Irregular labeling on transportation network of splitting star graphs

NURDIN,김혜경 장전수학회 2019 Proceedings of the Jangjeon mathematical society Vol.22 No.1

The management of land transportation system in a city is very important to do so that there is no congestion on road segments or at road intersections. To optimize the management of land transporta- tion system we requires an appropriate and ecient design/model. In this study, the land transportation system is modeled as a labeled graph. A graph is a set of vertices and a set of edges, where the vertices of the graph represent road intersections and the edges represent links between two road intersections. A vertex irregular total k-labeling on a graph G is a mapping that maps the set of all vertices and edges from G to the set of integers f1; 2; ::::; kg such that all vertices have dierent weight. The minimum k for which the graph G has an vertex irregular total k-labeling is called the total vertex irregularity strength of the graph G. This minimum integer is very useful when displaying the minimum travel time on certain roads. In this paper, we consider the splitting graph of stars as a land transportation system and give the exact value of their total vertex irregularity strength.

Photoelectrocatalysis performance of Se doped-TiO2/Ti nanotube arrays for visible-light-driven degradation of diazinon pesticide

Nurdin Muhammad,Watoni Abdul Haris,Natsir Muhammad,Rahmatilah Sarifa,Maulidiyah Maulidiyah,Wibowo Dwiprayogo,Salim La Ode Agus,Sadikin Siti Naqiyah,Bijang Catherina Manukpadang,Umar Akrajas Ali 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.9

The modification of ternary metal oxide to improve the photoelectrocatalysis (PEC) properties of TiO2 photocatalyst is a hot issue in environmental and resource applications. Herein, we present a novel photoelectrocatalytst of Se doped-TiO2/Ti nanotube arrays (Se@TiO2/Ti-NTAs) for high-efficiency degradation of diazinon pesticide. The Se@TiO2/Ti-NTAs were prepared to treat the TiO2-NTAs in Se-TiO2 sol-gel for 10 min, which was followed by calcination in air at 200 °C for 1 h. Optical absorption spectroscopy of the Se@TiO2/Ti-NTAs indicated that there is a red-shift in the optical energy gap to 2.95 eV if compared to the pristine TiO2/Ti NTAs, which suggests that the new photoelectrocatalyst is photoactive under visible light irradiation. We evaluated the photoactivity of the sample by using it as the photoelectrocatalyst in the degradation of diazinon pesticides under the PEC process. The results showed that the Se@TiO2/Ti-NTAs can degrade 95.62% for 1 h under visible light irradiation, which is equivalent to the degradation rate constant of 0.0183 s−1. For comparison, the pristine TiO2/Ti NTAs only degrades the diazinon as high as 87.65%, even then under UV light irradiation. Our result also indicated that the Se@TiO2/Ti-NTAs promote active photoelectron transfer and active radical formation, such as •OH and •O − 2 , for rapid diazinon pesticide degradation. The Se@TiO2/Ti-NTAs photoelectrode should be a potential platform for environmental pollution treatment.

Diverse and predominantly sub-adult Epinephelus sp. groupers from small-scale fisheries in South Sulawesi, Indonesia

Nadiarti Nurdin Kadir,Aidah A. Ala Husain,Dody Priosambodo,Muhammad Jamal,Irmawati,Indrabayu,Abigail Mary Moore 한국수산과학회 2023 Fisheries and Aquatic Sciences Vol.26 No.6

Groupers (Family Epinephelidae) are commonly caught in data-poor small-scale multi-species fisheries for sale on both export and domestic markets. This study presents data on the species composition and size/life-stage structure of Epinephelus spp. groupers caught by small-scale fishers and sold locally in the Indonesian province of South Sulawesi. Data were collected from fishing ports and local markets at 12 sites representing the three seaways around South Sulawesi (Makassar Strait, Flores Sea, Gulf of Bone). Each specimen (n = 3,398) was photographed alongside an object of known length, and total length (TL) was obtained using the Rapid Scaling on Object (RASIO). Of the 23 species identified, four (Epinephelus areolatus, Epinephelus ongus, Epinephelus quoyanus, and Epinephelus fasciatus) collectively comprised 69% of the catch, while the 13 least abundant species contributed less than 5%. The catch was dominated (67%) by the subadult life-stage, with just under 20% in the adult class. Juveniles dominated the catch of Epinephelus fuscoguttatus, a valuable export commodity. Observations of early maturity as well as the sizeable gap between length at first capture (Lc) and length at first maturity (Lm) indicate recruitment overfishing of most species, with the notable exception of Epinephelus rivulatus. The proportion of adult fish was low (≈5%–30%) for the twelve most abundant species (E. areolatus, E. ongus, Epinephelus quoyanus, E. fasciatus, Epinephelus coioides, Epinephelus faveatus, Epinephelus sexfasciatus, Epinephelus maculatus, Epinephelus bleekeri, Epinephelus corallicola, E. fuscoguttatus, Epinephelus polyphekadion). For two moderately abundant species (E. faveatus and E. malabaricus), TL < Lm for all specimens. The limited data available indicate spawning ratio is lower than reported from deep-water fisheries of E. areolatus and E. coioides. The results call for targeted research to fill knowledge gaps regarding the biology and ecology of groupers exploited mainly for domestic markets; highlight the need for species-level data to inform management policies such as minimum legal size regulations; and can contribute towards species-level status assessments.

Estimation of Seagrass Biomass by In Situ Measurement and Remote Sensing Technology on Small Islands, Indonesia

Nurjannah Nurdin,Khairul Amri,Supriadi Mashoreng,Teruhisa Komatsu 한국해양과학기술원 2022 Ocean science journal Vol.57 No.1

As one of the major blue carbon ecosystems, studying, conserving, and monitoring seagrass meadows, especially on small populated islands, has become very important due to their vulnerability to anthropogenic and global environmental factors. In this study, we used satellite image analysis and biological data to map seagrass percent cover (SPC), above-ground biomass (AGB), and below-ground biomass (BGB) on the three most populated islands of the Spermonde Archipelago, Indonesia, i.e., Kodingareng Lompo, Barrang Lompo, and Barrang Caddi. Reflectance and Normalized Difference Vegetation Index (NDVI) values of Sentinel-2 (S2) imagery were used to classify and calculate SPC and AGB. In situ biological data measurements were carried out from 3 to 14 of June, 2020, on the three islands to measure AGB and BGB. The result from image classification shows a total area of 126.37 Ha of seagrass, which was divided into three SPC categories: medium (30–59.9%) with a total area of 78.38 Ha; low (0–29.9%) with a total area of 13.1 Ha; and high (60–100%) with a total area of 34.89 Ha. The highest SPC area was observed on Kodingareng Lompo Island with 61.07Ha, followed by Barrang Lompo Island with 53.18Ha, and Barrangcaddi Island with 12.12Ha. The total AGB on Barrang Lompo, Kodingareng Lompo, and Barrangcaddi in tons of dry weight/ha were 1.83, 1.05, and 2.38, respectively. The highest BGB was reported on Barrangcaddi Island with 8.61 tons of dry weight/ha, followed by Barrang Lompo Island with 6.78 tons of dry weight/ha, and Kodingareng Lompo Island with 2.78 tons of dry weight/ha. Regression analysis showed a linear correlation between NDVI value and in situ SPC with R2 = 0.8255. The framework of this study can be applied to monitor temporal changes of seagrass meadows distribution on small islands to promote a more sustainable ecosystem.

Nanocomposite design of graphene modified TiO2 for electrochemical sensing in phenol detection

Muhammad Nurdin,Maulidiyah Maulidiyah,Abdul Haris Watoni,Armawansa Armawansa,La Ode Agus Salim,Zul Arham,Dwiprayogo Wibowo,Irwan Irwan,Akrajas Ali Umar 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.1

This study is the stage of developing a phenol detection electrochemical sensor. Phenol is one of the organic pollutants harmful to human life and ecosystems. The development of this sensor was carried out by studying the use of TiO2 anatase as a modifier of graphene electrodes. The mass of TiO2 anatase was varied, while the mass of graphene and paraffin was fixed. The results showed that the TiO2 mass of 1.0 g was the best mass as a graphene electrode modifier. The use of this mass increases the oxidation current (Ipa) of phenol by 450 A, which is observed at an oxidation potential (Epa) of −0.30 V. The presence of interfering ions such as K+, Fe2+, and OH− can decrease the measurement current. However, based on the %RSD value, it shows that the performance of TiO2-graphene is in a good category, where the %RSD value obtained is 0.6%. TiO2-graphene electrodes can be used repeatedly for 12 days. Overall, this work demonstrates the potential of TiO2-graphene electrodes as electrode candidates for electrochemical-based phenol sensors.

Multisensor and Multitemporal Data from Landsat Images to Detect Damage to Coral Reefs, Small Islands in the Spermonde Archipelago, Indonesia

Nurjannah Nurdin,Teruhisa Komatsu,Agus,M. Akbar AS,Abdul Rasyid Djalil,Khairul Amri 한국해양과학기술원 2015 Ocean science journal Vol.50 No.2

Coral reefs are important because of their high biodiversity and their key role in the tropical marine biosphere. Furthermore, coral reefs are very valuable as a socioeconomic resource as they make important contributions to the gross domestic product of many countries. Thus, it is very important to monitor dynamic spatial distributions of coral reefs and related habitats dominated by coral rubble, dead coral, and bleached corals. Despite these natural and socio-economic advantages, many factors are threatening coral reefs. The study site was selected in Spermonde archipelago, South Sulawesi, Indonesia because this area is included in the Coral Triangle, recognized as the epicenter of coral diversity and a priority for conservation. Images of Landsat MSS, Landsat TM, Landsat ETM, Landsat ETM+, and Landsat 8 data were used to examine changes in the coral reefs of Suranti Island in the Spermonde Archipelago during forty one years from 1972 to 2013. The image processing includes gap fills, atmospheric corrections, geometric corrections, image composites, water column corrections, unsupervised classifications, and reclassifications. Fill Gap processing was done on Landsat ETM+ SLC-off. Subsequently, a multi-component change detection procedure was applied to define changes. Shallow water bottom types classification was divided into live coral, rubble and sand habitats, dead coral with algae, rubble, and sand. Preliminary results showed significant changes during the period 1972-2013 as well as changes in coral reefs, likely explained partly by destructive fishing practices.

The Impact of Sharia Compliance on Sharia Hotel Services and Customers Satisfaction

Hardius USMAN,Nurdin SOBARI,Fahadil Amin AL HASAN 한국유통과학회 2020 Asian Journal of Business Environment (AJBE) Vol.10 No.3

Purpose: The main purposes of this study are to examine what the most important hotel facilities that sharia hotels must provide, and to study the relationship between importance of sharia compliance and Muslim tourists' judgment on the performance of sharia hotels. Research Design, Data, and Methodology: The data were collected in Lombok Island. Questionnaires were distributed to Muslim tourists who stayed at one of the sharia hotels, with a total sample of 205 respondents. Factor Analysis Method and Two Independent Sample Tests have been applied in this research to analyze and interpret the data. Result: The results show only one factor is formed from all statements of Sharia compliance variable, and there is a significant difference in the customer experience and customer satisfaction ratings based on the importance of hotel facilities. Conclusion: The present study revealed that Muslim tourists who place a high level of importance in sharia compliance present a more positive assessment for all services provided by sharia hotels. The assessment from Muslim tourists with higher level of importance in Sharia compliance is more positive about their experiences during their stay at the sharia hotels, which also affects their satisfaction.

조직구성원의 소셜 미디어 사용과 정책에 대한 탐색적 연구: 페이스북을 중심으로

서우종,Syamsul Nurdin,홍진원,박재호 경성대학교 산업개발연구소 2012 산업혁신연구 Vol.28 No.2

오늘날 소셜 미디어의 사용이 널리 확산되면서, 대표적인 소셜 미디어인 페이스북의 근무 중 사용이 증가하고 있다. 이러한 시점에서 조직들은 직원들의 페이스북 사용에 대한 정책 수립의 필요성에 직면하고 있다. 조직들이 효과적인 정책을 수립하기 위해서는 우선, 페이스북 사용에 영향을 받을 수 있는 잠재적 요인들이 페이스북 사용 정도에 따라 어떤 현상으로 나타나고 있는지 살펴볼 필요가 있다. 따라서 본 연구에서는 페이스북 사용에 영향을 받을 수 있는 5가지의 잠재적 영역들-지식경영 활동, 직무 성과, NWRC(Non-Work Related Computing), 사회적 자본, 직원 웰빙-을 중심으로, 이것들이 직원들의 페이스 사용 정도(고사용자, 저사용자)에 따라 어떤 현상을 보이고 있는지 분석하였다. 또한 조직의 페이스북 정책의 존재 여부 및 유형에 따라 직원의 페이스북 사용 정도에 어떠한 차이가 있는지에 대해서도 분석하였다. 분석 결과, 페이스북의 접속 빈도를 기준으로 한 고접속 집단과 저접속 집단 간에는 5가지 영역에 차이가 없었으나, 페이스북 1회 접속당 체류 시간을 기준으로 한 분석에서는 고체류 집단과 저체류 집단 간에 조직구성원의 지식창출, NWRC, 연결적 사회적 자본, 직무 성과 영역에서 차이가 있었다. 또한 조직의 페이스북 정책과 관련해서는 단순히 정책의 유무가 아니라 정책의 핵심이 허용이냐 금지냐에 따라 직원들이 업무 중에 페이스북에 접속하는 빈도와 1회 접속당 체류시간은 차이를 보였다. 이러한 연구 결과는 조직 내에서의 페이스북 사용의 잠재적 영향력에 대한 정보를 제공함으로써 페이스북 사용에 대한 조직의 정책 결정에 도움이 될 것으로 기대된다.

Status of seaweed (Kappaphycus Alvarezii) farming land ownership and business productivity in Sulawesi Island: quantitative study

Sri Suro Adhawati,Nurjannah Nurdin,Hasni Yulianti Azis,Badraeni Rustam,Muhammad Akbar,Agus Aris The Korean Society of Fisheries and Aquatic Scienc 2024 Fisheries and Aquatic Sciences Vol.27 No.1

The aim of this study was to analyze the income and productivity of seaweed farmers based on farmed land ownership status. This research was conducted in three provinces on the Sulawesi Island which are ranked among the 10 largest seaweed producers in Indonesia: Central Sulawesi, South Sulawesi and Southeast Sulawesi. The twelve study sites were determined based on 5 special criteria and 792 respondents fulfilled the criteria for seaweed farmers. Data were collected through field surveys and analyzed using qualitative and quantitative methods. Results showed that the seaweed farming areas are considered as private property with 4 types of marine land tenure or ownership status: own land, inherited land, leasehold land and purchased land. The productivity of seaweed farming land had a positive value greater than 1 in South Sulawesi and Southeast Sulawesi, and a positive value of less than 1 in Central Sulawesi. Seaweed cultivation in Central Sulawesi has not been managed effectively. At all sites, the maximum number of growing season cycles was 5 cycles/year. Optimal growing season conditions gave the highest marginal returns at 2-3 cycles/year with additional costs exceeding additional income for more than 3 cycles/year.

Introduction of Geospatial Perspective to the Ecology of Fish-Habitat Relationships in Indonesian Coral Reefs: A Remote Sensing Approach

Shuhei Sawayama,Nurjannah Nurdin,Muhammad Akbar AS,Shingo X Sakamoto,Teruhisa Komatsu 한국해양과학기술원 2015 Ocean science journal Vol.50 No.2

Coral reef ecosystems worldwide are now being harmed by various stresses accompanying the degradation of fish habitats and thus knowledge of fish-habitat relationships is urgently required. Because conventional research methods were not practical for this purpose due to the lack of a geospatial perspective, we attempted to develop a research method integrating visual fish observation with a seabed habitat map and to expand knowledge to a two-dimensional scale. WorldView-2 satellite imagery of Spermonde Archipelago, Indonesia obtained in September 2012 was analyzed and classified into four typical substrates: live coral, dead coral, seagrass and sand. Overall classification accuracy of this map was 81.3% and considered precise enough for subsequent analyses. Three sub-areas (CC: continuous coral reef, BC: boundary of coral reef and FC: few live coral zone) around reef slopes were extracted from the map. Visual transect surveys for several fish species were conducted within each sub-area in June 2013. As a result, Mean density (Ind. / 300 m2) of Chaetodon octofasciatus, known as an obligate feeder of corals, was significantly higher at BC than at the others (p < 0.05), implying that this species’ density is strongly influenced by spatial configuration of its habitat, like the “edge effect.” This indicates that future conservation procedures for coral reef fishes should consider not only coral cover but also its spatial configuration. The present study also indicates that the introduction of a geospatial perspective derived from remote sensing has great potential to progress conventional ecological studies on coral reef fishes.