• Korean Journal of Ichthyology
• /
• v.34 no.3
• /
• pp.153-159
• /
• 2022

The olfactory organ of a Korean endemic species, Pseudobagrus koreanus, was investigated to describe its morphology and histology and analyze correlation between habitat environment and its ecological habits and characters, using a stereo microscope, a light microscope, and a scanning electron microscope. Its external morphology showed tubular anterior nostril at the tip of the snout and slit posterior nostril at the base of the nasal barbel. The olfactory chamber showed the rosette structure consisting of numerous lamellae radial and parallel to the medium raphe. The olfactory lamella has the sensory epithelium with olfactory receptor nuerons, supporting cells, basal cells, lymphatic cells, plasma cells and the non-sensory epithelium with stratified epithelial cells, mucous cells, lymphatic cells. In particular, 1) 41~43 (n=20) lamellae, 2) lymphatic cells and plasma cells, 3) mucous cells including neutral polysaccharid may be olfactory characteristics relevant to a stagnant or a standing habitat environment, nocturnal habit dependent on olfaction, and taxonomic characters compared at least to other catfish species.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.12 no.3 s.26
• /
• pp.193-199
• /
• 2006

The noise levels on board ship recognized at Europe in the early 1970s and the noise regulations on the ship began to put in a statutory form. After that, in 1982 'International Code on Noise Levels on Board Ships' adopted by IMO and it became a standards to the newly built ship and it remains up to recently. Especially, the ship engine room, which have huge main engine and various kinds of subsidiary machines, is under an extremely loud condition and so the worker who works in it is easy to lose his hearing. Recently, each nation regulates the allowable noise exposure time by law to protect the industrial employee from the occupational hardness of hearing. In our country, the allowable noise exposure time is regulated by the labor. standard law but the international provisions regulated by IMO have been applied in case of the ship engine room. In this paper, the cabin's noise levels of cargo-passenger ships plies south-west coast line were investigated.

• Journal of Advanced Technology Convergence
• /
• v.2 no.3
• /
• pp.17-24
• /
• 2023

I am designing a research paper with the aim of studying hybrid vehicles. Hybrid vehicles, as the next-generation automobiles, feature a combination of internal combustion engines and battery engines, resulting in a revolutionary reduction in fuel consumption and harmful gas emissions compared to conventional vehicles. The electric motor in hybrid cars derives power from a high-voltage battery installed within the vehicle, which is recharged during vehicle motion. In contrast to traditional cars, which often experience energy losses due to idling caused by traffic congestion, hybrid systems optimize efficiency by skillfully managing the interplay between the internal combustion engine and the electric motor. This approach effectively addresses the inherent drawbacks of gasoline or diesel engines.Hybrid cars offer an array of benefits, including improved fuel efficiency, environmental friendliness, cost-effectiveness, and reduced noise emission. Consequently, they are progressively becoming a favored alternative among a growing number of individuals. This research endeavor has the potential to contribute towards curbing environmental pollution and dedicating efforts to future automotive research.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.1
• /
• pp.184-192
• /
• 2022

Valve internal leakage is caused by damage to the internal parts of the valve, resulting in accidents and shutdowns of the piping system. This study investigated the possibility of a real-time leak detection method using the acoustic emission (AE) signal generated from the piping system during the internal leakage of a butterfly valve. Datasets of raw time-domain AE signals were collected and postprocessed for each operation mode of the valve in a systematic manner to develop a data-driven model for the detection and classification of internal leakage, by applying machine learning algorithms. The aim of this study was to determine whether it is possible to treat leak detection as a classification problem by applying two classification algorithms: support vector machine (SVM) and convolutional neural network (CNN). The results showed different performances for the algorithms and datasets used. The SVM-based binary classification models, based on feature extraction of data, achieved an overall accuracy of 83% to 90%, while in the case of a multiple classification model, the accuracy was reduced to 66%. By contrast, the CNN-based classification model achieved an accuracy of 99.85%, which is superior to those of any other models based on the SVM algorithm. The results revealed that the SVM classification model requires effective feature extraction of the AE signals to improve the accuracy of multi-class classification. Moreover, the CNN-based classification can be a promising approach to detect both leakage and valve opening as long as the performance of the processor does not degrade.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.1
• /
• pp.108-115
• /
• 2019

The thermal response of elastomeric insulators used as protection against high-temperature and high-pressure combustion gases varies depending on their composition and thermal environment conditions. In this paper, the thermal response characteristics of elastomeric insulators in different mixing environments were compared. Tests to determine thermal protection performance were carried out using a thermal protection rubber evaluation motor(TPREM), combustion gas velocities of 20 m/s and 100 m/s were tested at a chamber pressure of 1,000 psig. The pressure time curve of the chamber, the temperature time curve of the internal materials, the residual thickness and the thermal destruction depth of the test specimens were obtained. The results showed that the thermal protection performance of elastomeric insulators in different mixing environments was similar.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.4
• /
• pp.987-996
• /
• 2015

According to the recent research results of the Ministry of Environment, the indoor air quality of large general hospitals and university hospitals(58 hospitals) exceeded the maintenance standard. On top of such indoor air quality, it is also desperately required to have the environment-friendly building design and also low carbon green design in accordance with the increase of hospital size and enlarged hospital buildings. Especially, the increase of carbon dioxide, heat, garbage, waste energy, exhaust heat from power plants and sewage heat in each medical center brings up lots of problems to the health of hospital patients and customers. Thus this study aims to convergently develop the green environment-friendly architecture design technology concerning the organic relations between each medical building, and technical development which should be introduced to the low carbon green environment-friendly architecture design based on the characteristics of each medical center in large-scale medical complex.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2002.11a
• /
• pp.108-109
• /
• 2002

The study was carried out to iind out the suitable ventilation system of the broiler house in winter season in Korea. Ammonia (NH$_3$-N) gas concentration (4.2ppm) of the system of pipe air inlet-forced chimney outlet was lower than that of the system of side wall inlet. The growth performance of broilers in the house equiped with pipe air inlet-chimney exhaust was higher than that of other ventilation systmes in which the average daily gain, feed efficiency and heat cost per head in the system of pipe air inlet-forced chimney excretion were 45.6g, 1.71 and 35.4 won per head, respectively. When the lengths of pipe air inlets were compared, the wind speed from the 4 meter-inlet was highest. The temperature of the broiler house equipped with the pipe air inlet system was higher (5.9 ∼ 7.7$^{\circ}C$) than that of the curtains in side wall Inlet system, in which the pipe air inlet system expects the lower heat cost.

• Korean Journal of Ichthyology
• /
• v.30 no.3
• /
• pp.161-166
• /
• 2018

The olfactory organ of Korean endemic fish Microphysogobio yaluensis are described anatomically and histologically, focused on relationship to its habitat and ecology. The paired olfactory organs are located at the dorsal snout, and externally consist of two semicircular nostrils and single nasal flap. They internally have rosette structure with 22 to 24 units of lamellae and the raphe inside the olfactory chamber. The lamella is made up of the sensory and the non-sensory epitheliums. The sensory epithelium has olfactory receptor neurons, supporting cells and basal cells whereas the nonsensory epithelium has stratified epithelial cells, ciliated non-sensory cells and mucous cells with acidic and neutral mucins. These structures might be considered that M. yaluensis has the olfactory organ which corresponds to the high sensitivity for its habitat and ecology, and is usable as a taxonomic key.

• Journal of the Korean Society for Library and Information Science
• /
• v.52 no.1
• /
• pp.313-340
• /
• 2018

The purpose of this study was to design a PCSI model that can be applicable to measurement of library user satisfactions, which can be used in evaluating organizational performance. The National Assembly Library (NAL) was selected as a case to design a PCSI-based model and to test the model by conducting a self-administered survey of 341 internal and external library users. The model was validated to have a satisfactory model fit. Fitting the model, the study confirms that the service qualities of the NAL affect user satisfactions, which in turn affects organizational performances. The PCSI score of the library was 80.4, which can be used as a useful index that can compare the library's performance with other organizations in the similar public domain. Major contributions of this study are two-fold: the PCSI-based model proposed in this study provides a theoretical basis that assesses organizational performance of libraries via user satisfaction; and libraries can utilize the model as a management tool to assess the organizational performance from the user perspective.

• Annual Conference of KIPS
• /
• 2015.04a
• /
• pp.404-405
• /
• 2015

최근 IT기술과 인터넷의 발전으로 시간과 공간에 제한을 두지 않고 업무를 처리해야 하는 상황으로 업무환경이 급격히 변화되고 있다. 특히 기업에서는 외부 네트워크와 정보교환의 필요성이 증가되었고, 구성원들의 잦은 외근, 출장 등 사무실 밖에서 업무를 처리하는 비중이 높아져, 내부뿐만 아니라 외부와의 정보공유를 하는데 있어 안전한 네트워크 구조를 요구하고 있다. 외부에서 효율적이고 안전하게 내부시스템에 접속할 수 있게 사용되는 것이 VPN(가상사설망: Virtual Private Network)으로, 기관 및 기업에서 VPN을 지속적으로 도입하여 운영하고 있다. 하지만 VPN에 인증이 성공되면 다양한 업무시스템에 접근이 용이하기 때문에, 악의적인 사용자로부터 정보유출이 손쉽게 이루어질 수 있다. 따라서 본 연구에서는 사용되고 있는 VPN에 대해 관리가 잘 이루어지는지 확인하는 실태점검 리스트를 제시하고, VPN에 대한 정보유출방지 모니터링을 위해 VPN의 접속로그를 분석하여 정보유출 보안위협행위를 탐지할 수 있는 시나리오를 도출하고자 한다.