• Title/Summary/Keyword: 신뢰도 모델

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A Study on the Accelerated Life Test for the Estimation of Licorice Durability in Cosmetics (화장품 중 유용성감초추출물의 유통기한 예측을 위한 가속수명 시험연구)

  • Lee, So-Mi;Joo, Kyeong-Mi;Park, Jong-Eun;Jeong, Hye-Jin;Chang, Ih-Seop
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.33 no.3
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    • pp.197-201
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    • 2007
  • Oil soluble licorice extract(licorice extract) is an officially approved cosmetic component as a whitening ingredient in Korea. The durability of licorice, during which the whitening effect can be maintained in optimum condition, must be accurately defined. Since the cosmetics durability under real condition is relatively longer than its development time. It is needed to predict the real durability interval from the experimental measurement under simulated operating conditions. We analyzed the relationship between the licorice lifetime and the high temperature condition by using Arrhenius equation. We have established the constant stress test with temperature of $50^{\circ}C$, $55^{\circ}C$, and $60^{\circ}C$ condition, within which no formulation change of licorice products is expected for the accelerated stress test. In this paper, the lifetime of licorice in cosmetics was defined as time period for its 10% contents reduction. We observed that the lifetime of licorice is 580 h at $50^{\circ}C$, 319 h at $55^{\circ}C$ and 166 h at $60^{\circ}C$. Using the above experimental data, we obtained the equation for the relationship between the licorice lifetime and temperature as follows; log(lifetime)=-35.0243 + 1.15322$\times$(11604.83/temperature). From this equation, the lifetime of licorice at $25^{\circ}C$ can be estimated as 26 months. The estimated result was verified by measuring full lifetime of licorice. In fact, there was no significant difference between the estimated lifetime and real measurement within 95 % significance level. This study can be applied to other useful cosmetic components for the fast estimation of the exact durability.

An Evaluation of the Private Security Industry Regulations in Queensland : A Critique (호주 민간시큐리티 산업의 비판적 고찰 : 퀸즐랜드주를 중심으로)

  • Kim, Dae-Woon;Jung, Yook-Sang
    • Korean Security Journal
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    • no.44
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    • pp.7-35
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    • 2015
  • The objective of this article is to inform and document the contemporary development of the private security industry in Queensland Australia, a premier holiday destination that provide entertainment for the larger region. The purpose of this review is to examine the comtemporary development of mandated licensing regimes regulating the industry, and the necessary reform agenda. The overall aim is threefold: first, to chart the main outcomes of the two-wave of reforms since the mid-'90s; second, to examine the effectiveness of changes in modes of regulation; and third, to identify the criteria that can be considered a best practice based on Button(2012) and Prenzler and Sarre's(2014) criteria. The survey of the Queensland regulatory regime has demonstrated that, despite the federal-guided reforms, there remain key areas where further initiatives remain pending, markedly case-by-case utilisation of more proactive strategies such as on-site alcohol/drug testing, psychological evaluations, and checks on close associates; lack of binding training arrangement for technical services providers; and targeted auditing of licensed premises and the vicinity of venues by the Office of Fair Trading, a licensing authority. The study has highlighted the need for more determined responses and active engagements in these priority areas. This study of the development of the licensing regimes in Queensland Australia provides useful insights for other jurisdictions including South Korea on how to better manage licensing system, including the measures required to assure an adequate level of professional competence in the industry. It should be noted that implementing a consistency in delivery mode and assessment in training was the strategic imperative for the Australian authority to intervene in the industry as part of stimulating police-private partnerships. Of particular note, competency elements have conventionally been given a low priority in South Korea, as exemplified through the lack of government-sponsored certificate; this is an area South Korean policymakers must assume an active role in implementing accredited scheme, via consulting transnational templates, including Australian qualifications framework.

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Cooling Time Determination of Spent Nuclear Fuel by Detection of Activity Ratio $^{l44}Ce /^{l37}Cs$ (방사능비 $^{l44}Ce /^{l37}Cs$ 검출에 의한 사용후핵연료 냉각기간 결정)

  • Lee, Young-Gil;Eom, Sung-Ho;Ro, Seung-Gy
    • Nuclear Engineering and Technology
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    • v.25 no.2
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    • pp.237-247
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    • 1993
  • Activity ratio of two radioactive primary fission products which had sufficiently different half-lives was expressed as functions of cooling time and irradiation histories in which average burnup, irradiation time, cycle interval time and the dominant fissile material of the spent fuel were included. The gamma-ray spectra of 36 samples from 6 spent PWR fuel assemblies irradiated in Kori unit-1 reactor were obtained by a spectrometric system equipped with a high purity germanium gamma-ray detector. Activity ratio $^{l44}$Ce $^{l37}$Cs, analyzed from each spectrum, was used for the calculation of cooling time. The results show that the radioactive fission products $^{l44}$Ce and $^{l37}$Cs are considered as useful monitors for cooling time determination because the estimated cooling time by detection of activity ratio $^{l44}$Ce $^{l37}$Cs agreed well with the operator declared cooling time within relative difference of $\pm$5 % despite the low counting rate of the gamma-ray of $^{l44}$Ce (about 10$^{-3}$ count per second). For the samples with several different irradiation histories, the determined cooling time by modeled irradiation history showed good agreement with that by known irradiation history within time difference of $\pm$0.5 year. From this result, it would be expected to be possible to estimate reliably the cooling time of spent nuclear fuel without the exact information about irradiation history. The feasibility study on identification of and/or sorting out spent nuclear fuel by applying the technique for cooling time determination was also performed and the result shows that the detection of activity ratio $^{l44}$Ce $^{l37}$Cs by gamma-ray spectrometry would be usefully applicable to certify spent nuclear fuel for the purpose of safeguards and management in a facility in which the samples dismantled or cut from spent fuel assemblies are treated, such as the post irradiation examination facility.mination facility.

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Reevaluation of Lane Width Widenings on Horizontal Curve Sections (평면곡선부 확폭량 재설정에 관한 연구)

  • 최재성;백종대
    • Journal of Korean Society of Transportation
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    • v.18 no.4
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    • pp.51-62
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    • 2000
  • The objective of this study was to reevaluate current Korean design values for lane width widenings on horizontal currie sections and to develop a new method for derivation of design values based on low-speed offtracking. For this purpose, earlier research were reviewed and necessary equations were derived. Also, the method for derivation of widening values of Korea was compared with that for other countries. The result showed that present Korean method could not consider the variation of lane widths and design speeds of roads. In this Paper, to solve such problems, the new concept of widening was developed. That is the current concept of widening which concerns only the dimension of vehicles and radius of curves was replaced by a new concept that lane width widenings on horizontal curve sections is the difference between the width required on curries and tangents. The width required on a curve consists of the swept Path of a vehicle, lateral clearance, and additional allowance. The width of a tangent is calculated by multiplying lane width by the number of lanes The result of applying new concept shows that the values derived from new concept are higher than current design values for curries have same radius. This study was based only on low-speed offtracking. Therefor, it is recommended that further studies which consider the superelevation and high-speed effect on offtracking be made to derive more accurate widening values .

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Site Characterization using Shear-Wave Velocities Inverted from Rayleigh-Wave Dispersion in Chuncheon, Korea (레일리파 분산을 역산하여 구한 횡파속도를 이용한 춘천시의 부지특성)

  • Jung, JinHoon;Kim, Ki Young
    • Geophysics and Geophysical Exploration
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    • v.17 no.1
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    • pp.1-10
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    • 2014
  • To reveal and classify site characteristics in densely populated areas in Chuncheon, Korea, Rayleigh-waves were recorded at 50 sites including four sites in the forest area using four 1-Hz velocity sensors and 24 4.5-Hz vertical geophones during the period of January 2011 to May 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted to derive shear-wave velocity ($v_s$) models comprising 40 horizontal layers of 1-m thickness. Depths to weathered rocks ($D_b$), shear wave velocities of these basement rocks ($v_s^b$), average velocities of the overburden layer ($\bar{v}_s^s$), and the average velocity to a depth of 30 m ($v_s30$), were then derived from those models. The estimated values of $D_b$, $v_s^b$, $\bar{v}_s^s$, and $v_s30$ for 46 sites at lower altitudes were in the ranges of 5 to 29 m, 404 to 561 m/s, 208 to 375 ms/s, and 226 to 583 m/s, respectively. According to the Korean building code for seismic design, the estimated $v_s30$ indicates that the lower altitude areas in Chuncheon are classified as $S_C$ (very dense soil and soft rock) or $S_D$ (stiff soil). To determine adequate proxies for $v_s30$, we compared the computed values with land cover, lithology, topographic slope, and surface elevation at each of the measurement sites. Due to a weak correlation (r = 0.41) between $v_s30$ and elevation, the best proxy of them, applications of this proxy to Chuncheon of a relatively small area seem to be limited.

Changes of the Clinicopathological Characteristics and Survival Rates of Gastric Cancer with Gastrectomy - 1990s vs early 2000s (위절제 위암 환자의 임상병리학적 특성과 생존율의 변화: 1990년대와 2000년대 초기의 비교)

  • Sim, Young-Kwan;Kim, Chan-Young;Jeong, Yeon-Jun;Kim, Jong-Hun;Hwang, Yong;Yang, Doo-Hyun
    • Journal of Gastric Cancer
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    • v.9 no.4
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    • pp.200-206
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    • 2009
  • Purpose: The incidence of upper gastric cancer and especially the diffuse type have increased in western countries. The aim this study was to investigate the chronologic changes of the clinicopathological features and survival rates of Korean upper gastric cancer patients. Materials and Methods: 1,638 gastric cancer patients who underwent gastrectomy were included in this study and they were divided into two groups; the 1990's (1991~1999, n=987) and the early 2000's (2000~2003, n=651). We evaluated the differences of the clinicopathologic features and the factors that affected the survival rates by univariative and multivariative analysis. Results: The older age (>60) patients increased from 42.7% to 50.7% respectively. Being overweight (body mass index$\geq$23) also increased from 31.5% to 43.2%. For the pathology, the incidence of stage Ia gastric cancer increased (29.8% to 44.5%) and the incidence of stage IV gastric cancer decreased (23.5% to 11.8%). Yet there was no difference according to the WHO classification, Lauren's classification and the location of tumor between the groups. The 5 year survival rates increased 67.7% to 83.7%, according to the group. Multivariative analysis showed that the odd ratios of the early 2000s was 0.715 (95% CI; 0.555~0.921) as compared to that of the 1990s. Conclusion: There were no changes of the clinicopathologic features, like the pattern in western countries, although the incidence early gastric cancer, old age patients and overweight patients increased. The survival rate of early 2000s was better that that of the 1990s.

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A Framework on 3D Object-Based Construction Information Management System for Work Productivity Analysis for Reinforced Concrete Work (철근콘크리트 공사의 작업 생산성 분석을 위한 3차원 객체 활용 정보관리 시스템 구축방안)

  • Kim, Jun;Cha, Heesung
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.2
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    • pp.15-24
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    • 2018
  • Despite the recognition of the need for productivity information and its importance, the feedback of productivity information is not well-established in the construction industry. Effective use of productivity information is required to improve the reliability of construction planning. However, in many cases, on-site productivity information is hardly management effectively, but rather it relies on the experience and/or intuition of project participants. Based on the literature review and expert interviews, the authors recognized that one of the possible solutions is to develop a systematic approach in dealing with productivity information of the construction job-sites. It is required that the new system should not be burdensome to users, purpose-oriented information management, easy-to follow information structure, real-time information feedback, and productivity-related factor recognition. Based on the preliminary investigations, this study proposed a framework for a novel system that facilitate the effective management of construction productivity information. This system has utilized Sketchup software which has good user accessibility by minimizing additional data input and related workload. The proposed system has been designed to input, process, and output the pertinent information through a four-stage process: preparation, input, processing, and output. The inputted construction information is classified into Task Breakdown Structure (TBS) and Material Breakdown Structure (MBS), which are constructed by referring to the contents of the standard specification of building construction, and converted into productivity information. In addition, the converted information is also graphically visualized on the screen, allowing the users to use the productivity information from the job-site. The productivity information management system proposed in this study has been pilot-tested in terms of practical applicability and information availability in the real construction project. Very positive results have been obtained from the usability and the applicability of the system and benefits are expected from the validity test of the system. If the proposed system is used in the planning stage in the construction, the productivity information and the continuous information is accumulated, the expected effectiveness of this study would be conceivably further enhanced.

A Study on the Comparison of the Backfill Loads Obtained by the Marston-Spangler에s Theory and by the Finite Element Analysis for the Metal-Polyethylene Composite Pipes (금속-폴리에틸렌 복합관에 대해서 Marston-Spagler이론과 유한요소해석에 의해 구해진 뒤채움하중의 비교에 관한 연구)

  • 정진호
    • Geotechnical Engineering
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    • v.14 no.5
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    • pp.89-110
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    • 1998
  • Variations of backfill load on the metal-polyethylene composite( MPC ) pipes buried in various trenches backfill afterward were investigated in this paper. The backfill loads obtained by the finite element method( FBM ) were compared with those calculated by the well-known MarstonBpangler(M-5) theory. The reliability of the finite element analysis used in this study was examined by an inaitu best for the buried pipe. The backfill lords and deflections on the real-size pipe buried on-site were measured while increasing the backfill height. In addition, further investigations were made for the variations of the backfill loads as a function of several important parameters such as the backfill soil type, bach. height$(\leq4.0m)$, diameter of the pipe$(B.$1.0m)$, and trench width($\leq 3.0 B_c$). It is confirmed that the M-S theory predicts reasonably well the backfill loafs of the MPC of the M-S backfill coils be 0.13 and 0.15 for the SC and SM coils in the D unman soil model, respectively. The load ratio, Wu-s/WwgM for a narrow trench varies negligibly with the back(111 height but fiends to increase for a wide trench. The ratio increases with increasing diameter of the pipe for a narrow trench while decreasing for a wide trench. It is also found that the ratio generally decreases as the degree of compaction increases and BM soil exhibits larger load ratio than that of SC soil.

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A Study on the Determinants of Investment in Startup Accelerators (스타트업 액셀러레이터의 투자결정요인에 대한 연구)

  • Heo, Joo-yeun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.5
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    • pp.13-35
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    • 2020
  • Startup accelerators are a new type of investors providing a certain amount of shares for imparting education, mentoring, networking, and providing space and seed money that can directly resolve the difficulties faced by nascent entrepreneurs (Clarysse, 2016). Startup accelerators have expanded worldwide as their influence over the startup ecosystem has increasingly been established (Pauwels et al., 2016; Cohen & Hochberg, 2014). This study was conducted to derive investment determinants of startup accelerators that are emerging as major investment players around the world. To this end, the accelerator-type determinants of investment were derived. As previous research on this topic is nonexistent, this process involved qualitative meta-synthesis, literature reviews, observation, and in-depth interviews. First, more than 30 research papers were examined for the determinants of investment for firms at an early stage of their foundation, and the categories and determinants of investment in the relevant studies were comparatively analyzed using qualitative meta-synthesis. Further, related data were investigated to identify the characteristics of accelerators, and the startup evaluation process of US accelerators was studied. The more than 100 questions raised during this process were coded to examine the determinants of investment that accelerators considered important. In-depth interviews were conducted with four US accelerators to identify the characteristics of accelerators and key determinants of investment. Ultimately, 5 categories of accelerator-type determinants of investment and 26 subordinate determinants of investment were derived. The results were verified and supplemented by consulting with seven accelerators in Korea. The results were confirmed after pilot tests and verification by seven domestic accelerators. After confirming the accelerator-type determinants, the reliability of them was verified by examining the importance and priority of each category through the quantitative survey of Korean accelerators. The research that elicited the accelerator-type investment determinants is the first research and is expected to be a major reference to the progress of subsequent studies. This research that systematically derived the investment determinants of the accelerator is expected to make major contributions to the progress of follow-up studies, the process of selecting startups, and the investment decision-making process of the accelerators.

Urban Growth Prediction each Administrative District Considering Social Economic Development Aspect of Climate Change Scenario (기후변화시나리오의 사회경제발전 양상을 고려한 행정구역별 도시성장 예측)

  • Kim, Jin Soo;Park, So Young
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.2
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    • pp.53-62
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    • 2013
  • Land-use/cover changes not only amplify or alleviate influence of climate changes but also they are representative factors to affect environmental change along with climate changes. Thus, the use of land-use/cover changes scenario, consistent climate change scenario is very important to evaluate reliable influences by climate change. The purpose for this study is to predict and analyze the future urban growth considering social and economic scenario from RCP scenario suggested by the 5th evaluation report of IPCC. This study sets land-use/cover changes scenario based on storyline from RCP 4.5 and 8.5 scenario. Urban growth rate for each scenario is calculated by urban area per person and GDP for the last 25 years and regression formula based on double logarithmic model. In addition, the urban demand is predicted by the future population and GDP suggested by the government. This predicted demand is spatially distributed by the urban growth probability map made by logistic regression. As a result, the accuracy of urban growth probability map is appeared to be 89.3~90.3% high and the prediction accuracy for RCP 4.5 showed higher value than that of RCP 8.5. Urban areas from 2020 to 2050 showed consistent growth while the rate of increasing urban areas for RCP 8.5 scenario showed higher value than that of RCP 4.5 scenario. Increase of urban areas is predicted by the fact that famlands are damaged. Especially RCP 8.5 scenario indicated more increase not only farmland but also forest than RCP 4.5 scenario. In addition, the decrease of farmland and forest showed higher level from metropolitan cities than province cities. The results of this study is believed to be used for basic data to clarify complex two-way effects quantitatively for future climate change, land-use/cover changes.