Factors Influencing the Success of Farmers’ Community Group for Rural Agricultural Development in Bali Province, Indonesia

Dede Wahyu Fahmi Muharam,Hwa-Soek Hwang,Dong-Hyun Shin 한국국제협력단 2020 국제개발협력 Vol.15 No.2

Population growth in Indonesia is quite high, and this condition can cause an increase in poverty levels with a high level of urbanization. Rural development, which is closely related to agricultural development, can be one solution to this problem. Agricultural development in rural areas is closely related to farmers’ community groups. For these reasons, such groups have a very important role in the development of rural areas and the agricultural sector, eventually contributing to the development of the economy. This study determines the most important factors influencing the success of a farmers’ community group in Indonesia. Based on the results of regression calculations with the 95% confidence level, there are two significant variables, namely the years of operation of each community group (X₂) and the previous experience of groups as institutions (subak) (X₅). If the years of existence increases by 1 year, the score representing the success of the farmer group will increase by 7.329 points and conversely so. If the group was formerly a subak, the level of success of the farmers’ community group would increase by 8.89 points.

Mineral phase, microstructure, and Infra-Red characteristics of calcia-stabilized zirconia nanocrystallines synthesized from local zircon and slaked lime

Dede Taufik,Mikrajuddin Abdullah,Hernawan,Suhanda Sutardi,Rifki Septawendar 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.10

Nanocrystallines of calcia-stabilized zirconia are known to reveal excellent mechanical and high ionic conductivity propertieswhose depend on the calcia concentration. In this work, nanocrystallines of calcia-stabilized zirconia were synthesized fromzircon precursor and 7.5 weight % CaO at 1000 oC, 1200 oC, and 1400 oC. Phase transformation and microstructure evolutionwere investigated by an X-ray diffraction and a scanning electron microscopy. Another un-doped zirconia was also synthesizedfrom the local zircon by following the same procedure for comparison. A fully cubic form of the calcia-stabilized zirconia andcalcium zirconate were obtained at 1200°C having the crystallite sizes ranging from 55 to 87 nm and remained stable at1400 oC. Meanwhile, un-doped zirconia consisted of pure the monoclinic zirconia at 1200 oC and 1400 oC. High agglomerationis found in the calcia-stabilized zirconia particles at 1000 oC, whereas grain boundaries and interconnect are observed at1400 oC. The cubic crystal of zirconia has specific and different finger print characteristics in the infra-red spectrum comparedto the monoclinic zirconia.

Resistance of Polystyrene-Impregnated Glued Laminated Lumbers after Exposure to Subterranean Termites in a Field

Dede Hermawan,Mahdi MUBAROK,Imam Busyra ABDILLAH,Yusuf Sudo HADI,Cossey YOSI,Aujchariya CHOTIKHUN,Rohmah PARI,Gustan PARI 한국목재공학회 2024 목재공학 Vol.52 No.1

Termites are a serious threat to wood-based products in Indonesia. This study investigated the termite resistant property of glulam made from polystyrene-modified wood. Three tropical fast-growing wood species, namely mangium (Acacia mangium), manii (Maesopsis eminii), and rubberwood (Hevea brasiliensis), were prepared for flat-sawn laminae. After getting air-dried condition, the laminae were impregnated with polystyrene using potassium peroxydisulphate as a catalyst followed by polymerization at 80℃. Polystyrene-impregnated and control glued-laminated lumbers (glulams) were manufactured, and solid wood was provided. Three wood species and three wood products with six replicates were exposed in a field in Bogor, Indonesia, for four months, and before the tests, their density and moisture content were measured. At the end of the field tests, the weight loss and protection levels of each test sample were determined. A completely randomized factorial design was used for data analysis. The weight percentage gains for mangium, manii, and rubberwood were 22.30%, 18.22%, and 10.44%, respectively. The results showed that manii belonged to low-density wood, whereas the other two woods were medium-density wood, and the moisture content was the ambient moisture content, typical of the Bogor area. Regarding weight loss and protection level, mangium was the most durable against subterranean termite attacks, followed by rubberwood and manii. Among the wood products, the polystyrene-impregnated glulam presented the highest durability, followed by the control glulam and solid wood. Therefore, mangium and rubberwood polystyrene-impregnated glulams are recommended for future product development.

Oscillatory Transformative Domain Wall Inner Structure of the Depinning Domain Wall Around a Notched Ferromagnetic Wire

Dede Djuhana,Bambang Soegijono,Hong-Guang Piao,Suhk Kun Oh,Seong Cho Yu,김동현 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

We have investigated the domain wall (DW) depinning behavior around the symmetric notches inferromagnetic nanowires by means of a micromagnetic simulation. We observed that the depinningfield decreases as the size of the notch increases. The change in the ratio of the height to the lengthof the bottom of the triangular notch is also considered, and a relatively insensitive variation of thedepinning field is observed with for ratios greater than 2. When the depinning field strength is varied,the DW internal structure is found to change during the depinning process. At a lower depinningfield (< 4 mT), the DW keeps its initial transverse wall structure whereas at a higher depinningfield (> 4 mT), the DW is depinned with a transformation of the inner structure with an antivortexsoon after the DW has escaped from the notch due to the Walker breakdown phenomenon. Veryinterestingly, with any external field, the depinned DW with antivortex inner structure is observedto move back to the original notch position. This is explainable because the notch acts as anattractive pinning potential for the DW.

Micromagnetic Study of Magnetic Ringing Trapped at Nanocontact After Domain Wall Collision in Ferromagnetic Nanowire

Dede Djuhana,Hong-Guang Piao,Sang Hyuk Lee,Dong-Hyun Kim 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

A teaching learning based optimization for truss structures with frequency constraints

Dede, Tayfun,Togan, Vedat Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.4

Natural frequencies of the structural systems should be far away from the excitation frequency in order to avoid or reduce the destructive effects of dynamic loads on structures. To accomplish this goal, a structural optimization on size and shape has been performed considering frequency constraints. Such an optimization problem has highly nonlinear property. Thus, the quality of the solution is not independent of the optimization technique to be applied. This study presents the performance evaluation of the recently proposed meta-heuristic algorithm called Teaching Learning Based Optimization (TLBO) as an optimization engine in the weight optimization of the truss structures under frequency constraints. Some examples regarding the optimization of trusses on shape and size with frequency constraints are solved. Also, the results obtained are tabulated for comparison. The results demonstrated that the performance of the TLBO is satisfactory. Additionally, TLBO is better than other methods in some cases.

Structural optimization with teaching-learning-based optimization algorithm

Dede, Tayfun,Ayvaz, Yusuf Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.4

In this paper, a new efficient optimization algorithm called Teaching-Learning-Based Optimization (TLBO) is used for the least weight design of trusses with continuous design variables. The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several truss structures are analyzed to show the efficiency of the TLBO algorithm and the results are compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectively used in the weight minimization of truss structures.

Improving the success of direct seeding through the application of seed briquettes, aquasorb, and sowing time: case studies on Ceiba pentandra, Enterolobium cyclocarpum, and Calophyllum inophyllum

Dede J. Sudrajata,Evayusvita Rustam,Nurhasybi,Nurin Widyani,Yulianti,Yupi Isnaini,Popi Aprilianti,Enggal Primananda,Muhammad Zanzibar,Suhartati,Kurniawati P. Putri,Naning Yuniarti,Surono,Vivi 한국산림과학회 2023 Forest Science And Technology Vol.19 No.2

Direct seeding, a planting technique that has long been applied in restoring degraded land and forest, is often doubted to be successful due to many constrains, both biotic and abi- otic. This study aims to increase the success of direct seeding through the application of seed briquettes, aquasorb treatment and determining the right sowing time for three forest tree species, i.e. Ceiba pentandra, Enterolobium cyclocarpum, Calophyllum inophyllum.This study used a randomized block design with two factorials (seed treatments and sowing dates) in each species. Seeds were sown in three blocks in the field according to the sowing time treatments. Each treatment consisted of 10 sowing plots in one block and 5 seeds or seed briquettes in each sowing plot. The results showed that direct seeding when the rain starts to stabilize (ST-2) supported by the use of seed briquettes and the addition of aqua- sorb was able to increase seedling survival, height and root collar diameter of all tested tree species. In general, seed briquettes and the addition of aquasorb provided better seedling survival and growth compared to direct seeding using untreated seeds. C. inophyllum gave higher seedling survival compared to the other two species indicating that this species is very prospective for direct seeding applications due to its high adaptability.

Ifosfamide and Doxorubicin Combination Chemotherapy for Recurrent Nasopharyngeal Carcinoma Patients

Dede, Didem Sener,Aksoy, Sercan,Cengiz, Mustafa,Gullu, Ibrahim,Altundag, Kadri Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Background: We assessed the efficacy and toxicity of ifosfamide and doxorubicin combination chemotherapy (CT) regimen retrospectively in Turkish patients with recurrent or metastatic nasopharyngeal carcinoma (NPC) previously treated with platinum-based chemotherapy. Methods: A total of thirty patients who had received cisplatin based chemotherapy/chemoradiotherapy as a primary treatment received ifosfamide 2500 $mg/m^2$ days 1-3, mesna 2500 $mg/m^2$ days 1-3, doxorubicin 60 mg/m2 day 1 (IMA), repeated every 21 days. Eligible patients had ECOG PS< 2, measurable recurrent or metastatic disease, with adequate renal, hepatic and hematologic functions. Results: Median age was 47 (min-max; 17-60). Twenty six (86.7 %) were male. Median cycles of chemotherapy for each patient were 2 (range:1-6). Twenty patients were evaluable for toxicity and response. No patient achieved complete response, with nine partial responses for a response rate of 30.0% in evaluable patients. Stable disease, and disease progression were observed in five (16.7%) and six (20.0%) patients, respectively. Clinical benefit was 46.7%. Median time to progression was 4.0 months. Six patients had neutropenic fever after IMA regimen and there were one treatment-related death due to tumor lysis syndrome in first cycle of the CT. No cardiotoxicity was observed after CT and treatments were generally well tolerated. Conclusion: Ifosfomide and doxorubicin combination is an effective regimen for patients with recurrent and metastatic NPC. For NPC patients demonstrating failure of cisplatin based regimens, this CT combination may be considered as salvage therapy.

Micromagnetic study of domain wall depinning driven by nanosecond current pulse in notched Permalloy nanowire

Dede Djuhana,Candra Kurniawan,김동현 한국물리학회 2018 Current Applied Physics Vol.18 No.2

The complete understanding of domain wall (DW) dynamics is important in the design of future spintronic devices. The characteristics of faster time-scale and lower current amplitude to move DW along nanowire are crucial in fabrication upgrade. In this study, we have investigated depinning behavior of magnetic domain wall triggered by nanosecond current pulse in notched Permalloy nanowires by means of micromagnetic simulation. We introduced double-triangular notch as the constrictions in the nanowire. The non-adiabaticity of the spin-transfer-torque is considered in simulation by varying the non-adiabatic constant (β) value. We observed that the depinning current density (Jd) was not significantly affected by β for notch size (s) < 50 nm. Interestingly, we found that the depinning time (td) for β ≥ 0.04 was slightly constant for all the cases with s > 70 nm, where the DW structure was kept to be a transverse structure during the depinning process. The broadly applicable depinning behavior is considered to contribute to the development of high-speed memory storage devices based on magnetic domain wall.