The role of seaports in regional employment: evidence from South Korea

<p>The role of seaports in regional employment: evidence from South Korea. <i>Regional Studies</i>. This study examines the seaport’s influence on regional employment in all 16 regions of Korea, including seven metropolitan areas, based on panel data between 2002 and 2013. It expands an economic model of regional unemployment from labour economics and an autoregressive model from econometrics by employing port potentials separately estimated in a Tobit model. The result indicates that port activities significantly reduce regional unemployment rates relative to the national level. The role of population, gross domestic product (GDP) and household income on unemployment rate was highlighted, whilst various determinants of port potentials were investigated about whether they stimulate port potentials.</p

Novel water filtration of saline water in the outermost layer of mangrove roots

The scarcity of fresh water is a global challenge faced at present. Several desalination methods have been suggested to secure fresh water from sea water. However, conventional methods suffer from technical limitations, such as high power consumption, expensive operating costs, and limited system durability. In this study, we examined the feasibility of using halophytes as a novel technology of desalinating high-concentration saline water for long periods. This study investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water, and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses a hierarchical, triple layered pore structure in the epidermis, and most Na+ ions are filtered at the first sublayer of the outermost layer. The high blockage of Na+ ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures, also facilitates Na+ ion filtration. This study provides insights into the mechanism underlying water filtration through halophyte roots and serves as a basis for the development of a novel bio-inspired desalination method.Creative Research Initiative (Diagnosis of Biofluid Flow Phenomena and Biomimic Research) of the Ministry of Science, ICT and Future Planning (MSIP) , National Research Foundation (NRF) of Korea , ICT R&D program of MSIP/IITP (Korea

Visual Function after Primary Posterior Chamber Intraocular Lens Implantation in Pediatric Unilateral Cataract: Stereopsis and Visual Acuity

PURPOSE: To investigate the association between binocular function and vision after cataract removal and primary posterior chamber intraocular lens (PC-IOL) implantation in children with unilateral cataract and to identify visual function differences according cataract type. METHODS: Clinical records of 2- to 6-year-old patients with unilateral cataract removal and primary PC-IOL implantation were reviewed retrospectively. Visual acuity and ocular alignment were measured. Sensory fusion was assessed with the Worth 4-dot test, and stereoacuity with the Titmus stereo test. Cataracts were classified according to cause, lens opacity location, age at onset, and presence of strabismus. Clinical characteristics of patients who obtained good visual function were identified. RESULTS: Forty-seven patients were included. Among 22 (46.8%) with good vision (20/40 or better), only 6 (27.3%) achieved good binocular function (the presence of fusion and 100 seconds of arc or better of stereoacuity). Visual acuity was better in eyes with good binocular function (p=0.002). No other variables were significant for achieving good binocular function. CONCLUSIONS: The removal of unilateral cataract in a visually immature child can result in a combination of good visual acuity and binocular function. Good binocular function is closely related to good visual acuity

Enabling location-aware quality-controlled access in wireless networks

Location-based services (LBSs), such as location-specific contents-providing services, presence services, and E-911 locating services, have recently been drawing much attention in wireless network community. Since LBSs rely on the location information in providing services and enhancing their service quality, we need to devise a framework of directly using the location information to provide a different level of service differentiation and/or fairness for them. In this paper, we investigate how to use location information for QoS provisioning in IEEE 802.11-based Hot Spot networks. Location-based service differentiation is different from existing QoS schemes in that it assigns different priority levels to different locations rather than flows or stations and schedules network resources to support the prioritized service levels. In order to realize such the location-based service differentiation, we introduce the concept of per-location target load to simply represent the desirable rate of traffic imposed to the network, which is dynamically changing due to the number of stations. The load consists of per-location load, which directly quantifies per-location usage of link capacity, and network-wide load, which indirectly calibrates the portion of per-location load contributed to the network-wide traffic. We then propose a feedback framework of provisioning service differentiation and/or fairness according to per-location target load. In the proposed framework, the load information is feedback to traffic senders and used to adjust their sending rate, so that per-location load does not deviate from a given per-location share of wireless link capacity and lays only tolerable traffic on the network in cooperation with other locations. We finally implemented the proposed framework in ns-2 simulator and conducted an extensive set of simulation study so as to evaluate its performance and effectiveness. The simulation results indicate that the proposed framework provides location-based service differentiation and/or fairness in IEEE 802.11 Hot Spot networks, regardless of the number of stations in a location, traffic types, or station mobility. © 2011, Kim et al; licensee Springer.1

Sleeve Lobectomy as an Alternative Procedure to Pneumonectomy for Non-small Cell Lung Cancer

IntroductionThe aim of this study is to compare the outcomes of sleeve lobectomy (SL) and pneumonectomy (PN) and to determine which one is more acceptable standard procedure for patients with non-small cell lung cancer.MethodsFrom 1996 to 2005, 424 patients underwent SL (n = 157) and PN (n = 267) in our institution. Propensity score matching analysis was performed to compare these two groups for mortality, morbidity, survival, recurrence, and postoperative pulmonary function.ResultsIn each group, 105 patients were eligible for analysis. The operative mortality was lower in the SL group (1.0%) than the PN group (8.6%), (p < 0.0001). The morbidity was similar (33.4% versus 29.5%, p = 0.376). The 5-year survival was lower in the PN group (PN, 32.14% versus SL, 58.43%, p = 0.0002). The recurrence pattern (locoregional versus distant) did not differ between two groups (p = 0.180). The mean actual postoperative first second forced expiratory volume in the patients underwent SL was 2.05 ± 0.55 liter, which increased by 7.9% compared with the predicted-postoperative first second forced expiratory volume.ConclusionsOur results showed that the SL can be performed with low operative risk and may offer superior survival and better postoperative pulmonary function compared with the PN in selected patients. If anatomically feasible, a SL must be considered as a favorable alternative to PN in patients with non-small cell lung cancer

Small and Medium Amplitude Oscillatory Shear Rheology of Model Branched Polystyrene (PS) Melts

Linear and nonlinear rheological properties of model comb polystyrenes (PS) with loosely to densely grafted architectures were measured under small and medium amplitude oscillatory shear (SAOS and MAOS) flow. This comb PS set had the same length of backbone and branches but varied in the number of branches from 3 to 120 branches. Linear viscoelastic properties of the comb PS were compared with the hierarchical model predictions. The model underpredicted zero-shear viscosity and backbone plateau modulus of densely branched comb with 60 or 120 branches because the model does not include the effect of side chain crowding. First- and third-harmonic nonlinearities reflected the hierarchy in the relaxation motion of comb structures. Notably, the low-frequency plateau values of first-harmonic MAOS moduli scaled with M$^{-2}$$_{w}$ (total molecular weight), reflecting dynamic tube dilution (DTD) by relaxed branches. Relative intrinsic nonlinearity Q$_{0}$ exhibited the difference between comb and bottlebrush via no low-frequency Q$_{0}$ peak of bottlebrush corresponding to backbone relaxation, which is probably related to the stretched backbone conformation in bottlebrush