• 대한안전경영과학회지
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• 제24권3호
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• pp.23-28
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• 2022

Rack is a place to store products. Workers pick products from rack storage. After picking up, workers move to another location by forklift. Driving speed, worker condition, and number/frequency of operation is responsible for forklift accidents. When an accident occurs, products get damaged. Therefore, it is important to prevent one. As the research result, To prevent forklift accidents, the minimum order quantity, the minimum number of operations, and low speed operation are required.

• 품질경영학회지
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• 제46권4호
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• pp.899-910
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• 2018

Purpose: Generally, since the population density is lower in suburban areas, the distance to school is inevitably long. Therefore, schools in suburban areas often operate school buses to improve student welfare. However, since school buses are usually used only during going to and from school, the utilization rates are relatively low. Therefore, this study aims to establish integrated operation plan of public school bus covering all schools. Methods: It is necessary to decide which school buses will serve the specific demand node which want to go to certain school in order to design an integrated operation plan for school buses. Therefore, a mathematical model is developed for minimizing the total number of vehicles and the distance of transportation by reflecting the characteristics of school buses and students as constraints. To solve the proposed mathematical model, CPLEX, a commercial solver, is applied. Results: To validate and to confirm the proposed process, numerical example is designed with the comparison between before and after integrated operations of school buses in terms of total operation cost. The result shows that the integrated operation can lead the reduction of the number of school buses as well as the decreasing of the fuel cost. Conclusion: This study provides the quantitative method to perform the integrated operation of school buses in suburban areas. The optimal operation strategy is required because there are more complex decision-making elements considering the integrated operation. It is expected to apply this research result at real situation to expand this services based on an optimal operation.

• 한국컴퓨터정보학회논문지
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• 제10권5호
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• pp.87-94
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• 2005

본 논문은 자동차 차량의 컬러 영상 이미지에서 신속하고 효율적으로 번호판 영역을 찾는 방법에 대한 연구이다. 일반적으로 자동차 번호판 영역은 차량의 종류에 따라 일정한 색상을 가지고 있다. 이에 일정한 색상영역을 찾기 위해 HSI 컬러모델의 색상 성분 H와 YIQ 컬러 모델의 색상 성분 Q를 결합하는 방식을 사용한다. 그러나 이러한 방법을 사용하면 전체 연산시간이 많이 걸리게 되는 단점이 존재한다. 그러므로 본 논문에서는 차량 번호판 영역을 추출하는 단계들 중에서 H와 Q 색상 성분을 추출하면서 후보영역 추출 연산을 병행 수행한다. 이 단계가 끝나면 H와 Q성분을 결합하는 단계에서 전체 이미지 픽셀 정보를 대상으로 비교연산을 수행하지 않고 각 단계에서 추출된 후보영역들만을 비교 연산함으로써 영역 추출을 빠르게 수행할 수 있다 이에 대한 각 단계별 시스템 처리 결과 화면을 보이고 이미지 해상도에 따른 추출 시간을 비교하였다.

• 한국학교수학회논문집
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• 제17권2호
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• pp.235-249
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• 2014

본 논문에서는 우리나라와 일본의 초등학교 1학년 수학 교과서 <수와 연산> 영역을 비교하고 있다. 그 결과를 바탕으로 우리나라의 초등학교 1학년 수학 교과서 <수와 연산> 영역의 개선을 위해 얻은 시사점은 다음과 같다. 첫째, 두 자리 수의 구성을 설명할 때 먼저 구체물로 나타낸 것을 수학적 표현으로 바꾸고, 그 다음에 그것을 수학적으로 처리하는 것을 고려할 필요가 있다. 둘째, 수의 합성과 분해와 관련하여, '(몇)과 (몇)'이라는 표현을 사용하는 것을 고려할 필요가 있다. 셋째, 등호가 있는 덧셈식과 뺄셈식을 읽을 때, 각각 '합'과 '차'를 사용하여 읽는 방식을 재고할 필요가 있다. 넷째, 첨가 상황과 합병 상황, 제거 상황과 비교 상황을 각각 구별해 주는 표현의 사용을 고려할 필요가 있다. 다섯째, 받아내림이 있는 (십 몇)-(몇)을 설명하기 위해 두 수의 뺄셈을 세 수의 뺄셈 또는 세 수의 혼합산으로 표현하는 과정에서 나타나는 비약을 해소할 필요가 있다.

• 융합신호처리학회논문지
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• 제12권2호
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• pp.139-144
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• 2011

The modern digital logic technology does not yet satisfy the speed requirements of real-time DSP circuits due to synchronized operation of multiplication and accumulation. This operation degrades DSP performance. Therefore, the double-base number system (DBNS) has emerged in DSP system as an alternative methodology because of fast multiplication and hardware simplicity. In this paper, authors propose a novel multiplication architecture. One operand is an output of a flash analog-to-digital converter (ADC) in DBNS format, while the other operand is a coefficient in the IEEE standard floating-point number format. The DBNS digital output from ADC is produced through a new double base number encoder (DBNE). The multiplied output is in the format of the IEEE standard floating-point number (FPNS). The proposed circuits process multiplication and conversion together. Compared to a typical multiplier that uses the FPNS, the proposed multiplier also consumes 45% less gates, and 44% faster than the FPNS multiplier on Spartan-3 FPGA board. The design is verified with FIR filter applications.

• 한국산업보건학회지
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• 제20권1호
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• pp.10-18
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• 2010

To provide necessary information for future environmental monitoring of smelting and litharge making industries in Korea, environmental monitoring dataset of air lead concentration of 4 lead industries(1 primary smelting, 2 secondary smelting and 1 litharge making industry) were analyzed from 1994 to 2007. Data were compared using geometric mean and standard deviation with minimum and maximum values according to year of measurement, type of lead industries and type of operation of lead industries. The geometric mean and standard deviation of air concentration for a total of 1140 samples in all lead industries for overall 14 years were 70.7${\mu}g/m^3$ and 5.51 with minimum of 1${\mu}g/m^3$ and maximum of 9,185 ${\mu}g/m^3$. The overall geometric means of air concentration were above the permissible exposure levels(PEL) until year of 2001 and thereafter they were remained at the level of half of PEL. The geometric means of primary smelting, secondary smelting and litharge making industry for overall 14 years were 21.7${\mu}g/m^3$(number of samples: 353), 82.5${\mu}g/m^3$(number of samples: 357) and 164.2 ${\mu}g/m^3$(number of samples: 430) respectively. In primary smelting industry, the highest geometric mean air concentration was 35.4 ${\mu}g/m^3$ in the secondary smelting operation; followed by casting operation (24.9 ${\mu}g/m^3$) and melting operation (14.9 ${\mu}g/m^3$), respectively. On the other hand, in secondary smelting industries, the highest geometric mean air concentration was 125.4${\mu}g/m^3$ in melting operation; followed by casting operation (90.5${\mu}g/m^3$) and pre-treatment operation (43.4${\mu}g/m^3$), respectively. However, in litharge making industries, there were no significant differences of geometric mean air concentrations between litharge operation and stabilizer operation. The proportion of over PEL (50${\mu}g/m^3$) was highest in litharge industry and followed by secondary smelting industries. However The proportions of over PEL(${\mu}g./m^3.$) were decreased by the years of environmental monitoring. The significant reduction of mean air lead concentration since year of 2000 was observed due to more active environmental engineering control and new introduction of new operation in manufacturing process, but may be also influenced by non-engineering method such as reduction of operation hours or reduction of exposure time during actual environmental measurement by industrial hygienist according to more strict enforcement of occupational and safety law by the government.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.195-198
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• 2000

It is possible to perform the digital fuzzy logical high-speed and high-precision computation by the use of redundantly-represented binary positive-digit number arithmetic operation. In this paper, as basic operation circuits in the fuzzy logic new voltage-mode 4-valued binary parallel processing operation circuits using positive redundantly-expressed binary-coded numbers is discussed.

• 한국항해항만학회지
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• 제30권9호
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• pp.741-748
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• 2006

Number of researches on efficient terminal operation system applying RFID(Radio Frequency Identification) are in progress. However, RFID has limitations on tracking and providing accurate positions of containers. In this paper, to enhance the performance of the integrated terminal operation system, an efficient loading management of yard is proposed by applying RFID based RTLS(Real Time Locating System) that provides real time accurate positions of containers. It was found that a group based sequence system is more efficient than the existing individual sequence number system in the container yard In the group based sequence system, the containers in the same group should have similar characteristics such as port of destination(POD), size, weight, etc. In order to run this system, we proposed the parameters to the unspecified N bytes of RFID tag which are specified in ISO 18000 7. And then, we developed an integrated operation system of container terminal using RFID. The proposed system reduces the ship turnaround time in ubiquitous port environments.

• East Asian mathematical journal
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• 제29권4호
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• pp.355-392
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• 2013

Generally school algebra is to start with introducing variables and algebraic expressions, which have major cognitive obstacles to students in the transfer from arithmetic to algebra. But the recent studies in the teaching school algebra argue the algebraic thinking from an early algebraic point of view. We compare the Korean elementary mathematics textbooks with Americans from this perspective. First, we discuss the history of school algebra in the school curriculum. And Second, we investigate the recent studies in relation to early algebra. We clarify the goals of this study(the importance of early algebra in the elementary school) through these discussions. Next we examine closely the number sense in the arithmetic and the symbol sense in the algebra. And we conclude that the operation sense can connect these senses within early algebra using the algebraic thinking. Finally, we compare the elementary mathematics books between Korean and American according to the components of the operation sense. In this comparative study, we identify a possibility of teaching algebraic thinking in the elementary mathematics and early algebra can be introduced to the elementary mathematics textbooks from aspects of the operation sense.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.343-348
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• 2006

Number of researches on efficient terminal operation system applying RFID(Radio Frequency Identification) are on progress. However, RFID has limitations on tracking and providing accurate positions of containers. In this paper, to enhance the performance of the integrated terminal operation system, an efficient loading management of yard is proposed by applying RFID-based RTLS(Real Time Locating System) that provides real-time accurate positions of containers. We found that a group-based sequence system is more efficient than the existing individual sequence number system in the container yard. In the group-based sequence system, the containers in the same group should have similar characteristics such as port of destination(POD), size, weight, etc. In order to run this system, we have proposed the parameters to the unspecified N bytes of RFID tag which are specified in ISO 18000-7. And, this paper proposed a development of integrated operation system of container terminal using RFID for reducing the ship turnaround time in ubiquitous port environment.