• Journal of Mechanical Science and Technology
• /
• 제20권12호
• /
• pp.2079-2086
• /
• 2006

A fundamental study for developing a fault diagnosis system of a pump is performed by using neural network. Acoustic signals were obtained and converted to frequency domain for normal products and artificially deformed products. The neural network model used in this study was 3-layer type composed of input, hidden, and output layer. The normalized amplitudes at the multiples of real driving frequency were chosen as units of input layer. And the codes of pump malfunctions were selected as units of output layer. Various sets of teach signals made from original data by eliminating some random cases were used in the training. The average errors were approximately proportional to the number of untaught data. Neural network trained by acoustic signals can detect malfunction or diagnose fault of a given machine from the results.

• 대한수학회보
• /
• 제49권4호
• /
• pp.767-774
• /
• 2012

For a positive square-free integer $d$, let $t_d$ and $u_d$ be positive integers such that ${\epsilon}_d=\frac{t_d+u_d{\sqrt{d}}}{\sigma}$ is the fundamental unit of the real quadratic field $\mathbb{Q}(\sqrt{d})$, where ${\sigma}=2$ if $d{\equiv}1$ (mod 4) and ${\sigma}=1$ otherwise For a given positive integer $l$ and a palindromic sequence of positive integers $a_1$, ${\ldots}$, $a_{l-1}$, we define the set $S(l;a_1,{\ldots},a_{l-1})$ := {$d{\in}\mathbb{Z}|d$ > 0, $\sqrt{d}=[a_0,\overline{a_1,{\ldots},2a_0}]$}. We prove that $u_d$ < $d$ for all square-free integer $d{\in}S(l;a_1,{\ldots},a_{l-1})$ with one possible exception and apply it to Ankeny-Artin-Chowla conjecture and Mordell conjecture.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
• /
• pp.81-83
• /
• 2011

A modular house is a house that is assembled on-site from modularized units. As such units are manufactured in a factory, the construction period is reduced, resources are recycled, and quality is improved. However, the construction technique applied to conventional modular houses has not overcome certain structural restrictions, as it is currently used to build houses less than 4 stories in height, which means that it lacks economic feasibility. For this reason, this research aims to develop a scenario of a construction method for Korean modular housing that can be applied to urban-type housing higher than 12 stories. This research is expected to provide fundamental data necessary for the future development of a construction method for Korean modular housing.

• 품질경영학회지
• /
• 제35권3호
• /
• pp.21-36
• /
• 2007

This article is to analyze the service efficiency of public sector using Data Envelopment Analysis(DEA). We tried to measure the public service quality and overall satisfaction by using several DEA models, degree of combination and top2box which is a little bit different methodology from traditional ones. We used CCR, Super-efficiency and Slack based measure(SBM) model in DEA to measure public service efficiency of the 16 public institutions(7 City Halls and 9 Provincial offices). Since the traditional method based on the measurement model(CCR, BCC) has the fundamental problems without taking account of the existence of slacks inputs and outputs in several efficient units, we suggest to measure the exact amount of efficiency and inefficiency of the public sector and rank analysis many efficient units exactly through the slacks-based measure model(SBM)

• 가정과삶의질연구
• /
• 제17권3호
• /
• pp.93-102
• /
• 1999

This paper is to clarify the concepts of "sound home" and "healthy family" Even though "sound home" and "healthy family have different meanings and definitions. many researchers are using them in a mixed ways. Therefore through this paper I tried to make distinction of the meanings of the above concepts as below: 1. Sound Home : Basic and fundamental social units and environment which have strong and healthy family members and performs well not only family function but also have attitudes and willingness to perform family function and maintain their family value and ethics. 2. Healthy Family : Social units which have strong and healthy family members and develop individual personal development -their physical emotional social moral development and self-esteem self-achievemet -and have good interaction enhancement skills- communication decision making stress managing strategies- and also maintain family systems. Whereas "sound home" is more broad concept related to Home Econom cs "healthy family" is more related family relations and interaction.quot; is more related family relations and interaction.

• 한국항만학회지
• /
• 제14권4호
• /
• pp.441-450
• /
• 2000

In order to improve the water quality in semi-enclosed bays, Gug et al. (1997) have proposed a new method to activate the tidal exchange by creation and control of tidal residual current through the addition of artificial elements to creation and control of tidal residual current through the addition of artificial elements to create bottom roughness, so, ot is advisable to arrange as few of these as possible from a point of cost-benefit view. This paper attempts to develop the most suitable shape of artificial bottom roughness units with which to create and control an optimal tidal residual current. Several simple shapes were examined as fundamental cases. Subsequently 38 types of artificial bottom roughness units based on a few simple effective shapes, were examined experimentally. As a result of this research, two types to create artificial roughness.

• International Journal of Advanced Culture Technology
• /
• 제12권1호
• /
• pp.16-19
• /
• 2024

One of the current focal points in the defense sector is how to strategically leverage the technologies of the Fourth Industrial Revolution in military operations. The Fourth Industrial Revolution denotes a transformational shift in the environment where automation and connectivity are maximized, primarily driven by advancements in machine learning and artificial intelligence. Coined by Klaus Schwab at the 2015 Davos Forum, this term signifies a profound change in human activities, akin to how a single machine replaced hundreds of laborers in the past. The military application of Fourth Industrial Revolution technologies is increasingly researched and anticipated to be actively implemented. Combat, as a subset of warfare, entails military actions between units conducting war. Typically performed by units to achieve one or more objectives, the concept of combat involves the fundamental ideas guiding the conduct of military operations against adversaries, both presently and in the future. Hence, it is imperative for our military to develop future combat concepts by harnessing the key technologies of the Fourth Industrial Revolution.

• 전자공학회논문지B
• /
• 제31B권1호
• /
• pp.11-22
• /
• 1994

For the conventional systme based on word, it is very difficult to enlarge the number of vocabulary. To cope with this problem, we must use more fundamental units of speech. For example, syllables and phonemes are such units, Korean speech consists of initial consonants, middle vowels and final consonants and has characteristic that we can obtain syllables from speech easily. In this paper, we show a speech recognition system with the advantage of the syllable characteristics peculiar to the Korean speech. The algorithm of recognition system is the Time Delay Neural Network. To recognize many recognition units, system consists of initial consonants, middle vowels, and final consonants recognition neural network. At first, our system recognizes initial consonants, middle vowels and final consonants. Then using this results, system recognizes isolated words. Through experiments, we got 85.12% recognition rate for 2735 data of initial consonants, 86.95% recognition rate for 3110 data of middle vowels, and 90.58% recognition rate for 1615 data of final consonants. And we got 71.2% recognition rate for 250 data of isolated words.

• 대한기계학회논문집A
• /
• 제26권7호
• /
• pp.1376-1383
• /
• 2002

Seismic qualification of the Air Cleaning Units for nuclear power plant Ulchin 5&6 has been performed with the guideline of ASME Section III and IEEE 344 code. By using the structural and geometrical similarity analysis, the three models to be analyzed are condensed into a single model and, at the same time, the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz, which is the upper frequency limit of the seismic load, response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and electric stability of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As the all combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, the authors confirm the safety of the nuclear equipments Air Cleaning Units studied in this paper.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집B
• /
• pp.404-409
• /
• 2001

Seismic qualification of the Air Cleaning Units for nuclear power plant Ulchin 5&6 has been performed with the guideline of ASME Section III and IEEE 344 code. By using the structural and geometrical similarity analysis, the three models to be analyzed is condensed into a single model and, at the same time, the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz, which is the upper frequency limit of the seismic load, response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and electric stability of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As the all combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, the authors confirm the safety of the nuclear equipments Air Cleaning Units studied in this paper.