• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.319-323
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• 2002

Recently, new polishing system which was made by magnetic intelligent compound (MAGIC) was invented and, the study is going on for practical use the analysis of factors, that is, the kind of polishing grain, composition ratio of wheel elements, machining frequency, polishing pressure, which the main influence for polishing efficiency are the first step. In this study, analyzed influence of wheel raw material composition ratio on surface roughness.

• 국제지역연구
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• 제20권2호
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• pp.3-23
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• 2016

본 연구는 미국의 비전통적 통화정책인 양적완화가 수출 위주의 성장전략을 채택하고 있는 한국, 일본, 중국 등 아시아 3국의 실물경제와 금융시장에 미치는 영향을 경제이론에 근거한 SVAR모형을 통해 실증분석 하였다. 추정결과 한국과 일본, 중국의 대(對) 달러 실질실효환율 상승 충격이 실물경제인 경상수지와 산업생산지수에 부정적인 영향을 미치는 것으로 나타났다. 이는 한국과 일본, 중국의 자국통화 강세가 수출품의 가격경쟁력을 하락시켜 실물경제에 부정적인 영향을 미칠 수 있음을 확인하는 결과라 할 수 있다. 다음으로 대(對) 달러 실질실효환율 상승 충격은 한국과 일본의 국채 금리를 하락시킨 반면 중국의 국채 금리는 상승시키는 것으로 나타났다. 이는 한국과 일본의 경우 대외개방도가 높은 선진화된 금융시장을 통해 환차익을 고려한 외국인 투자 자금을 유입시킴에 따라 국채 금리가 하락하는 경로를 따르는 반면 중국의 금융시장은 대외개방에 대한 규제가 아직 강력한 만큼 대외적인 영향보다는 대내적인 정책에 더 큰 영향을 받기 때문인 것으로 생각된다. 마지막으로 한국은 환율 충격에 대한 각 변수 반응이 일본과 중국에 비해 크게 나타났으며 이는 경제규모 및 통화에 대한 국제적 지위 등을 고려할 때, 한국이 두 국가에 비해 외부 충격에 상대적으로 취약함을 나타내는 결과로 보여진다.

• 보건교육건강증진학회지
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• 제8권2호
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• pp.34-51
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• 1991

In the research and analysis for survey practice on stability on the nutrition intake relities to an affect influence factor for variable reason to discovers dweller in cities area which is in order to prevent an unfortunately influence that thus obviously restricted by nutrition intake would be restoration. And then attempted to avhivement of stability fulfil to correct nutrition intake needed under the establish for effectiveness measured to provide the primary required resources be considerations must accomplish certain survey of goals. Therefore subject of criticism for survey was conducted during January 4 1990 to January 24 1990 through 20 days adapted place were Seoul, Taegu and Pohang cities dweller 1206 person be conducted under the expert survey personnel by directly the survey was conducted with the questional form has atapted for its survey conclusion of result be summarixed as bellow. 1) The subject of criticism for survey was ferformed to personnel adapted age group 40 to 49 were 24.9%, Age group 50 to 59 were 18.4% shows most adult group has significant higher value rate appearenced. In consideration the education level were evaluated the college grauated ; 48.8% and High School graduated: 30.1% shows that more educated level has significant higher rate value were appearenced. 2) On the subject of criticism to evaluation for adapted personnel by native place such as larger citypeople ; 29.6%, Farming and fishing village people were 28.4%, although the classfication of job analysis for estimation appearence rate were ; students 27.4%, Sales and service field personnel rate ; 15.1% and expert technique field personnel were ; 90% comprehensively appearenced. Although consideration for ecnomics situation review to the middle level shows of rate ; 61.7% and lower level was appearenced rate ; 23.9% of each others. 3) The people of resident in cities were appearenced nutrition intake has more than 2 weeks continuousely practiced by experiance rate shows ; 72% thus intake has experianced rate were 74.6% and female was 68.5% affact is comprehensively male has more many higher rate valued. In the classfication by age group 60 year old has 100% they have experiaced of nutrition intake and age group 50 to be appearenced its rate ; 76.4 % and age group 40 were 75.5% Thus result of survey for comparative rate shows in generally say more aged group has intake significant higher than younger age of group. Nevertheless, age group 10 years old be experienced of nutrition of intake rate ; 63.2% and age group 20 shows 73.9% was comparative more significant higher than age group 30 years old level adolescents.

• 한국통신학회논문지
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• 제16권12호
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• pp.1366-1381
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• 1991

톤간섭과 잡음 환경하에서 m-분포 페이딩 채널을 통해 수신되는 DS/QPSK 신호의 오율식을 유도한 후 이를 수치계산하여 그림으로 나타내어 검토했다. 오율식의 유도는 두 가지 경우에 대하여 행했다. 즉, 하나는 신호만 페이딩의 영향을 받는 경우이고 다른 하나는 신호와 간섭이 동시에 페이딩의 영향을 받는 경우이다. 수치 계산하여 얻어진 결과로부터 신호만 페이딩의 영향을 받는 경우보다 신호와 간섭이 동시에 페이딩의 영향을 받는 경웨 오율특성이 더 열화되는데 직접확산을 이용하면 큰 오율개선이 이루어진다는 것을 알수 있었다. 그러나 그 오율의 개선폭은 간섭과 페이딩의 영향이 약해지면 약해질수록 작아진다는 것을 확인할수 있었다.

• Architectural research
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• 제24권1호
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• pp.1-11
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• 2022

As the occurrence of a crime is dependent on different factors, their correlations are beyond the ordinary cognitive range. Owing to this limitation, systems face difficulty in correlating various factors, thereby requiring the assistance of artificial intelligence (AI) to overcome such limitations. Therefore, AI has become indispensable for crime prediction. Crimes can cause severe and irrevocable damage to a society. Recently, big data has been introduced for developing highly accurate models for crime prediction. Prediction of night crimes should be given significant consideration, because crimes primarily occur during nights, when the spatiotemporal characteristics become vulnerable to crimes. Many environmental factors that influence crime rate are applied for crime prediction, and their influence on crime rate may differ based on temporal characteristics and the nature of crime. This study aims to identify the environmental factors that influence sex and theft crimes occurring at night and proposes an artificial neural network (ANN) model to predict sex and theft crimes at night in random areas. The crime data of A district in Seoul for 12 years (2004-2015) was used, and environmental factors that influence sex and theft crimes were derived through multiple regression analysis. Two types of crime prediction models were developed: Type A using all environmental factors as input data; Type B with only the significant factors (obtained from regression analysis) as input data. The Type B model exhibited a greater accuracy than Type A, by 3.26 and 9.47 % higher for theft and sex crimes, respectively.

• Geomechanics and Engineering
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• 제35권4호
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• pp.385-393
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• 2023

To analyze the consolidation with horizontal sand drains, the plane strain consolidation model under multi-ramp loading is established, and its corresponding analytical solution is derived by using the separation of variables method. The proposed solution is verified by the field measurement data and finite element results. Then, the effects of the loading mode and stress distribution on consolidation and dissipation of pore pressure are investigated. At the same time, the influence of hydraulic conductivity and thickness of sand blankets on soil consolidation are also analyzed. The results show that the loading mode has a significant effect on both the soil consolidation rate and generation-dissipation process of pore water pressure. In contrast, the influence of stress distribution on pore pressure dissipation is obvious, while its influence on soil consolidation rate is negligible. To guarantee the fully drained condition of the sand blanket, the ratio of hydraulic conductivity of the sand blanket to that of clay layer k_d/k_v should range from 1.0×10⁴ to 1.0×10⁶ with soil width varying from 100 m to 1000 m. A larger soil width correspondingly needs a greater value of kd/kv to make sure that the pore water can flow through the sand blanket smoothly with little resistance. When the soil width is relatively small (e.g., less than 100 m), the effect of thickness of the sand blanket on soil consolidation is insignificant. And its influence appears obvious gradually with the increase of the soil width.

• 한국패류학회지
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• 제25권1호
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• pp.15-22
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• 2009

Because it is known that bivalve hearts contain various modulatory systems activated by neuroendocrine substances, it was examined whether different classes of endogenous and synthetic drugs of neuroendocrinological importance can influence cardiac functions of the Pacific oyster Crassostrea gigas. Cholinergically active agents acetylcholine and carbachol increased heart rates while diminishing cardiac contractility. Adrenergically active substances norepinephrine (NE) and epinephrine (Epi) also induced heart rate increase and contractility decrease. An $\alpha_1$-adrenergic receptor-selective agonist phenyephrine (PE) failed to modulate either parameter. The Epi-induced heart rate increase and contractile depression were both blocked significantly by non-selective $\beta_1/\beta_2$-adrenergic antagonist propranolol. A $\beta_1$-selective antagonist atenolol prevented Epi-induced heart rate decrease but not the contractile depression, suggesting possible $\beta_2$ receptors for Epi-induced contractile depression. The three autacoids examined exerted discrete responses: histamine increased heart rate and depressed contraction; $\gamma$-amino-butyric acid increased both parameters; serotonin failed to change either parameter. The 5 piscine anesthetic agents examined, MS-222, benzocaine, quinaldine, urethane, pantocaine and pentobarbital, all failed to influence the cardiac function of oysters. Collectively, activities of neuroendocrinologically acting agents in mammals showed unexpected and distinct activities from those in mammalian cardiovascular systems. These results obtained from substances of different physiological functions can serve as a basis for understanding neuroendocrine control of the heart function in Pacific oyster.

• 한국지반공학회논문집
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• 제20권8호
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• pp.89-96
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• 2004

흐르는 물의 침식유발능력과 지반의 침식저항능력을 동시에 고려할 수 있는 새로운 교량세굴해석 모델을 개발하기 위한 많은 연구가 진행되었으며, 이러한 노력의 일환으로 지반의 침식율을 정량화할 수 있는 세굴률 시험기가 개발되었다. 본 연구에서는 세굴률 시험기를 이용하여 3종의 재성형 점토에 대해 세굴률 실험을 실시하였다. 재성형 점토의 세굴률 실험을 통해 성형하중의 변화에 따른 세립토의 침식특성을 분석하였으며, 또한 토성치와 침식율의 상관관계 분석을 시도하였다. 실험과 해석을 통해, 토질정수 중 특히 단위중량과 전단강도는 지반의 침식특성에 큰 영향을 미치는 것으로 나타났다.

• 한국연소학회지
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• 제5권1호
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• pp.7-18
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• 2000

Numerical simulations of counterflow non-premixed $CH_4/C_2HCl_3/Air$ flames added 8%(by volume) C2HCl3 on the fuel side are conducted at atmospheric pressure using a detailed chemical reaction mechanism in order to understand the effect of strain rates. A detailed sensitivity analysis is also performed in order to assess the relative influence of each reaction on the flame established at a strain rate of 200s-1. The structure of flames (i.e., temperature, velocity, and concentration of species) established at both a strain rate of 150s-1 and 300s-1 are investigated. As the strain rate increases, the "flame zone" is restricted to a narrower range and the position of maximum temperature is shifted to the fuel side. The concentrations of major species, H2O, CO, H2, HCl, Cl2, and Cl are decreased with increased strain rate. The reaction involving chlorine, CH4 + Cl $\rightarrow$ CH3 + HCl, instead of the reaction, CH4 + H $\rightarrow$ CH3 + H2 influences the consumption of methane. C2HCl3 + OH $\rightarrow$ CHCl2 + CHOCl and HCl + OH $\rightarrow$ H2O + Cl, are major reactions, through which OH radicals are consumed.

• 한국해양공학회지
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• 제11권3호
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• pp.76-88
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• 1997

Constant .DELTA.K fatigue crack growth rate experiments were performed by applying an intermediate single and multiple overload for structural steel, SM45C. The purpose of the present study is to investigate the influence of multiple overloads at various stress intensity factor ranges and the effect of statistical variability of crack retardation behavior. The normalized delayed load cycle, delayed crack length and the minimum crack growth rate are increased with increasing baseline stress intensity factor range when the overload ratio and the number of overload application were constant. The crack retardation under low baseline stress intensity factor range increases by increasing the number of overload application, but the minimum crack growth rate decreases by increasing the number of overload application. A strong linear correlation exists between the minimum crack growth rate and the number of overload applications. And, it was observed that the variability in the crack growth retardation behavior are presented, the probability distribution functions of delayed load cycle, delayed crack length and crack growth life are 2-parameter Weibull. The coefficient of variation of delayed load cycle and delayed crack length for the number of 10 overload applications data are 14.8 and 9.2%, respectively.