서 $65.18{\times}10^3\;cp$로 가장 높은 점도를 나타내었으며, S1에서 $19.19{\times}10^3\;cp$로 가장 낮은 점도를 나타냈다. 된장분말의 첨가량은 저장기간에 따른 점도의 감소를 지연시키는 것으로 나타났다(p < 0.001). 연구 결과를 종합해 보면 된장분말의 첨가에 의해 마요네즈 저장 중의 산화안정성이 향상되었고, 점도 감소율도 낮아졌다. 따라서 된장분말을 첨가하고 두유로 제조한 마요네즈는 저장성을 향상시켜 품질개선에 기여할 수 있을 것으로 사료된다.

볶음조건에 따른 포도씨유의 산화안정성 (Oxidative Stability of Grape Seed Oils Under Different Roasting Conditions)

  • 장성호;이선미;정헌상;이준수
    • 한국식품영양과학회지
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    • 제39권11호
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    • pp.1715-1718
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    • 2010
  • 본 연구에서는 볶음조건에 따른 포도씨유의 산화안정성을 알아보고자 하였다. 포도씨를 100, 150, $200^{\circ}C$에서 1시간 볶은 후, hexane으로 추출 후 용매를 제거하여 얻은 포도씨유를 $50^{\circ}C$에서 40일 동안 저장하였다. 과산화물가는 저장기간 동안에 볶음처리를 하지 않은 포도씨유에서 볶음처리한 포도씨유보다 높은 함량을 보였다. 산가 또한 비슷한 경향을 보였다. 포도씨유의 갈색도는 볶음온도가 높을수록 짙은 갈색을 띄는 것을 알 수 있었다. 비타민 E의 함량은 저장기간에 따라 감소하는 경향을 보였지만, 볶음온도가 높을수록 비타민 E의 함량이 높게 나타났으며, 비타민 E 이성체의 감소량도 적게 나타났다. 따라서 본 연구는 볶음온도에 따른 포도씨유의 산화안정성 평가의 기초자료로 활용될 수 있을 것으로 기대한다.

석산개발 지역 퇴적장 석축사면의 안정성 해석 (Analysis of Slope Stability of Masonry Retaining Walls in Quarry)

  • 마호섭;이성재
    • 한국산림과학회지
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    • 제107권4호
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    • pp.385-392
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    • 2018
  • 석산개발 지역 퇴적장 석축사면의 사면 조성 및 관리기술 증진을 위하여 현황측량을 실시하고, 대표단면을 선정하여 사면의 안정성 해석을 수행한 결과를 요약하면 다음과 같다. 사면안정 해석을 위하여 선정한 대표단면의 퇴적장 최하단부 사면(A) 경사는 $59^{\circ}$로서 급경사를 이루고 있으나, 전체 퇴적장 사면(A, B, C, D, E, F)의 평균경사는 $38.5^{\circ}$이었다. 퇴적장 사면의 수평거리는 총 66.2 m, 사면높이는 48.3 m이지만 퇴적장 석축사면의 경사는 비교적 급하며, 시각적으로도 불안정해 보인다. 사면안정 해석에는 건조시와 포화시를 고려하였으며 포화시의 사면안정 해석은 대상사면이 완전히 포화된 상태를 모델링하여 수행하였다. 지반의 강도정수는 석축과 배면지반으로 구분하고 안전성을 검토하였다. 건기시 안전율은 1.850, 우기시 안전율은 1.333으로 나타나 건기시 및 우기시의 안전율 1.5와 1.2를 상회하여 사면의 활동에 대하여 모두 안전한 것으로 나타났다. 그러나 집중호우 시 퇴적장 사면 상부의 풍화된 마사토는 사면침식과 붕괴 위험성이 높아 배수로 설치 등 적절한 유지관리를 통한 안정대책이 필요하다고 생각된다.

국내산 아피오스의 수확시기와 증자처리에 따른 품질 및 항산화 특성 (Quality and Antioxidant Characteristics according to Different Harvest Periods and Steaming Treatment of Apios (Apios americana Medikus) Cultivated in Korea)

  • 황엄지;김세희;김현주;정재희;이영훈;하태정;우관식
    • 한국식품영양학회지
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    • 제35권6호
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    • pp.445-452
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    • 2022
  • The quality and antioxidant characteristics of apios (Apios americana Medikus) according to different harvest periods and steaming treatment were investigated. The quality and antioxidant characteristics of apios were significantly different depending on harvest periods. Total starch contents was higher in 1st harvesting period as 62.32 g/100 g than other harvesting period. The water binding capacity and water solubility index was higher in 1st harvesting period as 228.65 and 11.29% than other harvesting period. The sucrose and total free sugar contents were 3.64~8.67 and 4.49~9.54 g/100 g, respectively. Total polyphenol and flavonoid contents of apios was the highest 2nd and 4th harvesting period at 4.21 mg GAE/g and 611.11 ㎍ CE/g, respectively. DPPH radical scavenging activity was higher in 1st harvesting period as 84.96 mg TE/100 g than other harvesting period, and decreased as the harvest periods were delayed. ABTS radical scavenging activity and ferric-reducing antioxidant power were 43.81~47.89 mg TE/g and 231.20~264.07 mM/100 g, and increased to 50.58~51.44 mg TE/g and 342.55~384.29 mM/100 g after heat treatment. As a result, it is thought that studies on change of quality and physicochemical characteristics according to cultivation characteristics should be preceded for cultivation stability of apios.

Retrospective clinical study of ultrawide implants more than 6 mm in diameter

  • Ku, Jeong-Kui;Yi, Yang-Jin;Yun, Pil-Young;Kim, Young-Kyun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제38권
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    • pp.30.1-30.6
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    • 2016
  • Background: The prognosis of wide implants tends to be controversial. While wider implants were initially expected to result in a larger osseointegration area and have higher levels of primary stability, they were reported to have a relatively high rate of failure. The clinical outcome of ultrawide implants of more than 6 mm in diameter was evaluated through a retrospective study. Methods: The investigation was conducted on patients who had received ultrawide implant (${\geq}6mm$ diameter) placements in Seoul National University Bundang Hospital from January 2008 to December 2013. Complications were investigated during the maintenance period, and marginal bone loss was measured using periapical radiography. Primary stability immediately after the implant placement and second stability after second surgery or during impression were measured using $Osstell^{(R)}$ Mentor (Osstell, Sweden) as an implant stability quotient (ISQ). Results: Fifty-eight implants were placed in 53 patients (30 male, 23 female), and they were observed for an average of $50.06{\pm}23.49$ months. The average ISQ value increased from $71.22{\pm}10.26$ to $77.48{\pm}8.98$ (P < 0.005). The primary and secondary stability shows significantly higher at the mandible than at the maxilla (P < 0.001). However, mean survival rate shows 98.28 %. Average marginal bone loss of 0.018 and 0.045 mm were measured at 12 and 24 months after the loading and 0.14 mm at final follow-up date (mean 46.25 months), respectively. Also in this study, the bone loss amount was noticeably small compared to regular implants reported in previous studies. Conclusions: The excellent clinical outcome of ultrawide implants was confirmed. It was determined that an ultrawide implant can be used as an alternative when the bone quality in the posterior teeth is relatively low or when a previous implant has failed.

Mandibular arch orthodontic treatment stability using passive self-ligating and conventional systems in adults: A randomized controlled trial

  • Rahman, Norma Ab;Wey, Mang Chek;Othman, Siti Adibah
    • 대한치과교정학회지
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    • 제47권1호
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    • pp.11-20
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    • 2017
  • Objective: This randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention. Methods: Forty-seven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age $21.58{\pm}2.94years$) were randomized into two groups to receive either passive self-ligating ($Damon^{(R)}$ 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis. Results: A significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant. Conclusions: The stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention.

Analyses on Thermal Stability and Structural Integrity of the Improved Disposal Systems for Spent Nuclear Fuels in Korea

  • Lee, Jongyoul;Kim, Hyeona;Kim, Inyoung;Choi, Heuijoo;Cho, Dongkeun
    • 방사성폐기물학회지
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    • 제18권spc호
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    • pp.21-36
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    • 2020
  • With respect to spent nuclear fuels, disposal containers and bentonite buffer blocks in deep geological disposal systems are the primary engineered barrier elements that are required to isolate radioactive toxicity for a long period of time and delay the leakage of radio nuclides such that they do not affect human and natural environments. Therefore, the thermal stability of the bentonite buffer and structural integrity of the disposal container are essential factors for maintaining the safety of a deep geological disposal system. The most important requirement in the design of such a system involves ensuring that the temperature of the buffer does not exceed 100℃ because of the decay heat emitted from high-level wastes loaded in the disposal container. In addition, the disposal containers should maintain structural integrity under loads, such as hydraulic pressure, at an underground depth of 500 m and swelling pressure of the bentonite buffer. In this study, we analyzed the thermal stability and structural integrity in a deep geological disposal environment of the improved deep geological disposal systems for domestic light-water and heavy-water reactor types of spent nuclear fuels, which were considered to be subject to direct disposal. The results of the thermal stability and structural integrity assessments indicated that the improved disposal systems for each type of spent nuclear fuel satisfied the temperature limit requirement (< 100℃) of the disposal system, and the disposal containers were observed to maintain their integrity with a safety ratio of 2.0 or higher in the environment of deep disposal.