• Animal Systematics, Evolution and Diversity
• /
• v.36 no.1
• /
• pp.17-24
• /
• 2020

Doryctinae is a large and heterogeneous group with more than 1,000 described. It is idiobiont ectoparasitoids on the larvae of wood-boring and xylophagous beetles. Some species attack larvae of wood boring lepidoptera. In the present study, fifteen species belonging to eight genera of the subfamily Doryctinae are recorded for the first time from Korea: Doryctes Haliday (2 species), Eodendrus Belokobylskij (1 species), Heterospilus Haliday (4 species), Monolexis Förster (1 species), Neurocrassus Snoflak (2 species), Rhoptrocentrus Marshall (1 species), Sonanus Belokobylskij et Konishi (1 species), Spathius Nees (3 speices). The genera Eodendrus Belokobylskij, Monolexis Förster, Rhoptrocentrus Marshall, Sonanus Belokobylskij et Konishi and fifteen species are reported for the first times from Korea. Diagnosis and host information are provided.

• New & Renewable Energy
• /
• v.3 no.4
• /
• pp.22-30
• /
• 2007

An expansion device plays an important role in optimizing the heat pumps by controlling refrigerant flow and balancing the system pressures. Conventional expansion devices are being gradually replaced with electronic expansion valves due to increasing focus on comfort, energy conservation, and application of a variable speed compressor. In addition, the amount of refrigerant charge in a heat pump is another primary parameter influencing system performance. In this study, the flow characteristics of the expansion devices are analyzed, and the effects of refrigerant charge amount on the performance of the heat pump and the variation of compressor speed are investigated at various operating conditions. Mass flow rate through capillary tube, short tube orifice, and EEV was strongly dependent on the upstream pressure and subcooling. The heat pump system is very sensitive with a variation of refrigerant charge amount. The performance of it can be optimized by adjusting the flow rate through expansion device to maintain a constant superheat at all test conditions.

• International Journal of Safety
• /
• v.4 no.2
• /
• pp.6-11
• /
• 2005

The goals of the paper are to understand the impact damage behavior and identify the effect of surface protective materials on impact resistance in filament wound composite pressure vessels. For these, a series of low velocity impact tests was performed on specimens cutting from the full scale pressure vessel by the instrumented impact testing machine. The specimens are classified into two types, which are with and without surface protective material. The visualization for impact damage by two different impactors is made by metallurgical microscope. Based on the impact force history and damage, the impact resistance parameters were employed,rod its validity in identifying the damage resistance of filament wound composite pressure vessel was reviewed. As the results, the impact resistance of the filament wound composites and its dependency on the surface protective material were evaluated quantitatively

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.10
• /
• pp.741-744
• /
• 2013

In this study, we fabricated anodic aluminum oxide (AAO) membrane by two step anodizing process for pH detection. The structural properties were observed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). Electrochemical measurements of the pH sensor have been performed in capacitance-voltage (C-V) and drift rates. The characterization of AAO membrane exhibited high sensitivity (99.1 mV/pH) at second anodizing time of 4 min.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2015.07a
• /
• pp.3-4
• /
• 2015

본 논문에서는 공간 오디오 부호화 기법인 MPEG 서라운드에서 공간 파라미터 전송 시 위상 파라미터를 생략하는 기법에 대해 다룬다. 기존 방법에서는 한 프레임이 모두 적은 위상차를 가지는 경우에도 정상적으로 처리하여 전송한다. 이러한 경우 위상차 파라미터를 생략하여 비트 효율을 향상시킬 수 있다. 스테레오 복원 과정에서 발생하는 채널 간 시간차에 기반해 설계된 양자화기를 생략 기법에 적용하면 기존에 비해 평균적으로 40 ~ 50% 정도의 위상 파라미터 절감 효과를 얻을 수 있다.

• Journal of the Korean Magnetic Resonance Society
• /
• v.14 no.1
• /
• pp.1-8
• /
• 2010

Four 5,8-epidioxy sterols were isolated from the marine sponge Plakortis simplex. Their structures were completely determined by an extensive NMR analysis and comparison with NMR data of similar compounds for absolute stereochemistry of the side chain. The compounds were assigned as 5,8-epidioxy- (24S)-ethylcholesta-6,22(E),25-trien-3-ol(1), 5,8-epidioxy-(24S)-methylcholesta- 6,22(E)-dien-3-ol(2), 5,8-epidioxycholesta-6,22(E)-dien-3-ol(3) and 5,8- epidioxycholesta-6-en-3-ol (4).

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.816-818
• /
• 2005

In this paper, we have developed an hourly operating strategy for Direct load control (DLC) considering the efficiency of DLC program and increasing the utility of DLC resource. According to the operating code for DLC, the DLC center should curtail the load for 4 hours when the control notification has been enforced. Since the above strategy may limit the participation of entities, who intend to take part in the DLC program, the new strategy to mitigate the above limitation is required. In this paper, we have developed the operating strategy of DLC program and the mechanism to apply the proposed strategy in the DLC center. The proposed strategy makes the important role from the view of guaranteing the effective alternative raising the participation and avoiding the penalty of the entities.

• Journal of Chest Surgery
• /
• v.28 no.4
• /
• pp.431-436
• /
• 1995

Congenital esophago-bronchial fistula without atresia is very rare and usually demonstrate more insidious clinical effects, and patients may reach adult life before the diagnosis. We had been experienced a typical case of esophago-bronchial fistula without atresia and document the case. A 42-year-old women was admitted to our hospital due to frequent choking symptom and attacks of pneumonia, and patient status was in chronic pulmonary infection status such as most probably bronchiectatic state of right middle & lower lobe including significant destructive changes. We had confirmed esophago-bronchial fistula without atresia with esophagoscopy, esophagogram, and chest CT, and performed esophago-bronchial fistulectomy and right middle & lower lobectomy. Its belongs to type II of Braimbridge`s classification for congenital esophago-bronchial fistula. Postoperation course was smooth and uneventful.

• ETRI Journal
• /
• v.28 no.4
• /
• pp.509-512
• /
• 2006

In a real environment, sound recordings are commonly distorted by channel and background noise, and the performance of audio identification is mainly degraded by them. Recently, Philips introduced a robust and efficient audio fingerprinting scheme applying a differential (high-pass filtering) to the frequency-time sequence of the perceptual filter-bank energies. In practice, however, the robustness of the audio fingerprinting scheme is still important in a real environment. In this letter, we introduce alternatives to the frequency-temporal filtering combination for an extension method of Philips' audio fingerprinting scheme to achieve robustness to channel and background noise under the conditions of a real situation. Our experimental results show that the proposed filtering combination improves noise robustness in audio identification.

• ETRI Journal
• /
• v.28 no.4
• /
• pp.502-505
• /
• 2006

A new class-based histogram equalization method is proposed for robust speech recognition. The proposed method aims at not only compensating the acoustic mismatch between training and test environments, but also at reducing the discrepancy between the phonetic distributions of training and test speech data. The algorithm utilizes multiple class-specific reference and test cumulative distribution functions, classifies the noisy test features into their corresponding classes, and equalizes the features by using their corresponding class-specific reference and test distributions. Experiments on the Aurora 2 database proved the effectiveness of the proposed method by reducing relative errors by 18.74%, 17.52%, and 23.45% over the conventional histogram equalization method and by 59.43%, 66.00%, and 50.50% over mel-cepstral-based features for test sets A, B, and C, respectively.