• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.1
• /
• pp.72-79
• /
• 1998

Journal of the Korean Society of Clothing and Textiles Vol. 22, No. 1 (1998) p. 72∼79 The purpose of this study was to investigate the effects of geometrical structure and fiber type on the water vapor transport properties of nonwoven batting materials. Two types of fiber were used such as polyester and wool. Correlation between physical properties of nonwovens and water vapor transport rate was analyzed by Pearson Correlation. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltots chloride method respectively. The results were as follows: 1) In geometrical structure, thickness of nonwovens was effected on absorption and evaporation rate and air permeability was more influencing factor on water vapor transport rate than porosity. There were no decreasing of water vapor transport rate in hydrophilic fiber at high relative humudity. 2) The hydrophilicity of fiber affected steady and dynamic state water vapor permeabilities and wool nonwoven showed higher water vapor transport rate than polyester at high relative humidity. 3) Thickness showed higher correlation coefficient with water vapor transport rate than other physical properties of nonwovens.

• Journal of Advanced Navigation Technology
• /
• v.28 no.2
• /
• pp.163-171
• /
• 2024

In the existing air traffic management (ATM) system, various types of safety alert features are provided based on trajectory data to ensure the safety of aircraft operations, along with aircraft position and detailed flight information. The urban air traffic management (UATM) system for urban air mobility (UAM) should also provide safety alert features to ensure the safety of UAM operations. Considering the operational environment of UAM, it is necessary that the safety alert features provided at least match or exceed those available in the existing ATM system. This study aims to present the safety alert features of the new UATM system that differ from those provided by the existing ATM system before introduction and commercialization of UAM. The study was conducted focusing on the safety alert features that should be provided in the event of a deviation from the UAM's path, and the establishment of the safety alert features was carried out in two parts: approach path monitor (APM), which is applied during the approach phase, and route adherence monitoring (RAM), which is applied during the cruise phase.

• Journal of Environmental Science International
• /
• v.23 no.11
• /
• pp.1889-1907
• /
• 2014

The characteristics of meteorological conditions related to changes in atmospheric environment on Jeju Island were investigated during recent years (2010-2012). This analysis was performed using the hourly observed data of meteorological variables (air temperature, wind speed and direction) and air pollutants ($O_3$, $PM_{10}$, $SO_2$, $NO_2$, and CO). Out of 5 pollutants, $O_3$ and $PM_{10}$ concentrations have frequently exceeded national environmental standards in the study area during the study period, with relatively higher concentrations than the others. The concentrations of $O_3$ and $PM_{10}$ in 2010 and 2011 were somewhat higher than those in 2012, and their highest concentrations were mostly observed in spring followed by fall. Nighttime $O_3$ concentrations (with relatively high concentration levels) were almost similar to its daytime concentrations, due to less $O_3$ titration by very low NO concentrations in the target area and in part to $O_3$ increase resulting from atmospheric transport processes. The transport effect related to the concentration variations of $O_3$ and $PM_{10}$ was also clarified in correlation between these pollutants and meteorological variables, e.g. the high exceedance frequency of concentration criteria with strong wind speed and the high concentrations with the westerly/northwesterly winds (e.g., transport from the polluted regions of China). The overall results of this study suggest that the changes in atmospheric environment in the study area were likely to be caused by the transport effect (horizontal and vertical) due to the meteorological conditions rather than the contribution of local emission sources.

• Journal of Korean Society for Atmospheric Environment
• /
• v.17 no.6
• /
• pp.451-461
• /
• 2001

Backward trajectories were calculated from five urban areas in Korea in 1999 in order to assess the effects of long-range transport on the air quality variations on an annual basis. The five areas selected were Seoul, Mokpo, Cheju, Pohang, and Kangnung, which are evenly distributed along the shoreline in Korea. Meteorological fields used in the work were prepared by the Korea Meteorological Administration using the RDAPS(Regional Data Assimilation and Prediction System) with grid spacing of 40 km and 12-h intervals(0000 and 1200 UTC). Upwind regions around the Korean Peninsula were divided into five sectors including the region to the northeast(I), northern China (II), southern China(III), the northwestern Pacific(IV), and Japan(V). The influence of air flow from these sectors on the variations of carbon monoxide concentrations in the selected areas was investigated. The results showed that the influences of Sectors II and III were persistent although some influences of adjacent sectors were observed according to the location of the areas. In general, the concentration of carbon monoxide tended to go up under the influence of Sectors II and III but tended to go down under the influence of Sector I. However, the influences of other sectors were rather mixed. The importance of the long-range transport was examined when the whole country was uniformly influenced by Sectors II and III with strong synoptic winds. The effects of long-range transport were large in Mokpo and Cheju, close to Sectors II and III, where the local emissions were considered small. The effects of local emissions were significant in Pohang and Seoul; such effect was more distinct in Pohang located farther from Sectors II and III.

• The Korean Journal of Air & Space Law and Policy
• /
• v.19 no.2
• /
• pp.9-53
• /
• 2004

This paper described the contents of theme entitled "Domestic Legislative Problems on the Civil Liability of Air Carrier in Korea" including the current example of fourteen countries' legislation ((1) Great Britain, (2) United States of America, (3) Canada, (4)European Union), (5) Germany, (6) France, (7) Italy, (8) Spain, (9) Swiss, (10) Australia, (11) Japan, (12) People's Republic of China, (13) Taiwan, (14) North Korea) relating to the aviation law or air transport law. Though the Korean and Japanese aviation act has provided only the public items such as (1) registration of aircraft, (2) persons engaged in aviation, (3) operation of aircraft, (4) aviation facilities including airport, (5) air transport business, (6) investigate of aircraft accidents etc., but they could not regulated the private items such as the legal relations of the air transport contract (1) air passenger ticket, (2) air luggage ticket, (3) airway bill, (4) liability of air carrier, (5) amount of compensation for damage caused by aircraft accidents, (6)jurisdiction, (7) arbitration, (8) limitation of action, (9) combined carriage, (10) carriage by air performed by an actual carrier other than contracting carrier, damage caused by aircraft to the third parties etc. in their aviation act until now. In order to solve speedily the legal problems on the limitation of air carrier's liability and long law suit and disputes between wrongdoers and survivors etc, it is necessary and desirable for us to enact a new "Draft for the Air Transport Act" including the abovementioned private items. I would like to propose personally and strongly the legislation of "Draft for the Air Transport Act" in Korea in emphasizing the importance of ensuring protection of the interests of consumers air passengers and shippers in carriage by air and the need for equitable compensation between air carriers and survivors caused by the aircraft accidents such as the German Air Transport Act (Luftverkerhrsgesetz).

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.77
• /
• pp.145-168
• /
• 2018

The purpose of this paper is to introduce the limitation of liabilities of multimodal transport operators(MTO) in Korea. Also, this paper reviews the revised draft of Korean Commercial Code in 2015. This paper analyzes Korean multimodal transport systemand the limitation of liabilities of MTO by analyzing articles, regulations and practices of Korean Commercial Code and it's the draft in 2015. The paper, also, studies multimodal transport rules by comparing specifically international treaty, rules, or practices. In Korea, Article 816 of Commercial Code treats multimodal transportation adopting the network liability regime. The Article describes only the case of the multimodal transportation where the maritime carriage is engaged. Korea proposed the draft of multimodal transport regulation of Commercial Code in 2015 because present law could not apply for the multimodal transportation involved in the air or land carriage. This paper support the draft of Korean Commercial Code in 2015 because it is necessary to make a predictable legal system of multimodal transport and the limitation of liability reflecting practices or customs.

• Journal of Korean Society of Transportation
• /
• v.33 no.2
• /
• pp.214-222
• /
• 2015

Jeju International Airport has become the most delayed airport in Korea, due to increased demand in air passengers and unexpected local weather condition. Observing the demands continuously grow for a decade, the airport is expected to be saturated in the near future. As a part of effort to prepare effective and timely measure for this expected situation, airport planners seeks the annual runway capacity, i.e., the appropriate number of flight operations in a given year with tolerable delay. In practice, the FAA formula is frequently adopted for the capacity estimation. The method, however, has intrinsic issues: 1) the hourly capacity imbedded in the formula is not clearly defined and thus the estimated value is vulnerable to be subjective judgement, and 2) the formula doesn't consider aircraft delay resulted from runway congestion. In this paper, we explain a novel method for estimating the daily runway capacity and then converting to the annual capacity taking into account the aircraft delay. In this paper, average delay of aircraft was measured using microscopic air traffic simulation model. Daily capacity of the runways were analyzed based on the simulation outputs and the method to assess the yearly capacity is introduced. Using a microscopic simulation model named TAAM, we measure the average aircraft delay at various levels of flight demand, and then estimate the practical daily runway capacity. The estimated daily and annual runway capacities of Jeju airport are about 460 operations a day which is equal to 169,000 operations year. The paper discusses how to verify the simulation model, and also suggests potential enhancement of the method.

• Particle and aerosol research
• /
• v.15 no.3
• /
• pp.91-104
• /
• 2019

In this study, hourly measurements of $PM_{2.5}$ and its major chemical constituents such as organic and elemental carbon (OC and EC), and ionic species were made between January 15 and February 10, 2018 at the air pollution intensive monitering station in Gwangju. In addition, 24-hr integrated $PM_{2.5}$ samples were collected at the same site and analyzed for OC, EC, water-soluble OC (WSOC), humic-like substance (HULIS), and ionic species. Over the whole study period, the organic aerosols (=$1.6{\times}OC$) and $NO_3{^-}$ concentrations contributed 26.6% and 21.0% to $PM_{2.5}$, respectively. OC and EC concentrations were mainly attributed to traffic emissions with some contribution from biomass burning emissions. Moreover, strong correlations of OC with WSOC, HULIS, and $NO_3{^-}$ suggest that some of the organic aerosols were likely formed through atmospheric oxidation processes of hydrocarbon compounds from traffic emissions. For the period between January 18 and 22 when $PM_{2.5}$ pollution episode occurred, concentrations of three secondary ionic species ($=SO{_4}^{2-}+NO_3{^-}+NH_4{^+}$) and organic matter contributed on average 50.8 and 20.1% of $PM_{2.5}$, respectively, with the highest contribution from $NO_3{^-}$. Synoptic charts, air mass backward trajectories, and local meteorological conditions supported that high $PM_{2.5}$ pollution was resulted from long-range transport of haze particles lingering over northeastern China, accumulation of local emissions, and local production of secondary aerosols. During the $PM_{2.5}$ pollution episode, enhanced $SO{_4}^{2-}$ was more due to the long-range transport of aerosol particles from China rather than local secondary production from $SO_2$. Increasing rate in $NO_3{^-}$ was substantially greater than $NO_2$ and $SO{_4}^{2-}$ increasing rates, suggesting that the increased concentration of $NO_3{^-}$ during the pollution episode was attributed to enhanced formation of local $NO_3{^-}$ through heterogenous reactions of $NO_2$, rather than impact by long-range transportation from China.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2007.10a
• /
• pp.405-406
• /
• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2008.10a
• /
• pp.486-488
• /
• 2008