Analysis on Residents Recognition and Preference for Planning a Natural Recreation Forest Near City - Focused on Planning Mt. Wora Natural Recreation Forest in Jinju City -

Hyuncheol Heo,Inhea Kim,Eun Ju Jo,Keun Young Huh,Jonghoon Park 한국인간·식물·환경학회 2016 인간식물환경학회지 Vol.19 No.6

As a part of research to improve the satisfaction of residents on natural recreation forests near/within a city, the recognition of the residents was investigated and evaluated by using five-point Likert scale or frequency analysis for the plan of Mt. Wora natural recreation forest in Jinju city, which included the awareness, importance, preference, and visit intention of the residents. Until now, the personal goals of most visitors at Mt. Wora have been exercising or walking, and showed different from those of visitors at recreation forests with lots of recreational facilities and natural resources. Also the satisfaction was 3.6 and tended to be lower than that at natural recreation forests. The awareness and necessity of natural recreation forest were 3.3 and 4.0 respectively. As a result, the awareness was lower than the necessity though most respondent (84.5%) had already visited and experienced natural recreation forest before this survey. In the importance of facilities and programs, recreation/relaxation places, family accommodation, education, and leisure and sports were 4.2, 3.7, 3.7, and 3.4 respectively. The result shows a feature that the education was equal/similar to the family accommodation and the leisure and sports was over 3.0. In the preference of the types of accommodation and outdoor stay, the frequency of bungalow was 57.4% and higher than others. And then the frequency of autocamping and glamping were 36.5% and 32.9% respectively, and higher than that of camping. It indicates that users prefer more convenient types to typical/common types. The awareness and necessity of forest culture education were 3.1 and 4.1 respectively. The awareness of leisure and sports facilities was 3.2. The preference of adventures (zip line, eco-adventure etc.) was 3.4 and higher than those of others.

Users’ Recognition and Satisfaction of Trails and Exercise Facilities in Urban Mountainous Forests: Focused on Jinju City, South Korea

Keun Young Huh(Keun Young Huh),Hyuncheol Heo(Hyuncheol Heo),Hyunjong Jung(Hyunjong Jung),Inhea Kim(Inhea Kim) 인간식물환경학회 2022 인간식물환경학회지 Vol.25 No.5

Background and objective: This study was conducted to analyze users’ behavior, recognition, and satisfaction toward forest trails and exercise facilities in urban mountainous forests, Jinju City, South Korea. Methods: Users’ characteristics, visit motives, and satisfaction with forest trails and exercise facilities in three urban mountainous forests were surveyed from September to October 2020. The data of 300 respondents were analyzed using frequency, descriptive, and regression analysis. Results: There was a high percentage of users aged 51 or older (62.0%). Most users visited regardless of weekdays or weekends, every day or 2-3 times a week, and stayed for 1-2 hours. Most were using the forest trails and outdoor fitness facilities. Hiking or walking showed the highest frequency in visit motives, followed by using outdoor fitness facilities. Overall satisfaction with forest trails was high at 3.74-3.93 on a 5-point Likert scale, which was affected by the landscape and environment of small private arable lands around forest trails and convenient facilities such as handrails and information boards. Overall satisfaction with outdoor fitness facilities was 3.34-3.62, which was affected by harmony with forest landscape and facility maintenance. Overall satisfaction with indoor badminton courts was 3.01-3.08, which was affected by harmony with forest landscape. Conclusion: For improving overall satisfaction, it is crucial to maintain and repair the width and surface of forest trails, but renovating the landscape and environment of small private arable lands and exercise facilities may be more critical. It is desirable to improve and maintain the function and landscape of outdoor fitness facilities and to relocate indoor badminton courts to the outskirts or boundaries of the mountainous forests. To provide various leisure and recreation activities, the creation of a forest bathing place will be first necessary, followed by a family recreation place and outdoor learning classroom.

Sparse Structure-Based Channel Estimation for Uplink SCMA System

Heo, Eunhye,Kim, Namshik,Park, Hyuncheol IEEE 2017 IEEE Transactions on Vehicular Technology VT Vol.66 No.9

<P>To fully utilize the performance gain of sparse code multiple access (SCMA) system, the channel state information of multiusers must be obtained at the base station. However, conventional channel estimation approach causes significant training overhead as the number of active users becomes large. In this paper, we propose a channel estimation scheme for the uplink SCMA system to reduce the training overhead, which is based on the unstructured channel estimator (UCE). However, it is ineffective in terms of the resource usage to apply the UCE scheme to the SCMA system directly since the data detection requires only channel information on the nonzero subcarriers of the SCMA codeword. Thus, we introduce a sparse pilot structure where the location of nonzero pilot symbols correspond to the location of nonzero symbols in the SCMA codeword and provide an optimal pilot allocation scheme for the sparse pilot structure, which can achieve the mean square error lower bound. In addition, we consider the codebook reuse scenario to support more users with the existing SCMA codebooks. While the codebook reuse can help realize the massive connectivity, it has a problem that interference on each resource grows irregularly, which in turn leads to overwhelming training overhead. To solve this problem, we propose a channel estimation approach to reduce interference per subcarrier uniformly by the weight-regularization (WR) algorithm, and apply the optimal pilot allocation and least squares algorithm. The puncturing channel information by the WR algorithm can be obtained by a minimum mean square error (MMSE) interpolator or a combined interpolator. Analytical results and simulations shows effectiveness of the proposed channel estimators.</P>

Optimal fronthaul compression for synchronization in the uplink of cloud radio access networks

Heo, Eunhye,Simeone, Osvaldo,Park, Hyuncheol SpringerOpen 2017 Eurasip Journal on Wireless Communications and Net Vol.2017 No.-

<P>A key problem in the design of cloud radio access networks (CRANs) is to devise effective baseband compression strategies for transmission on the fronthaul links connecting a remote radio head (RRH) to the managing central unit (CU). Most theoretical works on the subject implicitly assume that the RRHs, and hence the CU, are able to perfectly recover time synchronization from the baseband signals received in the uplink, and focus on the compression of the data fields. This paper instead does not assume a priori synchronization of RRHs and CU, and considers the problem of fronthaul compression design at the RRHs with the aim of enhancing the performance of time and phase synchronization at the CU. The problem is tackled by analyzing the impact of the synchronization error on the performance of the link and by adopting information and estimation-theoretic performance metrics such as the rate-distortion function and the Cramer-Rao bound (CRB). The proposed algorithm is based on the Charnes-Cooper transformation and on the Difference of Convex (DC) approach, and is shown via numerical results to outperform conventional solutions.</P>

Fast Rayleigh Fading 환경에서의 IDMA에 관한 연구

허운정(Unjung Heo),박현철(Hyuncheol Park) 한국통신학회 2007 한국통신학회 학술대회논문집 Vol.2007 No.11

Improved Stopping Set Elimination by Parity-Check Matrix Extension of LDPC Codes

Saejoon Kim,Jun Heo,Hyuncheol Park IEEE 2011 IEEE communications letters Vol.15 No.5

<P>Stopping sets associated with a parity-check matrix of low-density parity-check codes limit the performance of iterative decoding over the binary erasure channel. In this letter, we propose a parity-check matrix extension scheme that eliminates stopping sets of small sizes. The results show that our proposed scheme provides significant performance improvement compared to previously known parity-check matrix extension schemes.</P>