• Journal of Positioning, Navigation, and Timing
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• 제10권1호
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• pp.49-54
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• 2021

Indoor positioning system becomes of increasing interests due to the demands for accurate indoor location information where Global Navigation Satellite System signal does not approach. Wi-Fi access points (APs) built in many construction in advance helps developing a Wi-Fi Received Signal Strength Indicator (RSSI) based indoor localization. This localization method first collects pairs of position and RSSI measurement set, which is called fingerprint database, and then estimates a user's position when given a query measurement set by comparing the fingerprint database. The challenge arises from nonlinearity and noise on Wi-Fi RSSI measurements and complexity of handling a large amount of the fingerprint data. In this paper, machine learning techniques have been applied to implement Wi-Fi based localization. However, most of existing indoor localizations focus on single position estimation. The main contribution of this paper is to develop multi-target localization by using deep neural, which is beneficial when a massive crowd requests positioning service. This paper evaluates the proposed multilocalization based on deep learning from a multi-story building, and analyses its learning effect as increasing number of target positions.

• Near Infrared Analysis
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• 제2권1호
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• pp.37-42
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• 2001

Near infrared spectroscopy (NIRS) was applied to determination of the lipid content of the compost during the compost fermentation of tofu (soybean0curd) refuse. The absorption of lipid observed at 5 wavelengths, 1208, 1712, 1772, 2312 and 2352 nm on the second derivative spectra. To formulated a calibration equation, a multiple linear regression analysis was carried out between the near-infrared spectral data and on the lipid content in the calibration sample set (sample number, n=60) obtained using Soxhlet extraction method. The value of the multiple correlation coefficient (R) was 0.975 when using the wavelengths of 1208 and 1712 nm were used in the calibration equation. To validate the calibration equation obtained, the lipid content in the validation sample set (n=35) not used for formulating the calibration equation was calculated using the calibration equation, and compared with the value obtained using the Soxhlet extraction method. Good agreement was observed between the results of the Soxhlet extraction method and those values of the NIRS method. The simple correlation coefficient (r) and standard error of prediction (SEP) were 0.964 and 0.815 %, respectively. suitability of the lipid content as an indicator of the compost fermentation of tofu refuse was also studied. The decrease of the lipid content in the compost corresponded to the decrease of the total dry weight of the compost in the composter. The lipid content was a significant indicator of the compost fermentation. The NIRS method was applied to measure the time course of the lipid content in the compost fermentation and good results were obtained. The study indicates that NIRS is a useful method for process management of the compost fermentation of tofu refuse.

• 대한공간정보학회지
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• 제16권3호
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• pp.43-49
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• 2008

실시간 위치추적 (Real Time Location System ; RTLS) 시스템은 유비쿼터스 사회에서 인물, 자산, 물류제품을 실시간으로 추적하기 위해 매우 중요하다. 본 연구에서는 RTLS를 위해 능동형 RF 시스템을 개발하였고 개발된 시스템의 성능을 측정하였다. 본 시스템에서 개발한 RTLS 시스템은 3개의 능동형 리더(수신기)와 1개의 태그로 구성되었다. 개발된 능동형 소형 태그에는 동전형 배터리를 내장하였다. 태그의 소형화를 위해 내장형 PCB 안테나와 칩 안테나를 장착하여 태그의 성능을 측정하였다. 또한, RF 시스템의 제조 원가를 줄이기 위해 저가의 RF 트랜시버 CC2510 칩셋을 사용하였다. CC2510 칩셋은 능동형 태그와 능동형 리더 (수신기)사이의 거리를 측정하기 위한 수신신호 강도지시기가 (Received Signal Strength Indicator ; RSSI) 내장되어있다.

• 농촌지도와개발
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• 제22권2호
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• pp.135-144
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• 2015

Competitiveness has been associated in the tourism literature as a crucial factor for the success of tourist destinations. This study is to develop indicators that measure destination competitiveness of rural tourism townships in Korea. It was conducted via a Delphi technique and the analytical hierarchy process method. After four rounds of discussions, the panel members reached consensus on a set of 27 indicators with three dimensions which are attractor (resource, infrastructure, and tourism products), assistance (tourism business assistance and value-added processing assistance), and planning and management (planning for development, capacity for management). This set of destination competitiveness indicators can serve as a starting point for devising a set of indicators at the local level in order to be useful rural tourism sector manager and administrators. The selected indicators are measurable, demand driven and practical to show the real performance in rural destination.

• 농촌계획
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• 제20권2호
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• pp.1-10
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• 2014

Smartphones change the picture of data and information sharing and make it possible to share various real-time flooding data and information. The vulnerability indicators of farmland inundation is needed to calculate the risk of farmland flood based on changeable hydro-meteorological data over time with morphologic characteristics of flood-damaged areas. To find related variables show the vulnerability of farmland inundation using the binary-logit model and correlation analysis and to provide vulnerability indicators were estimated by fuzzy set method. The outputs of vulnerability indicators were compared with the results of Monte Carlo simulation (MCS) for verification. From the result vulnerability indicators are applicable to mobile_based information system of farmland inundation.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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• pp.883-887
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• 2011

Location-based service (LBS) is becoming an important part of the information technology (IT) business. Localization is a core technology for LBS because LBS is based on the position of each device or user. In case of outdoor, GPS - which is used to determine the position of a moving user - is the dominant technology. As satellite signal cannot reach indoor, GPS cannot be used in indoor environment. Therefore, research and study about indoor localization technology, which has the same accuracy as an outdoor GPS, is needed for "seamless LBS". For indoor localization, we consider the IEEE802.11 WLAN environment. Generally, received signal strength indicator (RSSI) is used to obtain a specific position of the user under the WLAN environment. RSSI has a characteristic that is decreased over distance. To use RSSI at indoor localization, a mathematical model of RSSI, which reflects its characteristic, is used. However, this RSSI of the mathematical model is different from a real RSSI, which, in reality, has a sensitive parameter that is much affected by the propagation environment. This difference causes the occurrence of localization error. Thus, it is necessary to set a proper RSSI model in order to obtain an accurate localization result. We propose a method in which the parameters of the propagation environment are determined using only RSSI measurements obtained during localization.

• 전자공학회논문지SC
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• 제46권2호
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• pp.7-14
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• 2009

본 논문에서는 불확실성을 가지는 비선형 시스템에 대한 강인 유한 시간 안정화 문제를 고려한다. 불확실성은 시변 외란 혹은 이미 알고 있는 옹골 집합에 포함된 파라미터들이다. 제안된 설계기법은 역진기법(backstepping)과 추가된 다이나믹스를 이용한 다이나믹 지수 보정법(dynamic exponent scaling)에 기반을 두고 있으며, 이로부터 다이나믹 스무스 궤환 제어기(dynamic smooth feedback controller)가 유도된다. 페루프 시스템의 유한 시간 안정과 제어기의 유한함은 각각 유한 시간 안정에 관한 리아푸노프 안정 이론과 새로운 개념인 '차수 지표자(degree indicator)'를 이용하여 증명된다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.195-196
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• 2019

최근 경제의 불확실성이 커지면서 매출 확대를 기대하기 힘든 상황에서 운영비용을 줄이기는 쉽지 않은 상황이다. 저비용으로 서비스 수준을 올려 시장에서의 경쟁우의를 지켜야 하는 물류센터 입장에서는 저렴한 비용으로 서비스 수준을 획기적으로 향상시킬 수 있는 방안이 필수적이다. 본 연구에서는 KPI (Key Performance Indicator) 분석을 통해 물류운영시스템 전체 프로세스를 대상으로 효율적인 물류 운영을 하고 있는지를 판단하고, 성과지표를 중심으로 고객만족도를 높일 수 있도록 각 항목을 설정하여 측정하고 개선해야 함을 시사하고 있다.

• International Journal of Quality Innovation
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• 제10권1호
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• pp.77-87
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• 2009

The main aim of the paper is to provide an empirical analysis on patient satisfaction as an indicator of service quality in Malaysian public hospitals. Self-administered questionnaires were administered to patients by convenience sampling. Two sets of questionnaires were used, one for inpatient and another one set for outpatient. Selection of hospitals was made according to states in Peninsular Malaysia. 23 hospitals covering all state level hospitals, the National Referral Centre and selected district hospitals were chosen as respondent hospitals. Two dimensions of service quality emerged, namely clinical and physical dimension of service. Both outpatient and inpatient were found to be more satisfied with clinical dimension of service than physical dimension. For outpatient satisfaction, there was positive correlation between waiting time and patient satisfaction. Patient satisfaction was also found to be higher in the smaller district hospitals than in the larger state hospitals. For clinical dimension of service, patients were satisfied with the services of doctors and nurses, while for physical dimension of service, patients were satisfied with the cleanliness of the facilities. The ability of the research to be conducted by random sampling was inhibited by the reluctance of patients to cooperate, which led to the use of convenience sampling. Studies have also shown that patients are reluctant to express their feelings on services provided by their caregivers. The study provides primary data for a nationwide study on patient satisfaction in Malaysian public hospitals, for both inpatient and outpatient.

• 센서학회지
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• 제13권1호
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• pp.47-55
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• 2004

This paper presents drug release properties of active drug delivery system (DDS) using volume change of polypyrrole (PPy). The incorporation of various chemical substances into the PPy and controlling its release with the externally applied voltage to the PPy are possible. In order to confirm possibility for drug delivery system qualitatively, indicator(phenol red) was examined as a dopant of PPy. The applied voltage to the PPy electrode was set to -2 V and this negative voltage makes the anionic indicator released in saline solution. After qualitative analysis, in order to confirm quantitative drug release characteristic of PPy, salicylate which is one of the aspirin substance was used as a dopant of PPy. As a result, the salicylate release characteristics with time was thoroughly investigated while varying the electrode area, polymerization time, the applied voltage for drug release. Based on these quantitative results, a preliminary experiment was carried out to check the feasibility of the PPy applicable to the neuronal system.