• Steel and Composite Structures
• /
• 제51권4호
• /
• pp.417-440
• /
• 2024

Artificial neural networks (ANN) have been the focus of several studies when it comes to evaluating the pile's bearing capacity. Nonetheless, the principal drawbacks of employing this method are the sluggish rate of convergence and the constraints of ANN in locating global minima. The current work aimed to build four ANN-based prediction models enhanced with methods from the black hole algorithm (BHA), league championship algorithm (LCA), shuffled complex evolution (SCE), and symbiotic organisms search (SOS) to estimate the carrying capacity of piles in cold climates. To provide the crucial dataset required to build the model, fifty-eight concrete pile experiments were conducted. The pile geometrical properties, internal friction angle 𝛗 shaft, internal friction angle 𝛗 tip, pile length, pile area, and vertical effective stress were established as the network inputs, and the BHA, LCA, SCE, and SOS-based ANN models were set up to provide the pile bearing capacity as the output. Following a sensitivity analysis to determine the optimal BHA, LCA, SCE, and SOS parameters and a train and test procedure to determine the optimal network architecture or the number of hidden nodes, the best prediction approach was selected. The outcomes show a good agreement between the measured bearing capabilities and the pile bearing capacities forecasted by SCE-MLP. The testing dataset's respective mean square error and coefficient of determination, which are 0.91846 and 391.1539, indicate that using the SCE-MLP approach as a practical, efficient, and highly reliable technique to forecast the pile's bearing capacity is advantageous.

• 한국전자거래학회지
• /
• 제21권3호
• /
• pp.129-151
• /
• 2016

본 연구는 PMO(Project Management Office)가 도입된 IT 프로젝트 경험자를 대상으로, 내 외부 PMO의 역량과 프로젝트 성과 간의 관계에 있어 조직공정성을 매개변수로 하여 영향 관계를 파악한 연구이다. 연구결과, 내부 PMO 역량은 절차공정성과 분배공정성뿐만 아니라 프로젝트 성과와도 직접적 관련이 있는 것으로 나타났다. 반면 외부 PMO 역량은 절차공정성에만 관련이 있고, 프로젝트 성과와는 관련이 없는 것으로 분석되었다. 또한 절차공정성과 분배공정성은 모두 프로젝트 성과와 관련이 있는 것으로 확인됐다. 일반적으로 조직 내부에서는 프로젝트 관리역량을 충분히 갖추고 있음에도 불구하고, 프로젝트 관리의 공정성 객관성을 위해 외부 전문 컨설팅 기관의 역량을 도입한다. 그러나 절차공정성에 대한 검정통계량값의 경우, 내부 PMO 역량이 외부 PMO 역량에 비해 상대적으로 높고 유의성이 있는 것으로 드러났다. 또한 내부 PMO 역량만이 분배공정성과 프로젝트 성과에 직접적 상관성을 가지는 것으로 나타났다. 본 연구는 내 외부 PMO 활동 수행에 필요한 인적 역량을 도출하는데 그 지표가 될 것이며, 내 외부 PMO 도입을 통한 프로젝트 관리 전략을 세우는데 기반을 마련했다는데 의의가 있다.

• 대한기계학회논문집B
• /
• 제22권1호
• /
• pp.70-78
• /
• 1998

The present study has tested semi-empirical loss models for a reliable performance prediction of mixed-flow pumps with four different specific speeds. In order to improve the predictive capabilities, this paper recommends a new internal loss model and a modified parasitic loss model. The prediction method presented here is also compared with that based on two-dimensional cascade theory. Predicted performance curves by the proposed set of loss models agree fairly well with experimental data for a variety of mixed-flow pumps in the normal operating range, but further studies considering 'droop-like' head performance characteristic due to flow reversal in mixed-flow impellers at low flow range near shut-off head are needed.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 B
• /
• pp.1012-1015
• /
• 1992

A gate-turn-off thyristor (GTO) that has a fuction of self-commutation is a device that can be turned on like a thyristor with a single pulse of gate current and turned-off by injecting a negative gate current pulse. GTOs have been in existence almost from the beginning of thyristor era, recently are these devices being developed with large power-handling capabilities and improved performance, and they are gaining popularity In conversion equipment. In this paper, the effects of internal parameters of GTO model using a circuit containing two transistors and three resistors the switching operation and the turn-off snubber characteristics is investigated using SPICE program.

• 한국항공운항학회:학술대회논문집
• /
• 한국항공운항학회 2016년도 춘계학술대회
• /
• pp.9-13
• /
• 2016

Reaction drive rotor system is capable of providing hover and low speed capabilities to different aircraft concepts such as stopped rotor wing, canard rotor wing, compound gyroplane etc. Existing sizing and analysis tools for shaft drive rotor system cannot be applied directly to this system. The available methodologies to size this system were reviewed. Power available calculation procedure and factors affects it were addressed prior to sizing process. Various design issues of this system due to interrelationship of internal gas flow dynamics and rotor external aerodynamics was discussed. Finally, a modification that is required in existing sizing methodologies was identified and combined approach in sizing process to consider the interrelationship among engine, rotor and blade duct was introduced.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 춘계학술대회 논문집 전기설비전문위원
• /
• pp.123-124
• /
• 2008

Battery is one of the emergency power. Battery reliability is a very important to keep up the minimum of building capabilities in case of interruption of electric power. Instantaneous discharge test is carried out for measuring transient voltage change(${\Delta}V$) and internal instantaneous impedance(Z), and then it is compared with discharge test results for the estimating the battery capacity. As a result, it was confirmed that the voltage change(${\Delta}V$) and the instantaneous impedance of the batteries failed in actual discharge test were higher that those of the sound batteries. Such an instantaneous discharge test can be a diagnosis of battery sound.

• 경영과학
• /
• 제12권1호
• /
• pp.79-94
• /
• 1995

Nowadays, a large number of Executive Information Systems (EIS) have been developed around the world, most of them are in the United States. These systems were mainly for senior executives to monitor the current status and to find out possible opportunities/problems of their organizations. They also provide a number of capabilities such as drill-down, exception reporting, and trend analysis on hard and soft data from both internal and external sources. The purpose of this study is to see where the current status of the use of EIS in Korea and the Korean EIS industry are. The survey result is valuable to Korean EIS developers - both in-house developers and outside vendors. They can develop appropriate EISs based on the findings.

• 산경연구논집
• /
• 제3권1호
• /
• pp.17-24
• /
• 2012

The logistics industry is based on personnel, and without talented individuals, corporate success in impossible. Therefore, we should fully understand and research China's future in logistics along with the status of related personnel in the country, and seek to establish valid measures concerning our country's logistics personnel. In order for Korea's logistics industry to develop, we should also consider professional training of personnel and the establishment of training facilities. The training of logistics personnel can promote national competitiveness, and can contributetowards the national economy. Also, the production of competitive personnel can secure the healthy and secure development of the Chinese logistics industry. In conclusion, our companies should continue professional training for current and new employees, and through internal training and certifications, improve workers' capabilities and productivity, promoting the healthy development of the logistics industry.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
• /
• pp.950-953
• /
• 2006

SIMP is an international project funded by INTAS aimed at improving the information content, which can be inferred from multi-sensor satellite imagery of marine coastal areas. Scientific teams from Germany, UK, Portugal, and Russia focus on the development of novel tools for marine remote sensing of the coastal zone. In particular, the project teams' benefit from the fact that surface films may enhance the signatures of hydrodynamic processes such as plumes, internal waves, eddies, etc., on microwave, optical, and infrared imagery. The project's objectives are to develop a robust methodology for identifying slick-related phenomena/processes through their surface signatures and thereby, to improve the discrimination capabilities between slicks and other oceanic and atmospheric phenomena by taking into account information gained from satellite imagery quasi-simultaneously recorded at microwave, visible and IR wavelengths. The results of the two project years are summarized. Examples are given for the project’s web presentation, laboratory and field experiments, and of the analyses of various satellite data.

• 통상정보연구
• /
• 제9권4호
• /
• pp.3-19
• /
• 2007

The purpose of this paper is to study the pattern of interactive learning in strategic networks. Interactive learning is defined as the exchange and sharing of knowledge resources conducive to innovation between an innovator firm, its suppliers, and/or its customers. The strength of internal knowledge resources can either hamper or facilitate levels of interactive learning. We assume that more complex innovative activities urge firms to co-ordinate and exchange information between users and producers, which implies a higher level of interactive learning. To test our theoretical claims, we estimated the level of interactive learning of firms in strategic networks with: (1) their customers, (2) their suppliers. Theses analyses allow a comparison of the antecedents of interactive learning of firms participating in strategic networks. Our findings suggest that interactive learning with customers is positively affected by company's capabilities and value-created activities, and with supplies is positively affected by value-created activities and technology innovation centers.