• Applied Microscopy
• /
• v.29 no.2
• /
• pp.223-230
• /
• 1999

The epithelium of the rectum in the mosquito larvae, Culex pipiens pallens: Culicidae, was observed with electron microscope. The rectum of posterior hindgut was composed of epithelial tissue which were covered with cuticular intima on the luminal side, connective tissue and muscular tissue. The rectal epithelial cells were squamous absorptive cells, and apical plasma membranes were highly folded to form apical infoldings with mitochondria inserted them. The lateral plasma membranes were irregularly infolded and well developed mitochondria were found closely associated with infoldings . And intercellular spaces (or channels) were formed between the epithelial cells, whereas speptate junction was found near the apical zone between them. Also basal plasma membrane were infolded which made basal infoldings ('basal labyrinth'), and were covered with thin basal lamina. Rcetal epithelium was surrounded by the connective tissue which was contained axon and tracheole cells. Connective tissue was covered with the bundles of circular and longitudinal muscles.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1998.10a
• /
• pp.68-111
• /
• 1998

The structure of the Hanwoo (Korean Native Cattle) Industry remains very weak and vulnerable to the WTO/IMF system. Considering that the majority of cattle farmers are small sized, and that marketing systems are outdated and inefficient, rapid expansion of lower priced beef imports by WTO system and rapid increasing of production costs by IMF system would lead to the deprivation of a regular source of farm income and threaten the stability of rural life. Accordingly, the Hanwoo industry should be expanded in accordance with progress in the implementation of (1) programs for the structural adjustment and (2) measures to compensate for the loss. Efforts for lowering major production factor costs needs to continue, In order to increase the supply of calves at low cost, the programs of collective cow-calf farms should be expanded, thereby reducing the cost of calf purchase, which constitutes the largest share of Hanwoo production cost. Also, feedlot operations should be encouraged for small herd farms in order to achieve a substantial saving in beef production costs by integrated operations from calf production to cattle fattening. A substantial saving would also be made by collective purchase and distribution of various inputs through the cooperatives' channels. Extension services should be strengthened for cattle farm management, cattle care and feeding, prevention of cattle disease, etc. In order to minimize cash outlays for commercial mixed feeds, utilization of far by-products as feeds should be enhanced and production of forage crops productive of resources, such as land and rural labor, during the farm o(f-season, needs to be encouraged. Also, technological development for enhancing the nutritional value of farm by-products should be encouraged. Measures for successful segregation of the Hanwoo beef market should be implemented, thereby enhancing incentive for quality beef producers and protecting consumers willing to pay higher price for quality beef. For development of the Hanwoo industry, a considerable time frame would be required in order for (1) small livestock farmers to make a successful adjustment by staying in the enterprise and achieving increased price efficiency (2) livestock farmers to acquire know-how for producing quality Hanwoo beef, (3) the ongoing Government policy of enhancing price-quality competitiveness, and for improving the quality Hanwoo beef marketing to take root. (4) consumers to increase their ability to distinguish meat quality, and others.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.2
• /
• pp.488-495
• /
• 2014

The national defense electronic procurement system is an information system supporting DAPA, services (Army, Navy and Air Force), and the procurement companies in the electronic bidding. It has contributed greatly to improving the efficiency of the national defense electronic procurement process by providing various information services based on inter-operation among the related parties. However the national defense electronic procurement system is expected to be upgraded to the next version in accord with rapidly evolving infrastructure based on high technology and increasing various communication channels. This paper investigates the satisfaction level of the system users and proposes directions for the next-generation procurement portal.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2812-2817
• /
• 2013

In this paper, an outage probability for the best relay selection in decode-and-forward relaying systems in the presence of interference is analyzed over Rayleigh fading channels. Based on the outage performance results, we propose a method to determine effective relay candidates for the best relay selection, where the effective relay candidates represent the relays except for relays that make no contribution to improving the performance. in all possible relays given in the system. By determining the effective relay candidates, the feedback overhead of channel state information and the energy consumption of relays can be significantly reduced while minimizing the performance degradation. In this paper, we provide important parameters that affect the determination of the effective relay candidates.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.8
• /
• pp.1589-1596
• /
• 2017

In synchronous secure communications, a synchronization signal is transmitted over the same channel where ciphertext is transmitted for cryptographic synchronization between an encryptor and a decryptor, so, it causes data rate lowering and transmission delay for plain communication. Especially, in poor environments such as wireless channels and so on, since secure communications require a periodic resynchronization protocol, synchronization signal transmission method can dominate its quality. In this paper, we proposed a new synchronization signal transmission method without additional bandwidth as well as resynchronization protocol based on it. We embeded a synchronization signal as a watermark in a transmission image and restored it from a detected watermark in the decryptor. Experimental results of image have demonstrated that the proposed synchronization signal transmission method using watermarking is efficient in transmission rate and can support reliable synchronization detection.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.3
• /
• pp.513-519
• /
• 2018

OFDM modulation has been used for a transmission scheme in 4G LTE (Long Term Evolution) and Wi-Fi systems to mitigate the effects of frequency selective fading channels. An OFDM modulation is a block transmission scheme because an OFDM symbol consists of multiple subcarriers with narrow bandwidth. Therefore, all OFDM symbols in a frame should be filled out with data and padding bits. Depending on the amount of data, more padding bits than information bits can occupy the last OFDM symbol. Such inefficiency causes the loss of throughput. To overcome this problem, an efficiency padding method is proposed by using the property of DFT (Discrete Fourier Transform). In the proposed method, symbol duration of the last symbol is changed depending on the number used data subcarriers in the last symbol. With numerical evaluation, it is examined that throughput enhancement achieved by the proposed method can be about 20% depending a transmission scheme and data length.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.1
• /
• pp.60-67
• /
• 2016

A pressurized heavy water reactor (PHWR) designed to refuel in service produces the energy required by nuclear fission. The fuel channel consists of components such as a pressure tube which directly contacts the fuel and is a passage for the reactor coolant, a calandria tube which contacts the moderator and is rolled joint with calandria, and a spacer which is not to contact the pressure tube and a calandria tube. As the fuel channel is one of the most important equipments, it requires accurate and periodic inspections to assess the integrity of a reactor in accordance with CSA N285.4. A fuel channel inspection system is developed to inspect fuel channels during in-service inspection in Wolsong unit. In this paper, the results and considerations of a field test are presented in order to show the effectiveness of the developed fuel channel inspection system.

• Journal of Internet Computing and Services
• /
• v.16 no.5
• /
• pp.93-98
• /
• 2015

IoT (Internet of Things) is recently burgeoning as business applications as well as ICT itself. Among the business applications of IoT, wearable devices are recognized as a leading area of customer devices. This research first identifies customer needs of activity trackers (fitness trackers), as one of representative wearable devices, and mapping the identified needs with the well-known marketing model of marketing mix (4 P's: Product, Price, Promotion, and Place). Survey was applied to university students for identifying current and potential needs for activity trackers. The needs were classified by 4 P's, and according to the results, different from other IT devices, activity trackers has more potential needs. Moreover, reliable distribution channels, offline and company owned shops were preferred, rather than online shopping mall by third parties. The results would provide some valuable implications to not only designers of activity trackers but also business management.

• Journal of Fashion Business
• /
• v.12 no.3
• /
• pp.153-166
• /
• 2008

The purpose of this research is to analyze the overall process of the wedding industry - arranging domestic wedding firms and formulating a database related to the business. Simultaneously, with all the data in hand the research attempts to seek flaws within the wedding industry and tries to offer solutions to revitalize the industrial section. Because the list of articles is enormously expansive, for the purpose of basic research, objects have been selected according to the process presented below. Wedding-product firms have been classified within the boundaries of dresses, studios, and makeup firms; distributing channels are mainly focused on wedding planners and related-consulting firms; related departments of universities and wedding organizations are illustrated as well. Due to the unorganized system of this particular field, the research process has been conducted with materials from personal experiences, newspapers, magazines, Internet websites, documents, and interviews with wedding-related firms and organizations, and professors. As a result, over 13 subjects which formulate a market structure of over 30 trillion won. However, due to lack of systemization of the industry, as it expands, numerous problems occur. Excessive competition between wedding-consulting firms and the lack of reliable education for wedding planners, unnecessary external investment and the lack of product research, false Information from the Internet puts the entire industry in a inefficient position. Organizations such as Korea Traditional clothes Industrial Union, Korea Wedding Consulting Association, Korea Martial Industrial Promotion Association(KOMIPA) etc, are made to seek for solutions. For the wedding industry to revitalize, wedding-product firms, wedding planners and consulting firms must maintain an organic relationship every season. They must systemize a proper distribution system, with wedding-product companies enhancing the quality of products, wedding planners organizing wedding plans with responsibility, and consulting firms focusing not only on profits. In order to make high-valued products, wedding-product companies must put their greatest effort in producing talented minds, and universities with related departments must do so as well. In other words, the industrial and educational section of our society must cooperate through a sophisticated system. In addition, related organizations must act to receive governmental support in order to support the industry.

• Journal of Advanced Navigation Technology
• /
• v.10 no.3
• /
• pp.205-212
• /
• 2006

In this paper, the numerical methods of searching the optimal position of optical phase conjugator (OPC) and the optimal dispersion coefficients of fiber sections are proposed, which are able to effectively compensate overall channels in $8{\times}40$ Gbps WDM system with non zero - dispersion shifted fiber (NZ-DSF) as an optical fiber. And the compensation characteristics in the system with two induced optimal parameters are compared with those in the system with the currently used mid-span spectral inversion (MSSI) in order to verify the availability of the proposed methods. It is confirmed that the compensation extents of the distorted 8-channel signals are improved within 2 dB power penalty by applying the induced optimal parameters into WDM system. It is also confirmed that two optimal parameters less related with the searching procedure of these optimal values, only if these depend on each other.