• Fisheries and Aquatic Sciences
• /
• 제27권2호
• /
• pp.87-99
• /
• 2024

Global climate change, followed by an increase in anthropogenic activities in aquatic ecosystems, and species invasions, has resulted in a decline in aquatic organism biodiversity. The Batanghari River, Sumatra's longest river, is polluted by mercury-containing illegal gold mining waste (PETI), industrial pollution, and domestic waste. Several studies have provided evidence suggesting a decline in fish biodiversity within the Batanghari River. However, a comprehensive evaluation of the present status of biodiversity in this river is currently lacking. The species under investigation were identified through various molecular-based identification methods, as well as morphological identification, which involved the use of neighbor-joining (NJ) trees. All collected specimens were initially identified using morphological techniques and subsequently confirmed with molecular barcoding analysis. Morphological and DNA barcoding identification categorized all specimens (1,692) into 36 species, 30 genera and 16 families, representing five orders. A total of 36 DNA barcodes were generated from 30 genera using a 650-bp-long fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene. Based on the Kimura two-parameter model (K2P), The minimum and maximum genetic divergences based on K2P distance were 0.003 and 0.331, respectively, and the average genetic divergence within genera, families, and orders was 0.05, 0.12, 0.16 respectively. In addition, the average interspecific distance was approximately 2.17 times higher than the mean intraspecific distance. Our results showed that the COI barcode enabled accurate fish species identification in the Batanghari River. Furthermore, the present work will establish a comprehensive DNA barcode library for freshwater fishes along Batanghari River and be significantly useful in future efforts to monitor, conserve, and manage fisheries in Indonesia.

• Fisheries and Aquatic Sciences
• /
• 제27권8호
• /
• pp.515-524
• /
• 2024

The high economic value and demand for shark fin have significantly increased the vulnerability of the shortfin mako shark (Isurus oxyrinchus Rafinesque, 1810) population in the Indian Ocean, particularly in the southern region of Java and West Nusa Tenggara. This study utilized a length-based assessment method to evaluate the stock status of I. oxyrinchus. Over a span of eight years (2013-2021), data on length frequency and sex composition were collected. The length-based spawning potential ratio (SPR) was employed to investigate the stock status of the fishery. The findings revealed that I. oxyrinchus exhibited a large body size, with an asymptotic length estimated at 386.86 cm total length and a growth coefficient of 0.04/year . Females were more frequently captured than males, and evidence indicated a declining trend in the size of female sharks. A low SPR value of approximately 6% indicated the overfishing condition of mako shark. To ensure the sustainability of the shortfin mako shark population in the Indian Ocean, it is essential to develop effective management strategies through integrated cooperation among the government, fishers, traders, shark industries, and local communities.

• Fisheries and Aquatic Sciences
• /
• 제27권4호
• /
• pp.213-224
• /
• 2024

Betta rubra, classified as endangered fish species by the International Union for Conservation of Nature (IUCN), has been successfully bred and raised in captivity for two generations under laboratory conditions. This study aimed to provide comprehensive information on the captive breeding of B. rubra, focusing on various parameters crucial for ex-situ conservation and domestication. The research involved breeding trials, embryo and larvae observation, first feeding experiments, larva and fry rearing trials, and the evaluation of growth and reproduction in two generations. The study revealed that the female B. rubra, with an average total length of 5.17 ± 0.15 cm and weight of 1.61 ± 0.06 g, produced an average of 73.67 ± 7.09 eggs, 34.33 ± 5.13 total larvae, and exhibited a hatching rate of 46.67 ± 5.77%. The embryogenesis process commenced on the day of spawning (dps) and continued until the eggs hatched at 6 dps. Larvae development and yolk absorption occurred from 0 to 6 days post-hatching (dph). The study also examined the impact of different initial feeding options, with chopped Tubifex resulting in the most significant in- crease (p < 0.05) in length. The growth pattern of B. rubra larvae showed slow initial growth during the first seven days, followed by a rapid exponential growth phase from day 8 to day 39. Two generations of B. rubra (G1 and G2) were successfully bred in captivity, with G2 showing a better tendency for growth in length and weight compared to G1. Notably, there were no significant differences (p > 0.05) in reproductive success between the wild-origin broodstock (G0), G1, or G2. This research contributes valuable insights into the captive breeding of B. rubra and its early life stages, offering critical information for the conservation and sustainable management of this endangered species. Further research is needed to explore the long-term effects of domestication on behavior, physiology, and phenotypic diversity.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2008년도 하계종합학술대회
• /
• pp.411-412
• /
• 2008

The high performance 94 GHz MMIC(Monolithic Micro-wave Integrated Circuit) single balanced mixer was designed and fabricated, using MHEMT structure based diodes and a CPW(Coplanar Waveguide) tandem coupler. A novel single-balanced structure of diode mixer is proposed in this work, where a 3-dB tandem coupler with two section of parallel-coupled line. Implemented air-bridge crossover structures achieve wide frequency operation and the fabricated mixer exhibits excellent LO-RF isolation, larger than 30 dB, in the 5 GHz bandwidth of 91-96 GHz. A good conversion loss of 7.4 dB is measured at 94 GHz. The proposed MHEMT-based diode mixer shows superior LO-RF isolation and conversion loss to those of the W-band mixers reported to date.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.491-492
• /
• 2006

The MMIC (Microwave Monolithic Integrated Circuit) self oscillating double conversion mixer was designed and fabricated for the V-band transmitter applications. The MMIC self oscillating double conversion mixer which dose not need external local oscillator was designed using GaAs PHEMT technology. The first self oscillating mixer use PHEMT technology. The first self oscillating mixer use PHEMT for $f_{LO}$ signal generation and $f_{IF}$ signal is applied at gate port and $f_{RF1}$ signal is generated at a drain port of first stage. The second gate mixer use PHEMT for $f_{LO}$ signal and $f_{RF1}$ signal is applied at gate port and $f_{RF2}$ signal is output at a drain port of second stage.

• 통상정보연구
• /
• 제12권2호
• /
• pp.325-355
• /
• 2010

Knowledge-based exporting companies in Korea have reached a stage to develop new technological innovation and to pioneer new markets. But, developing new technologies and launching new products require an enormous sum of money for Research and Development(R&D) and there is still uncertainty in technological development and markets. Therefore, through open technological innovation, they are encouraged to actively use external technological sources and ideas. They also need to enhance the efficiency of the relatively little R&D investment. In this paper, firstly, it conducts a precedent study on the concept and influence factors of knowledge-based exporting companies and open technological innovation. Secondly, it sets a study model and estimates a regression coefficient to analyze the influence factors of open technological innovation of knowledge-based exporting companies which are using external resources on the process of innovation. Through case study and empirical analysis, we are going to find the implication of open technological innovation and prepare the way of the innovation for the knowledge-based exporting companies. According to the empirical analysis, variables such as firm size, processing degree, product life, patent registration, maintaining internal security didn't have positive effects on open innovation performance. On the other hand, research capability and market preoccupancy had positive effects. Therefore, to succeed in open innovation, knowledge-based exporting companies not only need to secure research capability through open innovation, but also need to preoccupy the market through commercialization of developed product.

• 지식경영연구
• /
• 제16권4호
• /
• pp.1-16
• /
• 2015

This paper aims to explore the small and medium sized enterprises'(SMEs') technological innovation through an open innovative strategy. Researchers have identified open innovation as external search 'breadth' and 'depth'. Although an open innovation strategy is well known as an effective way for SMEs' innovation, this stream of research examines differences between pursuing breadth of external knowledge and depth of external knowledge for SEMs' innovation. The sample comprises a total of 1106 SMEs included in the Korean Innovation Survey, and logistic regression analysis and odds ratio comparison were used to evaluate the relationship between external knowledge search and innovation outcomes. The results show that both 'breadth' and 'depth' positively affect the SMEs' innovation. When SMEs are simultaneously pursuing external searching for breadth and depth, however, a negative result on innovation outcome followed because of the lack of their internal resources and capacities. Despite these contributions, we have certain limitations that can be regarded as means of future research. Even though breadth and depth are adopted to measure the way of how a firm sources the external knowledge, companies may place the different weight on each source of knowledge. And also, it is difficult to understand how the knowledge gained through external search contributes to a firm's incremental and radical innovation, respectively.

• Asia pacific journal of information systems
• /
• 제12권3호
• /
• pp.135-167
• /
• 2002

This research focuses on the IS development methodology as an object of innovation in an IS organization. It has two main research objectives. It was intended to understand the critical affecting factors which have an effect on the processing of each level in the dynamic and evolving innovation process. There are two levels of innovation process: initiation and implementation. It was also intended to understand the performance of IS organizational innovation. We found three main results by the LISREL analysis. First, main factors affecting initiation level of innovation are innovative tendency of IS members, communication level of IS organization, existence of champion manager, IS performance gap, executive supporting to IS, and relative advantage of IS development methodology. At the implementation level, it was understood that the existence of champion manager, executive support, and relative advantage of IS development methodology were the main factors promoting to use the innovation, and the complexity of innovation was a negative factor adopting the usage of innovation. Second, the quality of the previous level in the gradual innovation activities gives very notable affection to the continuous next level. Finally, it was found that the qualitative performance like the documentation, collaborative team approach, IS developer's awareness and ability corresponding to their task and so on was improved due to the IS organizational innovation. This research provides the standard framework for the IS organizational innovation in a structural way. In the practical aspect, it may be used as the principle for introducing and using the IS development methodology.

• 기술혁신연구
• /
• 제12권2호
• /
• pp.127-150
• /
• 2004

This article examines the issue of utilization of research findings from public funded research institutions (PRIs) and universities in Malaysia from the perspective of knowledge flows. Such a perspective is adapted from the literature on innovation and knowledge systems. This representation of innovation in terms of knowledge flows helps us to focus on the managerial dimensions involved in the organization of activities such as research and development (R&D). The paper reveals that there is a dismal rate of adoption of research findings generated from PRIs and universities in Malaysia. It is argued that this poor performance is a consequence of weak research management practices. A framework on the key elements of sound research management is described. The article concludes with a discussion on managerial and policy issues arising from these deficiencies and some suggestions for addressing them.

• 대한전자공학회논문지TC
• /
• 제41권4호
• /
• pp.45-50
• /
• 2004

본 논문에서는 소자 결합 구조를 통해 발진전력이 합쳐지는 회로를 이용한 저전압, 고효율 Q-band MIMIC 발진기를 제안한다. 0.1 ㎛ GaAs PHEMTS와 CPW 전송라인을 사용하여 제안된 구조의 발진기를 성공적으로 집적화하였다. 제작된 발진기는 34.56 ㎓ 주파수에서 2.6 ㏈m의 출력 전력일때 19 %의 높은 효율특성을 가졌다. 이때 회로에 인가된 전압은 2.2 V로 현재까지 Q-band에서 발표된 발진기보다 낮은 구동전압 특성을 얻었다. 또한 최대 출력 전력은 34.56 ㎓ 주파수에서 6.7 ㏈m을 얻었다.