Applying nano-HA in addition to scaling and root planing increases clinical attachment gain

Özge Uysal,Gülbahar Ustaoğlu,Mustafa Behçet,Önder Albayrak,Mustafa Tunalı 대한치주과학회 2022 Journal of Periodontal & Implant Science Vol.52 No.2

Purpose: This study evaluated the efficacy of treating periodontitis using subgingival nanohydroxyapatite powder with an air abrasion device (NHAPA) combined with scaling and root planing (SRP). Methods: A total of 28 patients with stage III periodontitis (grade B) were included in this study, although 1 was lost during follow-up and 3 used antibiotics. The patients were divided into a test group and a control group. All patients first received whole-mouth SRP using hand instruments, and a split-mouth approach was used for the second treatment. In the test group, the teeth were treated with NHAPA for 15 seconds at 70% power per pocket. Subgingival plaque samples were obtained from the 2 deepest pockets at the test and control sites before treatment (baseline) and 3 months after treatment. The full-mouth plaque index (PI), gingival index (GI), papillary bleeding index (PBI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and at 1- and 3-month post-treatment. Real-time polymerase chain reaction was used to determine the colonisation of Treponema denticola (Td), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans in the subgingival plaque. Results: From baseline to the first month, the test group showed significantly larger changes in BOP and CAL (43.705%±27.495% and 1.160±0.747 mm, respectively) than the control group (36.311%±27.599% and 0.947±0.635 mm, respectively). Periodontal parameters had improved in both groups at 3 months. The reductions of PI, GI, BOP, PD, and CAL in the test group at 3 months were greater and statistically significant. The total bacterial count and Td and Pg species had decreased significantly by the third month in both groups (P<0.05). Conclusions: Applying NHAPA in addition to SRP improves clinical periodontal parameters more than SRP alone. Subgingival NHAPA may encourage clot adhesion to tooth surfaces by increasing surface wettability.

An Energy-Efficient MAC Protocol for Wireless Wearable Computer Systems

Beh, Jounghoon,Hur, Kyeong,Kim, Wooil,Joo, Yang-Ick The Korea Institute of Information and Commucation 2013 Journal of information and communication convergen Vol.11 No.1

Wearable computer systems use the wireless universal serial bus (WUSB), which refers to USB technology that is merged with WiMedia physical layer and medium access control layer (PHY/MAC) technical specifications. WUSB can be applied to wireless personal area network (WPAN) applications as well as wired USB applications such as PAN. WUSB specifications have defined high-speed connections between a WUSB host and WUSB devices for compatibility with USB 2.0 specifications. In this paper, we focus on an integrated system with a WUSB over an IEEE 802.15.6 wireless body area network (WBAN) for wireless wearable computer systems. Due to the portable and wearable nature of wearable computer systems, the WUSB over IEEE 802.15.6 hierarchical medium access control (MAC) protocol has to support power saving operations and integrate WUSB transactions with WBAN traffic efficiently. In this paper, we propose a low-power hibernation technique (LHT) for WUSB over IEEE 802.15.6 hierarchical MAC to improve its energy efficiency. Simulation results show that the LHT also integrates WUSB transactions and WBAN traffic efficiently while it achieves high energy efficiency.

Dual channel based speech enhancement using novelty filter for robust speech recognition in automobile environment

Beh, Jounghoon,Baran, R.H.,Ko, Hanseok IEEE 2006 IEEE transactions on consumer electronics Vol.52 No.2

In this paper, a simple and effective dual channel speech enhancement algorithm is proposed. The proposed algorithm incorporates a novelty filter scheme, performing associative memory and aiming at improving the performance of the dual channel generalized sidelobe canceller (GSC.) The novelty filter is demonstrated as effective for enhancing the reference noise used in the dual channel GSC, such that the assumptions required for adaptive noise cancellation are satisfied. In this paper, the concept of a novelty filter scheme is described, in addition to the conditions required to guarantee, the performance of the dual channel GSC and the method of applying the novelty filter scheme to speech enhancement objectives. In representative experiments, superiority of the proposed algorithm is demonstrated using three objective measures; segmental signal to noise ratio (SNR), log spectral distance (LSD) and word accuracy, which are evaluated via speech data recorded in real automobile environments.

Harmonics-based Spectral Subtraction and Feature Vector Normalization for Robust Speech Recognition

Beh, Jounghoon,Lee, Heungkyu,Kwon, Ohil,Ko, Hanseok 한국음성과학회 2004 음성과학 Vol.11 No.1

In this paper, we propose a two-step noise compensation algorithm in feature extraction for achieving robust speech recognition. The proposed method frees us from requiring a priori information on noisy environments and is simple to implement. First, in frequency domain, the Harmonics-based Spectral Subtraction (HSS) is applied so that it reduces the additive background noise and makes the shape of harmonics in speech spectrum more pronounced. We then apply a judiciously weighted variance Feature Vector Normalization (FVN) to compensate for both the channel distortion and additive noise. The weighted variance FVN compensates for the variance mismatch in both the speech and the non-speech regions respectively. Representative performance evaluation using Aurora 2 database shows that the proposed method yields 27.18% relative improvement in accuracy under a multi-noise training task and 57.94% relative improvement under a clean training task.

Spectral Subtraction Using Spectral Harmonics for Robust Speech Recognition in Car Environments

Beh, Jounghoon,Ko, Hanseok The Acoustical Society of Korea 2003 韓國音響學會誌 Vol.22 No.e2

This paper addresses a novel noise-compensation scheme to solve the mismatch problem between training and testing condition for the automatic speech recognition (ASR) system, specifically in car environment. The conventional spectral subtraction schemes rely on the signal-to-noise ratio (SNR) such that attenuation is imposed on that part of the spectrum that appears to have low SNR, and accentuation is made on that part of high SNR. However, these schemes are based on the postulation that the power spectrum of noise is in general at the lower level in magnitude than that of speech. Therefore, while such postulation is adequate for high SNR environment, it is grossly inadequate for low SNR scenarios such as that of car environment. This paper proposes an efficient spectral subtraction scheme focused specifically to low SNR noisy environment by extracting harmonics distinctively in speech spectrum. Representative experiments confirm the superior performance of the proposed method over conventional methods. The experiments are conducted using car noise-corrupted utterances of Aurora2 corpus.

MAP Adaptation with Mixtures of von Mises Distributions and Its Application to Underdetermined Convolutive Blind Source Separation

Jounghoon Beh(배정훈) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.10

본 논문에서는 시간-주파수 영역에서 음원분리를 위해 도달음원의 위상차 분포 추정을 위한 최대 사후 확률 기반의 파라미터 적응기법을 제안한다. 도달 음원의 위상차 데이터는 혼합 폰 미제스 분포로 가정하여 음원의 각도 위치에 따라 분류되었으며, 이 혼합 폰 미제스 분포는 위상차와 같은 2π 순환 데이터를 모델링할 때 효과적이다. 제안한 방법은 혼합 음원의 스펙트로그램 상에서 시간 및 주파수 구간을 각각의 음원으로 클러스터링하는 용도에 사용되었으며, 이는 마스크 기반 블라인드 음원 분리기술에서 가장 핵심적인 부분이다. 혼합 폰 미제스 분포로 모델링 된 도달음원위상차 분포의 파라미터들을 안정적으로 추정하기 위하여, 먼저 각 도착 신호의 각도 분포를 구성하였으며, 이 각도 분포를 바탕으로 각 주파수 밴드의 위상차 분포를 나타내는 파라미터들을 각각의 주파수 대역 별로 추정하였다. 이를 바탕으로 스펙트로그램상에서 음원별로 시간-주파수 영역을 구분하고 이 영역들은 시간-주파수 마스크를 생성하는데 쓰여졌다. 제안한 방법은 SiSEC 2008 데이터셑을 이용하여 다양한 신호 대 잡음비 값으로 평가되었으며, 그 타당성이 입증되었다. In this paper, we propose a Maximum a Posteriori (MAP) adaptation method for the parameter of Phase Difference of Arrival (PDOA) distribution to classify sound sources in the time-frequency domain. The PDOA is clustered via Mixtures of von Mises distribution (MovM) which is efficacious in modeling a 2 circular domain. The proposed method is employed to the task of clustering a spectral bin in terms of a sound source, which is a crucial part of the mask-based blind source separation. To robustly estimate the model parameter of MovM of the PDOA, we first build an incidence angle distribution and then adapt the parameters to each frequency band. The clustered spectral bin is used to build a time-frequency (TF) mask to separate the mixed audio signal based on the signal sparseness property.

Parameter Estimation of Source Image Using Least-Squares for Dual Channel Underdetermined Convolutive Blind Speech Separation

Jounghoon Beh(배정훈) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.10

칵테일 파티 문제를 해결하기 위한 일환으로서 블라인드 음원 분리 기술은 군사용 인공지능 활용 분야에서 오랫동안 연구되어왔다. 칵테일 파티 문제는 언어이해를 목적으로 하는 지능 시스템이 다양한 음원이 존재하는 상황에서 타겟사용자의 목소리를 분간해 내지 못하여 사용자 명령을 이해하지 못하는 현상을 말한다. 본 논문에서는 이중 채널 마이크로폰 어레이 상황에서 언더디터민드 (underdetermined) 하고 합성곱 형식으로 섞여진 신호의 혼합계수 (mixing parameter)를 추정하는 새로운 방법을 제안한다. 최소제곱법 원리를 이용하여 혼합계수들을 추정하는 방법이 소개되며, 분리된 신호는 마이크로폰에서의 신호 형상 (signal image) 레벨로 구해진다. 이 결과, 일반적으로 블라인드 음원분리 기술에서 맞닥뜨리는 스케일링 모호성 (scaling ambiguity)이 없어지게 된다. 제안한 방법은 최소제곱법을 기반을 두며, 일반적으로 블라인드 음원 분리 기술에서 맞닥뜨리는 스케일링 모호성 (scaling ambiguity)를 없앤다. 제안한 방법의 성능은 학계에 공개된 SiSEC 2008 데이터셑을 이용해 측정되었으며, 다양한 종류의 신호 대 잡음비를 측정하고, 그 측정값을 같은 분야의 최신 기술들과 비교함으로써 그 타당성을 입증하였다. Blind source separation for the cocktail-party problem has long been a challenge in Artificial Intelligence (AI) for military applications. The cocktail-party problem states that an intelligent machine cannot locate and listen to the target speaker"s voice when it is surrounded by other sound sources such as in a cocktail party. This paper proposes a novel method to estimate mixing parameters of underdetermined and convolutive mixture of speech sources given a dual-channel microphone array. In the proposed method, the optimal estimate of mixing parameters and the source image is obtained using the least-squares principle. As a result, the scaling ambiguity, which is common in conventional blind source separation methods, is alleviated. Performance evaluation of the proposed method is conducted with a public dataset, SiSEC 2008, and experimental results show the present method"s validity in terms of various SNR measures compared to other state-of-the-art techniques in the field.

USE OF ONLINE FEATURES FOR ONLINE COMPLAINT: IMPLICATIONS ON THE WELL-BEING OF CONSUMERS AND FIRMS

Yean Shan Beh,Laszlo Sajtos 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

It is a fact that the present online technologies have empowered consumers not only to share their positive service experiences they have had with a firm on the Internet, but also to express their negative views online via multiple platforms by using varied online communication features (OCFs) (e.g. status updates, comments, chats, reviews, and feedback forms). With that, this study employed the concept of online features affordances, such as response expectation, identifiability (of complainants), and content visibility, based on a novel conceptualization through the lens of uses and gratifications (U&G) theory from a varied perspective. Hence, by modelling consumers’ motivation to complain about brand via online in conjunction with the selected OCF affordances, this study investigated their joint impact on consumers’ emotions and intentions towards the defaulting firm upon making an online complaint. The data were analysed by using correspondence analysis and structural equation modelling approaches. As a result, this study revealed that consumers’ motivation to complain and their interactions with affordances (but not the affordances themselves) exemplify a significant effect upon influencing the intention towards the (defaulting) firm after disclosing a negative service incident. In particular, content visibility and response expectation appear to display an impact on redress-seeking and egoistic complainants, respectively. These findings, hence, provide relevant insights for firms to manage their complaint channels and to address online customer feedback in a more effective manner for mutual benefits. Furthermore, this study happens to be the first of its kind to weigh in OCFs as the concerned media and further proposes a design-based affordance view of OCFs in explaining their influence on both consumers and brands.

State Legitimacy and Implementation of a Public policy in Malaysia

( Loo See Beh ) 한국정책학회 2011 International Journal of Policy Studies Vol.2 No.1

The economics of developing countries has been marked by inefficient public investment and misguided government interventions that have resulted in many pervasive failures which is mostly due to government`s inability to align their efforts with their country`s resource base and level of development. History revealed these to be characterized by increasing politicization and monopolization of economic advantages with state legitimacy and capacity. When used in response to flawed decision-making process, political inclusion adversely affect government performance and democratization that undermines accountability. Policy formulation in practice only includes members of a specific policy subsystem and politicization tend to promote the continuation of existing practices which may not anchor in the requisite endowments that can help developing-countries governments such as Malaysia in supporting new paradigms of competition and success in tackling the challenges inherent in the creation of new competitive policies and industries. This paper illustrates the umbrella policy which encompasses other policies and practices of the state and in factoring fair dimension of distribution across the society.

The Politics of Governance: Ethical Practices in Public Administration in Malaysia

( Loo See Beh ) 고려대학교 정부학연구소 2007 정부학연구 Vol.13 No.4