• Title/Summary/Keyword: static studies

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A Study on the New Management Technology Model in Service Economy Era (서비스경제시대의 경영기술 연구)

  • Hyunsoo Kim
    • Journal of Service Research and Studies
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    • v.10 no.4
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    • pp.101-125
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    • 2020
  • This study was conducted to derive a management technology model based on the new management framework established in previous studies. The management technology sector, which occupies most of the existing business administration, is defined as a technical division in new management. In this study, the theory of management technology based on the service philosophy of the service economy era was presented. The structure of new business, which is the basis of new management technology, is presented first, the service philosophy of the service economy era where management is performed, and then the management technology model based on service philosophy is presented. The management technology model was derived on the basis of immutable axioms. After presenting new management axioms based on common human ideology and nature and human nature, a management technology model was presented based on axioms. On the basis of the axioms, a new dialectical development model was developed as a model for the dialectical development that maintains a tight balance and a fierce interaction between two opposing parties based on the structure and operation model of service philosophy. In addition to the overall organizational management model, a management function model and a management expansion model were presented. Each detailed technique is presented as a model for dialectical development of opposing confrontations. Management technology is a dynamic technology that is constantly changing, and is an overall technology that takes into account various situations and viewpoints. This study has significance as a basic study to overcome the limitations of the existing static management technology and develop dynamic management technology. Future research requires empirical analytical studies on new management technology models.

AI Security Plan for Public Safety Network App Store (재난안전통신망 앱스토어를 위한 AI 보안 방안 마련)

  • Jung, Jae-eun;Ahn, Jung-hyun;Baik, Nam-kyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.458-460
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    • 2021
  • The provision and application of public safety network in Korea is still insufficient for security response to the mobile app of public safety network in the stages of development, initial construction, demonstration, and initial service. The available terminals on the Disaster Safety Network (PS-LTE) are open, Android-based, dedicated terminals that potentially have vulnerabilities that can be used for a variety of mobile malware, requiring preemptive responses similar to FirstNet Certified in U.S and Google's Google Play Protect. In this paper, before listing the application service app on the public safety network mobile app store, we construct a data set for malicious and normal apps, extract features, select the most effective AI model, perform static and dynamic analysis, and analyze Based on the result, if it is not a malicious app, it is suggested to list it in the App Store. As it becomes essential to provide a service that blocks malicious behavior app listing in advance, it is essential to provide authorized authentication to minimize the security blind spot of the public safety network, and to provide certified apps for disaster safety and application service support. The safety of the public safety network can be secured.

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Studies on Determinant Factors of SCM Performance: From the Supplier Perspective (SCM 성과 결정요인에 관한 통합적 연구: 공급업체 관점으로)

  • Park, Kwang-Oh;Chang, Hwal-Sik
    • Asia pacific journal of information systems
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    • v.21 no.1
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    • pp.1-27
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    • 2011
  • In an attempt to cope with widespread, dynamic, and accelerating changes in both internal and external business environments, companies often utilize information technologies such as SCM(Supply Chain Management). To date, SCM research has mainly focused on the effects of dynamic factors on SCM success and emphasized adoption strategies and critical success factors. Consequently, the effects of more static factors such as interdependency between SCM partners have been largely ignored. The purpose of this study, therefore, is to examine the effects of both dynamic and static factors on SCM performance by controlling for information quality and partnership quality. The five factors examined in this study include innovative ness, mutual dependency, quality of information, partnership quality, and SCM performance. All factors were examined from the perspective of part suppliers, except the mutual dependency which was examined from two aspects: supplier's dependency on customer and customer's dependency on supplier. Data was collected through five hundred survey questionnaires distributed to the part supplier companies that have implemented SCM systems for at least one year. As a result, a total of 170 valid responses were obtained. A structural equation research model was fitted using SAS 9.1.3 and SMART-PLS 2.0. The results of this study can be summarized as follows. First, innovativeness positively affected SCM information quality. SCM partnership quality, and ultimately SCM performance. The path coefficient between innovativeness and information quality was 0.387, with a t-value of 3.528. Innovativeness also had a positively direct effect on partnership quality. The path coefficient was 0.351 with a t-value of 3.366. The total effect of innovativeness on partnership quality was significant, although its indirect effect on partnership quality by altering information quality was negligible. The total indirect effect of innovativeness on SCM performance by affecting information quality and partnership quality was significant with a p-value of 0.014. Innovativeness played an important role in determining SCM performance. Second, mutual dependency showed no significant effect on SCM information quality. This result contradicts the earlier assertion that the more dependent two companies are, the more accurate and timely the information they exchange ought to be. This study showed that this may not be the case; a partner may provide information of poor quality even when it is strongly dependent on the other. Mutual dependency showed significant effect on partnership quality. However, when the mutual dependency perceived by suppliers was divided into two parts, one being a supplier's dependency on its customer company and the other being a customer's dependency on the supplier, the latter showed a significant impact on the perceived SCM partnership quality. This result indicates that a customer company can hardly improve the partnership quality perceived by suppliers by making them more dependent. It improves only when the suppliers perceive that their partners, typically having more bargaining power, are more dependent on them. The overall effect of mutual dependency of any kind on SCM performance, however, was not significant. Although mutual dependency has been mentioned as an important static factor influencing almost every aspect of cooperation on a supply chain, its influences may not be as significant as it was initially perceived to be. Third, the correlation between information quality and partnership quality was 0.448 with a p-value of less than 0.001. Information quality had a path coefficient of 0.256 to partnership quality with a t-value of 2.940. The quality of information exchanged between partners may have an impact on their partnership quality. Fourth, information quality also had a significant impact on SCM performance with a path coefficient of 0.325 with a t-value of 3.611. In this study, SCM performance was divided into four categories: product quality, cost saving, service quality, and order fulfillment. Information quality has Significant impacts on product quality, cost saving and service quality, but not on order fulfillment. Fifth, partnership quality, as expected, had a significant impact on SCM performance. The path coefficient was 0.403 with a t-value of 3.539. Partnership quality, like information quality, had positive impacts on product quality, cost saving and service quality, but showed no impact on order fulfillment. It seemed that order fulfillment is the hardest category of performance that SCM can satisfy. One major limitation of this study is that it surveyed only the suppliers. To better understand the dual aspects of SCM, it is important to survey both suppliers and the assemblers, especially in pairs. This research, to our best knowledge, was the first attempt to study the level of dependency between the two groups by measuring the dual aspects of SCM and studying mutual dependency from the categories of suppliers and assemblers each.. In the future, a more comprehensive and precise measurement of SCM characteristics needs to be achieved by examining from both the supplier's and assembler's perspectives.

Studies on Reaction Parameters for Composting of Paper Mill Sludge in a Small-Scale Reactor and Static Piles (제지슬럿지의 퇴비화를 위한 반응변수 연구)

  • Han, Shin Ho;Chung, Young Ryun;Cho, Cheon Hee;Kang, Moon Hee;Oh, Say Kyun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.2 no.2
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    • pp.19-29
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    • 1994
  • A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

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Quality Characteristics of Brown Rice Vinegar by Ferment Ratio (발효제 비율에 따른 현미식초의 품질특성)

  • Baek, Chang-Ho;Choi, Ji-Ho;Choi, Han-Seok;Jeong, Seok-Tae;Lee, Su-Won;Kwon, Joong-Ho;Woo, Seung-Mi;Jeong, Yong-Jin;Yeo, Soo-Hwan
    • Food Science and Preservation
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    • v.18 no.6
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    • pp.875-883
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    • 2011
  • Brown rice vinegar was made from brown rice mash with different brewing starter addition rates in static culture, and its quality characteristics were investigated. As a result, the amounts of alcohol produced in the fermentation process were shown to be 9.1, 8.8, 8.6 and 8.5% in the Nuruk 75 : crude enzyme 25 (B), Nuruk 50 : crude enzyme 50 (C), Nuruk 25 : crude enzyme 75 (D) and Nuruk 0 : crude enzyme 100 (E), respectively. The higher the percentage of crude enzyme added was, the lower the alcohol content that was produced. Nuruk 100 : crude enzyme 0 (A) was appeared to contain the lowest alcohol content (7.7%). In addition, the titratable acidity in all the groups was about 0.7%. The final titratable acidity (BV) of brown rice vinegar made with static culture was the highest (approximately 5.2%). The initial pH appeared to be between 3.6~4.0 and steadily decreased as the fermentation progressed, and the pH was almost unchanged after 15 day fermentation. The examination of the changes in the organic acids showed that the acetic acid content was similar in all the groups, and that the single starter added (AV, EV) group had much more other organic acids than the mixed starters added (BV, CV, DV) group. From these results, the mixed starters (Nuruk and crude enzyme) added group appeared to be superior to the single starter added in terms of alcohol production ability and vinegar quality. As the future aging process, however, is expected to change the flavor components and sensory characteristics, studies on various quality factors of vinegar are needed.

Mobilities and Phenomenology of Place, A Perspective for the Popular Narrative Studies -David Seamon's Life Takes Place (모빌리티와 장소 현상학, 대중서사 연구의 한 관점 -데이비드 시먼의 『삶은 장소에서 일어난다』를 중심으로)

  • Kim, Tae-Hee
    • Journal of Popular Narrative
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    • v.25 no.4
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    • pp.469-506
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    • 2019
  • More than a few existing studies on popular narratives that pay attention to 'place' tend to adopt as their theoretical framework the celebrated distinction between space and place. According to this distinction, to put it simply, space is allegedly mobile, whereas place is static. Given this distinction, and in this age of high-mobility, where the spaces of mobilities seem to rapidly and extensively undermine the places of immobilities, would studies on popular narratives focusing on 'place' still remain convincing? Referring to David Seamon's recent book Life Takes Place: Phenomenology, Lifeworlds, and Place Making, this article aims to consider the possibility of studies on popular narratives in the era of high-mobility. To explore the concept of 'place' through phenomenological methodology, Seamon's book uses a theoretical framework called the 'progressive approximation,' which is attentive to synergistic relationality. According to this approach, the place should first be put under scrutiny as a whole, i.e. as the monad of place. Phenomenological studies on the monad of place as a whole identify places as the fundamental condition for human beings. Then, in accordance with the 'progressive' order of research, places are studied as dyads, i.e. as binary oppositions. Through these analyses, movement/rest, insideness/outsideness, the ordinary/the extra-ordinary, the within/the without, homeworld/alienworld are identified as the five dyads of place. To make a detour around these binary oppositions and confrontations, however, phenomenological studies on place now advance to the higher order of six place triads including place interaction, place identity, place release, place realization, place intensification, and place creation, whereby the study of place progressively approaches the 'approximate' essence of place. Reflectively asking himself about the idea of 'place' in the high-mobility era, the author of this informative and insightful book submits an answer that place is still the fundamental sine qua non of human beings. However, this answer is more likely to be bounded by the binary opposition of space/place, and movement/rest accordingly. In this article, I suggest as an alternative and hopefully more promising answer a perspective of transcending this kind of a dead-end dichotomy and of performing 'place-making' through the mobilities themselves, while presenting a noticeable example of the manner in which research on popular narratives could begin from this perspective.

Pulmonary Function Following Open Heart Surgery -early and late postoperative changes- (개심술후 폐기능 -수술직후 및 장기간의 추이에 대하여-)

  • 이성행
    • Journal of Chest Surgery
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    • v.13 no.4
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    • pp.364-374
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    • 1980
  • Twenty-two patients were selected for evaluation of pre-and postoperative pulmonary function. These patients were performed open cardiac surgery with the extracorporeal circulation from March 1979 to July 1980 at the Department of Thoracic and Cardiovascular Surgery, Kyungbook National University Hospital. Patients were classified with ventricular septal defect 5 cases, atrial septal defect 5 cases, tetralogy of Fallot 5 cases, mitral stenosis 4 cases, rupture of aneurysm of sinus Valsalva 1 case, left atrial myxoma I case, and aortic insufficiency 1 case. The pulmonary function tests were performed and listed: [1] respiratory rate, tidal volume [TV], and minute volume[MV], [2] forced vital capacity [FVC] and forced expiratory volume[FEV 0.5 & FEV 1.0], [3] forced expiratory flow [FEF 200-1200 ml & FEF 25-75%]. [4] Maximal voluntary ventilation [MVV], [5] residual volume [RV] and functional residual capacity[FRC], measured by a helium dilution technique. Respiratory rate increased during the early postoperative days and tidal volume decreased significantly. These values returned to the preoperative levels after postoperative 5-6 days. Minute volume decreased slightly, but essentially unchanged. Preoperative mean values of the forced vital capacity, functional residual capacity and total lung capacity decreased [63.2%, 87.2% & 77.3% predicted, respectively], and early postoperatively these values decreased further [19.6%, 76.0% & 38.0% predicted], but later progressively increased to the preoperative levels. In residual volume, there was no decline in the preoperative mean values [100.9% predicted] and postoperatively the value rather increased [106.3-161.7% predicted]. Forced expiratory volume [FEV 0.5 & FEV 1.0] and forced expiratory flow [FEF 200-1200 ml & FEF 25-75%] also revealed significant declines in the early postoperative period. There was no significant difference in values of the spirometric pulmonary function tests, such as FEF 1.O and FEF 25-75% between successful weaning group [17 cases] extubated within 24 hrs post-operatively and unsuccessful weaning group [5 cases] extubated beyond 24 hrs. Static compliance and airway resistance measured for the two cases during assisted ventilation, however, any information was not obtained. Long term follow-up pulmonary function studies were carried out for 8 cases in 9 months post-operatively. All of the results returned to the pre-operative or to normal predicted levels except FVC, FEV 1.0, and FEF 25-75% those showed minimal declines compared to the pre-operative figures.

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The effects of increased unilateral and bilateral calcaneal eversion on pelvic and trunk alignment in standing position

  • Yi, Jaehoon
    • Physical Therapy Rehabilitation Science
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    • v.5 no.2
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    • pp.84-88
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    • 2016
  • Objective: Generally, it is known that there is a correlation between excessive calcaneus eversion and a patient with low back pain and it also affects pelvic alignment. However, there are not enough studies that show calcaneal eversion having an effect on the alignment of the trunk. Design: Cross-sectional study. Methods: A 3-dimensional motion analysis system was used to assess the lower limbs, pelvic alignment, and trunk alignment with increased unilateral and bilateral calcaneal eversion in twenty-one subjects. All subjects were asked to maintain a static posture for seven seconds on a wedge three times per posture for measurement and analysis purposes. The wedge used in the process was a lateral wedge with a 10-degree tilt to the lateral direction. To unify all of the subjects' foot position, the front and inner side of the wedge were marked. The height of the tilted wedge's inner side and flat wedge were balanced equally in order to be able to maintain the lateral part of the foot to the same height when producing an increased calcaneal eversion. Results: Comparing the changes in trunk and pelvic alignment in accordance to calcaneal eversion for each posture, there was a significant different in the X and Y-axis for each posture, but not in the Z-axis (p<0.05). Thus, it can be confirmed that calcaneal eversion in the sagittal plane and frontal plane may have and effect on the pelvis and the trunk. Conclusions: Postures with increased bilateral and unilateral calcaneal eversion has an effect on pelvic alignment, but does not cause any changes in trunk alignment.

Design of the Hydro-Mechanical Transmission for a 55kW-Class Agricultural Tractor (55kW급 농업용 트랙터 정유압 기계식 변속기 설계)

  • Baek, Seung Min;Kim, Wan Soo;Kim, Yeon Soo;Baek, Seung Yun;Kim, Yong Joo
    • Journal of Drive and Control
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    • v.17 no.2
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    • pp.19-27
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    • 2020
  • The purpose of this study was to suggest design criteria for the HMT (hydro-mechanical transmission) of a 55 kW-class agricultural tractor, develop a simulation model, and evaluate its performance such as axle rotational speed, tractor speed, and power transmission efficiency. In this study, the HMT comprised a compound planetary gear and a HSU (hydro-static unit), and the compound planetary gear comprised two planetary gear sets. The HMT has three gear stages, and the maximum tractor speed was selected as 40 km/h. The simulation time was set at 2736 hours considering the lifetime of the tractor, and the simulation was performed for each gear stage at the engine-rated power conditions. As a result of the simulation, the axle rotational speeds for each gear stage were 39, 77, and 158 rpm, respectively. The range of tractor speed for each gear stage were 1.05-10.22 km/h, 10.74-20.17 km/h, and 20.70-41.40 km/h, respectively. The APE (absolute percentage gear) for the tractor's maximum speed between target value and simulation results were 2.20%, 0.85%, and 3.50%, respectively. Also, the power transmission efficiency for each gear stage were 0-75%, 72-81%, and 69-81%, respectively. The simulation results for the power transmission efficiency of the HMT were similar with the results of the previous research. This was a basic study on the development of the HMT for an agricultural tractor. In future studies, it is necessary to develop a tractor platform and evaluate the performance. The comparison between the simulation model and the HMT tractor should be performed.

On the Numerical Stability of Dynamic Reliability Analysis Method (동적 신뢰성 해석 기법의 수치 안정성에 관하여)

  • Lee, Do-Geun;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.35 no.3
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    • pp.49-57
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    • 2020
  • In comparison with the existing static reliability analysis methods, the dynamic reliability analysis(DyRA) method is more suitable for estimating the failure probability of a structure subjected to earthquake excitations because it can take into account the frequency characteristics and damping capacity of the structure. However, the DyRA is known to have an issue of numerical stability due to the uncertainty in random sampling of the earthquake excitations. In order to solve this numerical stability issue in the DyRA approach, this study proposed two earthquake-scale factors. The first factor is defined as the ratio of the first earthquake excitation over the maximum value of the remaining excitations, and the second factor is defined as the condition number of the matrix consisting of the earthquake excitations. Then, we have performed parametric studies of two factors on numerical stability of the DyRA method. In illustrative example, it was clearly confirmed that the two factors can be used to verify the numerical stability of the proposed DyRA method. However, there exists a difference between the two factors. The first factor showed some overlapping region between the stable results and the unstable results so that it requires some additional reliability analysis to guarantee the stability of the DyRA method. On the contrary, the second factor clearly distinguished the stable and unstable results of the DyRA method without any overlapping region. Therefore, the second factor can be said to be better than the first factor as the criterion to determine whether or not the proposed DyRA method guarantees its numerical stability. In addition, the accuracy of the numerical analysis results of the proposed DyRA has been verified in comparison with those of the existing first-order reliability method(FORM), Monte Carlo simulation(MCS) method and subset simulation method(SSM). The comparative results confirmed that the proposed DyRA method can provide accurate and reliable estimation of the structural failure probability while maintaining the superior numerical efficiency over the existing methods.