• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.4
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• pp.58-75
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• 2005

본 연구는 국적항공사를 포함하여 지난 1998${\sim}$2001년까지 세계 주요 항공사들의 생산성의 변화 추이가 어떻게 전개되었고, 어떤 요인에 의해 영향을 받았는지를 분석하였다. 특히, 1997년 금융위기 이후 생산성의 변화에 주안점을 두었다. 추정결과, 우선 세계 주요 항공사들은 1998${\sim}$2001년 기간 동안 약 0.3%의 생산성 하락을 기록하였고, 이러한 생산성의 변화는 생산 프론티어에 비해 0.9% 악화된 반면, 산출물을 생산하는 기술 수준은 0.6% 확대된 것으로 분석되었다. 다음으로, 항공사의 '유상톤키로미터' 기준에 의한 규모별 생산성 증가율은 소형규모(group1)와 대형규모(group6)에 속한 항공사들에서 각각 3.5%, 2.1% 하락한 것으로 나타났다. 반면, 중형사들은 생산성의 증가가 이루어진 것으로 제시되었다. 또한, 기간별로는 1997년 금융위기 이후 1998년과 1999년은 각각 1.5%, 0.2%의 생산성 하락을 보였다가, 2000년은 1.7% 생산성이 다소 향상되었으며, 2001년 다시 1.2%의 생산성 하락을 보이고 있다. 마지막으로 항공사별로는 동 기간 동안 아시아지역 항공사들(AAR, SIA, ANA 등)은 생산상 향상을 가져온 반면, 미국 항공사들(UAL, AAL 등)은 생산성 하락을 가져온 것을 알 수 있다. 국적항공사의 경우에는 KAL은 1998${\sim}$1999년 기간 동안은 생산성 하락을 가져왔으나, 2000${\sim}$2001년은 큰 폭의 생산성 향상을 가져왔다. AAR은 1998년 생산성 하락이 이루어진 이후 1999년부터는 높은 생산성 향상이 이루어졌다.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.287-296
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• 2017

Although emission regulations have been gradually strengthened in the past decade, the road transport section remains the most important source of NOx emission in air pollution. One reason is that there has been an increase in the proportion of diesel vehicles and in the volume of traffic. In addition, the certification procedure for standard emission limit does not sufficiently reflect real traffic condition and various driving patterns. Therefore, the European Commission(EC) has recently come up with the RDE-LDV(Real driving emissions-light duty vehicle) regulations, and the Ministry of Environment in Korea has been conducting research on evaluating RDE-LDV with PEMS(Portable Emission Measurement Systems). According to the trip requirements of the 2nd RDE package announced by the EC, the objectives of the present study include the development of Korean RDE routes to reflect domestic traffic and road conditions. Based on the results, both RDE routes are in correct compliance with RDE-LDV regulations, including trip requirements and trip dynamics. KOR-NIER Route 1, in particular, has a higher driving load in rural driving with regard to excessive gradient of elevation compared to KOR-NIER Route 2, including relatively plane rural driving.

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.14-22
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• 2012

This paper is focused on the comprehensive and detailed interpretation for the chemical transformation of individual Asian dust (hereafter called "AD") particles during long-range transport from source regions to receptor area. A multi-stage particle sampler was operated at a ground-based site in Taean, Korea directly exposed to the outflow of air masses from China during AD period in April 2003. Both quantitative and qualitative analyses for size-classified individual particles were carried out by a microbeam X-ray fluorescence (XRF) method and a microbeam Particle Induced X-ray Emission (micro-PIXE), respectively. Among major characteristic elements, the elemental masses of soil derived components, sulfur, and chloride varied as a function of particle size showing the monomodal maximum with a steeply increasing at 3.3-4.7 ${\mu}m$ particle size. Although the details on chemical composition of AD particle collected on a straight line from source area to our ground-based site are needed, a large amount of Cl coexisted in and/or on AD particles suggests that AD particles collected in the present study might be actively engaged in chemical transformation by sea-salt and other Cl containing pollutants emitted from the China's domestic sources. Through the statistical analyses it was possible to classify individual AD particles into six distinct groups. The internally mixed AD particles with Cl, which has various sources (e.g., sea-salt, coal combustion origin HCl, gaseous HCl derived from the adsorption of acids to sea-salt, and Cl containing man-made particles) were thoroughly fractionated by the elemental spectra drivened by the double detector system of micro-PIXE.

• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.189-197
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• 2010

An orchestrated attempt was made to analyze samples of bulk and individual particulate matters (PM) collected at the Gosan ground-based station on the west coast of Jeju, Korea. A two-stage filter pack sampler was operated to collect particles in both large (> $1.2\;{\mu}m$) and small size fractions (< $1.2\;{\mu}m$) between the Asian dust (hereafter called "AD") storm event and non-Asian dust period. Elemental components in bulk and individual particles were determined by PIXE and synchrotron XRF analysis systems, respectively. To assess the transport pathways of air parcels and to determine the spatial distribution of PM, the backward trajectories of the Meteorological Data Explorer (Center for Global Environmental Research, 2010) and the NOAA's HYSPLIT dispersion-trajectory models were applied. In line with general expectations, Si and other crustal elements in large size particles showed considerably higher mass loading on AD days in comparison with non-AD days. Computation of the crustal enrichment factors [(Z/Si)$_{particle}$/(Z/Si)$_{desert}$ sand] of elements in large size particles (> $1.2\;{\mu}m$) allowed us to estimate the source profile and chemical aging of AD particles as well as to classify the soil-origin elements. On the basis of a single particle analysis, individual AD particles are classified into three distinct groups (neutralized mineral particles, S-rich mineral particles, and imperfectly neutralized particles).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.900-907
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• 2009

In this research, railway transportation by means of the characteristics of tourism in the selection of railroad tourism and to clarify the difference in IPA is a primary purpose of this research. In addition, the train travel experience would like to clarify the difference in the importance and performance. This research fellows the indication points. First, by means of transportation to select train tourism product is the difference in the importance and performance in the 25 items. Second, the urgent needs to improve part 'Concentrate Here' side of the train, the temperature of the reasonable air-conditioning, and the appropriate means of transport links to the information service has been identified.'Low Priority' side of the entry tourist train operation of the frequency and interval, a total of 26 items, including the efforts of more than the current level of commitment was expected to be unnecessary. Third, according to the experience of sightseeing train railway transportation as a means to help train tourism product selection was the difference in the importance and performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.449-454
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• 2010

In this paper, flow characteristics of R600a in an adiabatic capillary tube were investigated employing the homogeneous flow model. The model is based on fundamental equations of mass, energy and momentum which are solved simultaneously. Two friction factors(Churchill) and viscosity(McAdams) are comparatively used to investigate the flow characteristics. Thermodynamic and transport properties of R600a are calculated employing EES property code. Flow characteristics analysis of R600a in an adiabatic capillary tube is presented to offer the basic design data for the operating parameters. The operating parameters considered in this study include condensation temperature, evaporation temperature, subcooling degree and inner diameter tube of the adiabatic capillary tube. The main results were summarized as follows: condensation and evaporation temperature, inlet subcooling degree and inner diameter tube of an adiabatic capillary tube using R600a have an effect on length of an adiabatic capillary tube. The length of an adiabatic capillary tube using R600a is expressed to the correlation shown in Eq. (15).

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4815-4821
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• 2014

Background: This study aimed to examine the relationship between respiratory health of Malaysian adolescents with secondhand smoke (SHS) exposure and smoke-free legislation (SFL) implementation. Materials and Methods: A total of 898 students from 21 schools across comprehensive- and partial-SFL states were recruited. SHS exposures and respiratory symptoms were assessed via questionnaire. Prenatal and postnatal SHS exposure information was obtained from parental-completed questionnaire. Results: The prevalence of respiratory symptoms was: 11.9% ever wheeze, 5.6% current wheeze, 22.3% exercise-induced wheeze, 12.4% nocturnal cough, and 13.1% self-reported asthma. SHS exposure was most frequently reported in restaurants. Hierarchical logistic regression indicates living in a comprehensive-SFL state was not associated with a lower risk of reporting asthma symptoms. SHS exposure in public transport was linked to increased risk for wheeze (Adjusted Odds Ratio (AOR) 16.6; 95%confidence interval (CI), 2.69-101.7) and current wheezing (AOR 24.6; 95%CI, 3.53-171.8). Conclusions: Adolescents continue to be exposed to SHS in a range of public venues in both comprehensive- and partial-SFL states. Respiratory symptoms are common among those reporting SHS exposure on public transportation. Non-compliance with SFL appears to be frequent in many venues across Malaysia and enforcement should be given priority in order to reduce exposure.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.124-141
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• 2006

Fiji is referred to as the hub of the South Pacific as it lies on the major sea and air transport routes in the region. Tourism, the fastest growing industry within the global economy, is already well established within the country. This paper aims to explore the characteristics of ecotourism in Fiji Islands as a foreign area study. To achieve the objectives, this research carried out a literature review before taking several field surveys in Fiji Islands. Research areas are Raintree Lodge in Suva, Kula Ecopark near Sigatoka, Sigatoka Sand Dunes National Park, Nalesutale Fijian indigenous village near Nadi. Most of all facilities and ecotour programs are developed for environmental, economical and educational effects. The case studies of Fiji present a good model of how to succeed in ecotourism and conservation management to Korea. In addition, this research will provide effective regional policies for the environmental friendly tourism in Korea.

• Asian Journal of Atmospheric Environment
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• v.9 no.4
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• pp.259-271
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• 2015

This study conducted analyses on biogenic volatile organic compounds (BVOC) emission sources contributing to urban ozone ($O_3$) concentration in Osaka Prefecture, Japan in summer 2010 by using the Weather Research and Forecasting model (WRF) version 3.5.1 and the Community Multiscale Air Quality model (CMAQ) version 5.0.1. This prefecture is characterized by highly urbanized area with small forest area. The contributions of source regions surrounding Osaka were estimated by comparing the baseline case and zero-out cases for BVOC emissions from each source region. The zero-out emission runs showed that the BVOC emissions substantially contributed to urban $O_3$ concentration in Osaka (10.3 ppb: 15.9% of mean daily maximum 1-h $O_3$ concentration) with day-by-day variations of contributing source regions, which were qualitatively explained by backward trajectory analyses. Although $O_3$ concentrations were especially high on 23 July and 2 August 2010, the contribution of BVOC on 23 July (35.4 ppb: 25.6% of daily maximum $O_3$) was much larger than that on 2 August (20.9 ppb: 14.2% of daily maximum $O_3$). To investigate this difference, additional zero-out cases for anthropogenic VOC (AVOC) emissions from Osaka and for VOC emissions on the target days were performed. On 23 July, the urban $O_3$ concentration in Osaka was dominantly increased by the transport from the northwestern region outside Osaka with large contribution of $O_3$ that was produced through BVOC reactions by the day before and was retained over the nocturnal boundary layer. On 2 August, the concentration was dominantly increased by the local photochemical production inside Osaka under weak wind condition with the particularly large contribution of AVOC emitted from Osaka on the day.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.5
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• pp.435-444
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• 2017

In this study, we investigated the effect of aerosol feedback on $PM_{10}$ simulation using a two-way coupled air quality model (WRF-CMAQ). $PM_{10}$ concentration over Korea in January 2014 was simulated, and the aerosol feedback effect on the simulated solar radiation was intensively examined. Two $PM_{10}$ simulations were conducted using the WRF-CMAQ model with (FB) and without(NFB) the aerosol feedback option. We find that the simulated solar radiation in the west part of Korea decreased by up to $-80MJ/m^2$ due to the aerosol feedback effect. The feedback effect was significant in the west part of Korea, showing high $PM_{10}$ estimates due to dense emissions and its long-range transport from China. The aerosol feedback effect contributed to the decreased rRMSE(relative Root Mean Square Error) for solar radiation (47.58% to 30.75%). Aerosol feedback effect on the simulated solar radiation was mainly affected by concentration of $PM_{10}$. Moreover, FB better matched the observed solar radiation and $PM_{10}$ concentration than NFB, implying that taking into account the aerosol direct effects resulted in the improved modeling performance. These results indicate that aerosol feedback effects can play an important role in the simulation of solar radiation over Korean Peninsula.