The origin, evolution, and application of the megapolitan area concept

Robert E. Lang,임재원,Karen A. Danielsen 서울시립대학교 도시과학연구원 2020 도시과학국제저널 Vol.24 No.1

The article explores the origin and evolution of the ‘megapolitan concept', the idea of a super-sized region that began in 1961 in Jean Gottmann's ‘megalopolis,' which he developed to explain large-scale urbanization in the Northeastern U.S. Jerome Picard, a researcher at the Urban Land Institute took up the megalopolis idea in 1967 and applied it to the entire U.S. and projected large-scale urban growth to 2000. The Regional Plan Association (RPA) also applied the megalopolis concept to The Second Regional Plan for New York in 1968. Lang in 2000s, then working with his colleagues at Virginia Tech developed the megapolitan concept and definition-in part to differential the concept from work being done by the University of Pennsylvania for RPA. Lang defined ‘megapolitan clusters’ as multiple megapolitan areas that are networked either by commuting, logistics, or dense air links, but where there is no more than three times the distance used to define a Megapolitan Area between anchor metropolitan areas at their furthest distance. The recent evolution of megapolitan area and megapolitan cluster concepts by Lang and the colleagues is applied to a series of projects, including ‘Sun Corridor’ in 2006 (Phoenix-Tucson) and the Southwest Triangle (SoCal-Sun Corridor-Las Vegas) in 2014. The article ends with the future application of megapolitan area concept in the rapidly growing Southwest Triangle megapolitan cluster.

A Robust Method for Speech Replay Attack Detection

( Lang Lin ),( Rangding Wang ),( Diqun Yan ),( Li Dong ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.1

Spoofing attacks, especially replay attacks, pose great security challenges to automatic speaker verification (ASV) systems. Current works on replay attacks detection primarily focused on either developing new features or improving classifier performance, ignoring the effects of feature variability, e.g., the channel variability. In this paper, we first establish a mathematical model for replay speech and introduce a method for eliminating the negative interference of the channel. Then a novel feature is proposed to detect the replay attacks. To further boost the detection performance, four post-processing methods using normalization techniques are investigated. We evaluate our proposed method on the ASVspoof 2017 dataset. The experimental results show that our approach outperforms the competing methods in terms of detection accuracy. More interestingly, we find that the proposed normalization strategy could also improve the performance of the existing algorithms.

[⁷⁶Br]BMK-I-152, a non-peptide analogue for PET imaging of corticotropin-releasing hormone type 1 receptor (CRHR1)

Lang, L.,Ma, Y.,Kim, B. M.,Jagoda, E. M.,Rice, K. C.,Szajek, L. P.,Contoreggi, C.,Gold, P. W.,Chrousos, G. P.,Eckelman, W. C.,Kiesewetter, D. O. John Wiley Sons, Ltd. 2009 Journal of labelled compounds & radiopharmaceutica Vol.52 No.9

<P>The study of corticotropin-releasing hormone is of significant interest in mental health. We have developed a radiobromination procedure for the preparation of [<SUP>76</SUP>Br]BMK-I-152, a high-affinity corticotropin-releasing hormone type 1 receptor antagonist. The radiobromination procedure resulted in the formation of two radiobrominated products from the same trialkyltin precursor. Utilizing the results of several reaction conditions and the chromatographic and mass spectral data obtained from Waters Acquity and Q-TOF, we determined that both 3-bromo and 4-bromo isomers could be obtained. The authentic sample of the 3-bromo isomer was prepared to confirm the identity of a previously unknown radioactive side product; affinity assays revealed that the 4-bromo isomer had ∼70 times higher affinity than that of the 3-bromo compound. By manipulation of reaction conditions, the individual products could be selected. Under no-carrier-added conditions at room temperature in aqueous acetonitrile, the major radioactive product (>80%) was identified as the 3-[<SUP>76</SUP>Br]bromo-4-tributylstannyl analogue of BMK-I-152. The 4-[<SUP>76</SUP>Br]bromo isomer accounted for less than 1% of the total activity. The 3-[<SUP>76</SUP>Br]bromo BMK-I-152 could be obtained by treating this intermediate with trifluoroacetic acid to effect removal of the trialkyltin. If the radiobromination was conducted after first evaporating the water from the aqueous ammonium hydroxide solution of [<SUP>76</SUP>Br]bromide, the desired 4-[<SUP>76</SUP>Br]bromo isomer was obtained with a 58% radiochemical yield. Copyright © 2009 John Wiley & Sons, Ltd.</P> <B>Graphic Abstract</B> <P>Radiolabeling of tributyltin precursor yielded two radioactive products. Copyright © 2009 John Wiley & Sons, Ltd. <img src='wiley_img/03624803-2009-52-9-JLCR1616-gra001.gif' alt='wiley_img/03624803-2009-52-9-JLCR1616-gra001'> </P>

Opioid-induced constipation: a narrative review of therapeutic options in clinical management

Lang-Illievich, Kordula,Bornemann-Cimenti, Helmar The Korean Pain Society 2019 The Korean Journal of Pain Vol.32 No.2

Pain therapy often entails gastrointestinal adverse events. While opioids are effective drugs for pain relief, the incidence of opioid-induced constipation (OIC) varies greatly from 15% to as high as 81%. This can lead to a significant impairment in quality of life, often resulting in discontinuation of opioid therapy. In this regard, a good doctor-patient relationship is especially pivotal when initiating opioid therapy. In addition to a detailed history of bowel habits, patient education regarding the possible gastrointestinal side effects of the drugs is crucial. In addition, the bowel function must be regularly evaluated for the entire duration of treatment with opioids. Furthermore, if the patient has preexisting constipation that is well under control, continuation of that treatment is important. In the absence of such history, general recommendations should include sufficient fluid intake, physical activity, and regular intake of dietary fiber. In patients of OIC with ongoing opioid therapy, the necessity of opioid use should be critically reevaluated in terms of an with acceptable quality of life, particularly in cases of non-cancer pain. If opioids must be continued, lowering the dose may help, as well as changing the type of opioid. If these measures do not suffice, the next step for persistent OIC is the administration of laxatives. If these are ineffective as well, treatment with peripherally active ${\mu}$-opioid receptor antagonists should be considered. Enemas and irrigation are emergency measures, often used as a last resort.

Learning Multiple-Gait Quadrupedal Locomotion via Hierarchical Reinforcement Learning

Lang Wei,Yunxiang Li,Yunfei Ai,Yuze Wu,Hao Xu,Wei Wang,Guoming Hu 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.9

Over long periods of evolution, legged animals have developed the capability to use a variety of gaits to move efficiently and flexibly at different speeds. To enable quadruped robots to acquire this ability, this study proposes a two-stage training hierarchical framework that can have quadruped robots generate energy-efficient multiple-gait locomotion, consisting of a gait selection policy module and a react controller module. The parameters of both modules are optimized using reinforcement learning. The experimental results in the simulation demonstrate that the proposed method can generate energy-efficient multiple-gait quadrupedal locomotion compared to previous methods. To validate the robustness and effectiveness of the method, we constructed a closed-chain quadruped robot and deployed the controller trained by the method to the robot. The experimental results in the real world suggest that the controller can enable the robot to move stably and efficiently in different gaits. The main contribution of this paper is that the authors propose a novel hierarchical framework, which makes quadruped robots use an optimal gait at a specific speed and smoothly switch to another one after getting a different speed command. These behaviors are automatically produced through simulation training, eliminating the need for the tedious work of designing gaits and modulating controllers. Experimental results showcase that the proposed method has significant advantages compared to previous methods.

N-Step Sliding Recursion Formula of Variance and Its Implementation

Lang Yu,Gang He,Ahmad Khwaja Mutahir 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.4

The degree of dispersion of a random variable can be described by the variance, which reflects the distance of the random variable from its mean. However, the time complexity of the traditional variance calculation algorithm is O(n), which results from full calculation of all samples. When the number of samples increases oron the occasion of high speed signal processing, algorithms with O(n) time complexity will cost huge amount of time and that may results in performance degradation of the whole system. A novel multistep recursive algorithm for variance calculation of the timevarying data series with O(1) time complexity (constant time) is proposed in this paper. Numerical simulation and experiments of the algorithm is presented and the results demonstrate that the proposed multistep recursive algorithm can effectively decrease computing time and hence significantly improve the variance calculation efficiency for timevarying data, which demonstrates the potential value for timeconsumption data analysis or high speed signal processing.

An algorithm for labia minora reduction based on a review of anatomical, configurational, and individual considerations

Lange Maurits DJ,Hage J. Joris,Karim Refaat B,Amant Frederic 대한성형외과학회 2023 Archives of Plastic Surgery Vol.50 No.1

A variety of labiaplasty techniques have been introduced to date, but no single technique will offer the optimal solution for every patient. Rather, the technique should be chosen based on anatomical, configurational, and technical considerations, as well as on patients’ personal preferences regarded maintenance of the labial rim, maintenance of labial sensitivity, and prevention of iatrogenic thickening of the labium. We reviewed, defined, and assessed labial configurational variety, neurovascular supply, reduction techniques, and patient’s preferences as the considerations relevant to the choice of labiaplasty technique. Based on this review, an algorithm was constructed that leads to a choice of reduction technique through five decisions to be made regarding (1) resection or (partial) retention of the labial free rim, (2) the measure of required labial width reduction, (3) labial vascular status, (4) prevention of iatrogenic labial thickening, and (5) preservation of labial sensibility. The choice of techniques includes edge trimming, central spindle form de-epithelialization or full thickness resection, and three modifications of the wedge resection or de-epithelialization technique. These three modifications comprised a modified anterior resection or de-epithelialization combined with posterior flap transposition, a custom flask resection or de-epithelialization, and a modified posterior wedge resection or de-epithelialization combined with anterior flap transposition. Use of the five decisional steps and the inclusion of modifications of all three conventional reduction techniques offer an improved algorithm for the choice of labioplasty technique.

Interpretations for China’s Weak Role in Managing the DPRK Nuclear Crisis

LANG KUN,이철호 21세기정치학회 2019 21세기 정치학회보 Vol.29 No.2

East Asian regional stability requires a peaceful solution to the DPRK nuclear crisis. Even though the ultimate rescue of this issue belongs to the US-DPRK rapprochement, Chin’s role in the DPRK denuclearization process turns out non-significant. This paper aims to interpret the reasons for China’s powerlessness in two dimensions: the Chinese-culture-born ‘all-under-heaven philosophy’ that influences Chinese diplomacy has not been provided China a Western-acceptable international relations theory to deal with the DPRK nuclear crisis; China’s changing strategy toward DPRK reduced the trust from relevant countries, which led to China’s voicelessness. Meanwhile, China’s efforts and contributions to improving the DPRK nuclear issue shouldn’t be ignored. As long as the pivot of the tribute system as a traditional peace management mechanism is ‘a rich China’ rather than ‘a forceful China’, the so-called ‘Chinese School’ should focus the efforts on economic issues that would benefit the relevant countries. In the same context, the stability of Korean peninsula should start from the exchange activities in the ‘low politics’ areas which would consolidate the public support for bilateral ties.

Co‑doped amorphous MoSx for efficient hydrogen evolution reaction in acid condition

Lang Gan,Jincheng Liu,Yanjie Ren,Zhongyi Xiong,Kang Chen 한국탄소학회 2023 Carbon Letters Vol.33 No.5

Amorphous molybdenum sulfide ( MoSx) has been regarded as a promising hydrogen evolution reaction (HER) catalyst due to its mild preparation conditions and low-cost precursor materials. In this work, we report a simple strategy combining the growth of amorphous MoSx on the surface of metal organic frameworks (ZIF-67) and annealing treatment to prepare Co-doped MoSx nanopolyhedrons (denoted as CoMoSx NPs). The CoMoSx NPs exhibit excellent HER activity in acid condition with an overpotential of 188 mV at a current density of 10 mA cm? 2 (η10), and a relatively stable overpotential after 2000 cyclic voltammetry (CV) cycles testing. The excellent HER performance of the CoMoSx NPs can be attributed to the doping of Co element adjust the electronic structure and increase the conductivity of catalyst, and the nanopolyhedrons structure which can expose more active sites for HER electrocatalytic. This study offers a low-cost and simple strategy to prepare high-activity HER catalyst, which holds great promises in developing advanced electrocatalysts for energy storage.

Encoding-based brain-computer interface controlled by non-motor area of rat brain.

Lang, Yiran,Du, Ping,Shin, Hyung-Cheul Jointly published by Science China Press and Sprin 2011 Science China. Life sciences Vol.54 No.9

<P>As the needs of disabled patients are increasingly recognized in society, researchers have begun to use single neuron activity to construct brain-computer interfaces (BCI), designed to facilitate the daily lives of individuals with physical disabilities. BCI systems typically allow users to control computer programs or external devices via signals produced in the motor or pre-motor areas of the brain, rather than producing actual motor movements. However, impairments in these brain areas can hinder the application of BCI. The current paper demonstrates the feasibility of a one-dimensional (1D) machine controlled by rat prefrontal cortex (PFC) neurons using an encoding method. In this novel system, rats are able to quench thirst by varying neuronal firing rate in the PFC to manipulate a water dish that can rotate in 1D. The results revealed that control commands generated by an appropriate firing frequency in rat PFC exhibited performance improvements with practice, indicated by increasing water-drinking duration and frequency. These results demonstrated that it is possible for rats to understand an encoding-based BCI system and control a 1D machine using PFC activity to obtain reward.</P>