• Journal of information and communication convergence engineering
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• v.17 no.2
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• pp.142-148
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• 2019

Relatively few countries provide separate bicycle lanes for cyclists. Hence, tools for suggesting cycling routes are essential for a safe and pleasant cycling experience. This study aims to develop a mobile application to build cycling routes based on user preferences, specifically location, search radius, ride distance, and number of optimal routes. Our application calls the Strava API to retrieve Strava cycling segments crowdsourced from the cycling community. Then, it creates a graph consisting of the start and end points of these segments. Beginning from a user-specified location, the depth-first search algorithm (DFS) is applied to find routes that conform to the user's preferences. Next, a set of optimal routes is obtained by computing a trade-off ratio for every discovered route. This ratio is calculated from the lengths of all segments and the lengths of all connecting paths. The connected routes can be displayed on a map on an Android device or exported as a GPX file to a bike computer. Future work must be performed to improve the design of the user interface and user experience.

• Journal of Ocean Engineering and Technology
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• v.8 no.1
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• pp.62-70
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• 1994

In order to estimate the detection range of a active SONAR system, the SONAR equation is commonly used. In this paper, an algorithm to calculate detection range in active SONAR system as function of SONAR depth and target depth is presented. For given SONAR parameters and environment, the transmission loss and background level are found, signal excess is computed. Using log-normal distribution, signal excess is converted to detection probability at each range. Then, the detection range is obtained by integrating the detection probability as function of range for each depth. The proposed algorithm have been applied to the case of omni-directional source with center frequency 30Hz for summer and winter sound profiles. It is found that the optimal search depth is the source depth since the detection range increase at source depth where the signal excess is maximized.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.294-299
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• 2007

Natural gypsum has been used as a soil amendment in the United States. However, flue gas desulfurization (FGD)-gypsum has not traditionally been used for agricultural purpose although it has potential benefit as a soil amendment. To expand use of FGD-gypsum for agricultural purpose, the effect of FGD-gypsum on soil chemical properties was investigated in the field scales. Application rates for this study were 0 (control), 1.1, and 2.2 Mg ha-1 of FGD-gypsum. After two year application, the soil samples were taken to 110 cm depth and sub-sampled at 10 cm intervals. The heavy metal contents in FGD-gypsum were lower than ceiling levels allowed by regulations for land-applied biosolids. Soil pH was not largely affected by FGD-gypsum application. Although degree of calcium (Ca) saturation in surface horizons increases only slightly with respect to the control, there is a clear decrease in exchangeable aluminum (Al). FGD-gypsum clearly increases the soil electrical conductivity (EC) with increasing application rate. Water-soluble Ca and sulfate is increased with FGD-gypsum application and these ions moved to a depth of at least 80 cm after only 2 years. We conclude that surface application of FGD-gypsum can mitigate toxicity of Al and deficiency of Ca in subsoil of acid soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.370-375
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• 1996

This study was conducted to find out the feasibility in direct seeded rice cultivation on the reclaimed saline soil. Seedling emergence was tested under the different application rates of rice straw and seeding depth, and also under combined treatments soil moisture regimes and seeding depth on saline soils in a greenhouse. The comparison of seedling stand and yield performance of rice in rotary till after broadcast seeding and in non-plow after broadcast seeding were tested on a field that reclaimed saline soil. Seedling emergence ratio in application of rice straw(4 and 6 tons /ha) was higher than that in non-application of rice straw. Seedling emergence and plant height were remarkably increased with the shallow seeding depth in the application of rice straw(4 tons /ha). The seedling emergence under proper soil moisture condition(25%) was higher than that under excess soil moisture condition(35%). Under proper soil moisture condition, the plant height was increased with the shallowed seeding depth. The number of seedling stand per m$^2$ in non-plow after broadcast seeding was larger than that in rotary till after broadcast seeding. Panicle number per m$^2$ in non-plow after broadcast seeding was much larger than that in rotary till after broadcast seeding and the yield showed the same trends as panicle number.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.253-256
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• 2021

본 논문에서는 합성곱 신경망을 통해 학습된 DoF(피사계 심도, Depth of field) 네트워크 아키텍처를 이용하여 객체 인식, 시점 추적, 문자 인식, 비사실적 렌더링 등 다양한 애플리케이션에 적용할 수 있는 사후 필터링 기법에 대해 살펴본다. 일반적으로 영상은 포커싱과 아웃포커싱에 의해 사용자의 관심표현이 결정되며, 이를 이용하여 영상 내 중요도를 판단한다. 영상 내에는 수많은 콘텐츠들이 혼재되어 있기 때문에 사용자가 집중적으로 보고 있는 콘텐츠를 찾아내기 어렵다. 본 논문에서는 사용자가 흥미롭고 집중적으로 보고 있는 영역을 DoF 네트워크로 학습시키고, 이를 통해 이전 기법으로는 표현할 수 없었던 DoF 기반 객체 인식, 시점 추적, 문자 인식, 비사실적 렌더링을 효율적으로 표현해낸다.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.1
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• pp.41-47
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• 2011

Residual stress is the key parameter for reliability and lifetime assessment because it can reduce the fatigue strength and fracture properties of industrial structures. Recently, instrumented indentation testing (IIT) has been widely used for evaluating it, since it does not need specific specimen and time-consuming procedure. However, conventional Oliver-Pharr method, which is used for calibrating contact depth to analyze indentation load-depth curve, cannot estimate plastic pile-up between indenter and surface of specimen. Here, we introduce f parameter which is the ratio of contact depth and maximum depth, to consider pile-up height. And, its application for evaluating residual stress of weldment is introduced.

• Journal of Ocean Engineering and Technology
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• v.20 no.1 s.68
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• pp.43-47
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• 2006

Superposition of three wave trains on finite depth is investigated. This paper is focused on how to improve the linear superposition of three waves. This was realized by introducing the scheme. The idea of the scheme is based on a fixed point approach. Application of the scheme to the superposition makes it possible to obtain a wave profile of wave-wave interaction. With the help of FFT, it was possible to analyze high-order nonlinear frequencies for three interacting Stokes' waves on finite depth.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.249-252
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• 2005

Recently, as the industrial demand for small quantity batch production of sheet metal components, the application of dieless forming technology to production of these component rise with the advantages of the reduction in manufacturing cost and time. In dieless forming processes, the determination of moving path of tool plays an important role in producing successfully formed parts. In order to obtain the optimized moving path of tool avoiding forming failure, it is necessary to examine the forming limit of sheet material. Therefore, in this study, as the new criterion to evaluate the formability of sheet material in dieless forming processes FDD(feeding depth diagram) with respect to feeding depth and punch diameter is proposed. Thus, the FDD for the sheet materials of STS304 and Ti-grade2 were obtained from a series of FDT(feeding depth test). In addition the possibility of the application of FLD in judging forming severity in dieless forming processes was investigated by comparing the results of FE analyses based on FLD and experimental FDT.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.144-145
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• 2005

In this study, we have developed the high resolution multichannel seismic data acquisition system and shallow marine seismic source. It is easy to operate our source system which utilizes piezoelectric transducer of high electrical power. According to water depth, survey condition and purpose, transducer number of source system can be easily changed in order to maximize field applicability. In the recording part, we used 24 bits and 8 channel high speed A/D board in order to achieve the improvement of data quality and the efficiency of data acquisition. The developed system was tested and varied with the data acquisition parameters such as source-receiver offset, and transducer number versus water depth for the field application.

• Journal of Information Technology Services
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• v.21 no.1
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• pp.163-179
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• 2022

Two dominant phenomena in modern world; population ageing and digitalization, have led public sector organizations to heavily rely on B2C(Business-to-Consumer) mobile applications. Yet, fatal concerns and complaints have often been raised by the mobile application users, notably from social welfare sector. With the continual expansion of digital landscape as well as the growth of life expectancy, usage of mobile applications has become prevalent across the stakeholders involved in social welfare sector. 'Smart Long-Term Care (SLTC)', inter alia, is a primary example of such mobile applications, designed to support Long-Term Residential Care (LTRC) service. The main goal of SLTC is to serve more convenient and practical LTRC service for both caregivers and care receivers. To examine user satisfaction of SLTC mobile application, this study investigates existing challenges and means to improve user satisfaction. Hence, we conducted this study using two methods: in-depth interview and topic modeling. Interestingly, two research outcomes commonly indicated that 5 factors (stability, accessibility, usefulness, responsiveness, and ease of use) were found significant in affecting user satisfaction of SLTC. Our findings suggest that the aforementioned factors can be seen as potential causes of the genuinely low user satisfaction. Eventually, this work will be a stepping-stone to elevate the overall quality level of LTRC service along with the user satisfaction degree of SLTC mobile application.